Deck the halls with bubble wrap? In order to insulate a room, would it make sense to apply a layer of bubble wrap to my walls/ceiling? What about some other material like mylar or foylon? What major factors would affect the answer to this question? In particular, would the amount of sunlight coming into the room have a significant effect?
If yes, how much benefit would I get from <100% coverage, e.g. from missing some uneven spots on the wall or missing the ceiling?
(Context: I am already taking a number of steps to insulate my windows. I am also a renter of a second floor unit with somewhat irregular construction, which I take to mean that it is a hassle for me to modify the exterior or the inside of the wall and I cannot assume that "best practices" were followed in the construction process.)

I would select non-flammable insulating materials such as rock-wool, or fiberglass (fully puffed up; mashing it badly hurts its performance).  To use these, you will need some sort of framing to hold it up.  It can't just be taped to a wall.
It's not out of the question to frame a room inside a rental house; I've seen it done. However this is the wrong year to be buying lumber and building supplies: COVID shut down the logging and milling earlier this year, meanwhile everyone stuck at home has gone on a remodeling binge, meanwhile new-home construction remains a very strong market.
However, you really need to work the normal insulation priority list: sealing of doors and windows first, window treatments second, then walls pretty much last.


If they can put a man on the moon, why can't they build a 'composter-friendly' under-sink disposal? If they can put a man on the moon--and add wi-fi to our thermostats--why can't  they build a  'composter-friendly' under-sink disposal?

I'd love a disposal that could send the ground up 'solid waste' to a bucket for easy transport to a compost heap and send water down the drain. Does anyone make this? Why not?

Ideally, good design/engineering would minimize mess and overflow (e.g. with some type of gasket) , alert you when the 'compost bucket' needs emptying, work correctly if the bucket was full/etc.

I see the following advantages:

disposal cuts food waste into small, quick to decompose size
disposal would co-mingle all waste foods into a "compost slurry"--mixing leftover food scraps with banana peels and orange rinds--rendering it inedible to pests
allow the low-green/high-"ick" household residents to have a consistent means for disposing food waste. (i.e. in my household, one resident gets "grossed out" by having a compost bucket near the kitchen. she would just use the disposal and not have to worry about it).

I would loveto have something like this in our house and would appreciate any insights.

thanks

While this would have real potential if you could do it, as there are many people who do seriously get into composting (I am one who does try), it has some problems.

The main problem is how do you separate the water from the solids, while leaving it at least slightly wet. Compost needs some water content, and if you pack the solids too densely it won't decompose easily. You would almost need to re-hydrate the solids for them to be composted if you remove too much water.

So, how do you remove the water? I can see a few ways.

Filter it out. But any sieve that has holes in it that will allow water to drain out, but holds back most of the solids will get clogged too fast.
Squeeze it out, using some sort of trash compactor design. Again, one would need to work it out where the water goes, and then deal with the solids in an automatic way.
Centrifugal action, so something like a washing machine spin cycle.

Any of these schemes need to remove just enough water, but not all of it. It is not an easy problem to solve.

What we do, that seems to work, is leave a 5 gallon bucket in the garage. When we have kitchen waste, veggie peelings, etc., they go into the bucket. Every few days, I walk down to the compost pile with the bucket and a pitchfork and turn it over, adding the new material. This works quite well. (Another major part of our compost pile is shredded paper from our paper shredder, plus shredded leaf waste.)

This is a low tech solution that works splendidly well. Yes, some of the material would compost faster if it went through a disposal grinding process, but low tech often has advantages.

It is cheap.
It never needs repair. (Ok, some days my back hurts.)
No electricity required.
It gives me some exercise, never a bad thing.
It forces me to go out and turn over the pile once a week or more. This gets air into the pile, as well as tending to keep it free of animals due to the frequent activity (who would otherwise wish to nest in the pile.)


What size and type wire should I use to pigtail to my light switches? what's more common for  light switches at home, 12 gauge or 14 gauge wire? how do I know what I have?
I need to pigtail my ground and neutral wires to connect to my new leviton decora smart light switch. what do I ask at home depot to buy these pigtail ground and neutral wires?
what does it mean by NM-B wire or THHN?  I don't know which one to buy for my light switch, and don't know the exact specs to ask for. thanks

Turn off the breaker for the device. Is it a 15-amp breaker? Use 14 gauge for pigtails.  Is it a 20-amp breaker? Use 12 gauge for pigtails.
Buy a few feet of the appropriate color of solid THHN and wirenuts. (THHN also comes in stranded, in this case you don’t want that.) As noted in a comment if you mean that you are going to use neutral as a bootleg ground, that’s a big no-no.
NM-B, or Non-Metallic sheathed cable is a multi-conductor wire with at least hot/neutral/ground, commonly called Romex.  THHN is a single conductor wire.


What is causing my circuit breaker to trip instantly and trip the next breaker too? Update - Video Added One of my circuit breaker trips instantly.

I try to reset it but it trips immediately and trips the breaker under  it too.

I can reset the break next to it and it is fine until I try to reset the problem breaker again.

Could the breaker itself be bad? and if so could I swap it out myself?

How would I find which outlets, light, fans are powered by this possibly bad breaker?

Update: I added a video showing the exact issue.

http://www.youtube.com/watch?v=WOfW-rqeqkM

Somewhere in the circuit there is likely a low resistance connection between the two legs. The most likely culprit would be a split duplex receptacle that was replaced, and the tab between the upper and lower sections were not removed. Another likely cause would be a staple, nail, screw, etc., that penetrates both cables.

With both breakers off, check continuity between the ungrounded (hot) conductors of each circuit.

Turn off both breakers.
Set your multimeter to continuity mode, or the lowest resistance setting.
Touch one probe to the lug of one breaker, and the other probe to the lug of the other breaker.

With the breakers in the off position, you should read infinity (or open).   If you get a reading, it means that these two conductors are connected somewhere.  If the reading in not close to 0, there could be a 240 volt load connected between the legs. If the reading is near 0, you have a low resistance short between the legs.


How can I install a timer with three-way switches? I currently have a set of lights controlled by two switches. I believe they are both three way switches, I know one of them is.

I am trying to install a timer while keeping the three way switch function. The timer has three wires: Load, Line and Neutral. Model RPLS730B. I need help on how to wire this.

I do not know how the setup is currently wired as far as what each wire does. From observation it is wired as shown below.

Switch 1:

 Black

 Black               Red

 Whites are tied together

Switch 2:

 Red                 Black

                     White

Additionally if someone could explain the current setup and the circuit of each wire that would be great. I do not understand how they are connecting to the lights.

:edit: The traveler on switch one is Black and the traveler on switch two is White.

If you have more than two screws on a switch it's probably a 3 way. The other option would be a 120v/240v switch or something like that for a motor load possibly. If you have a black screw where the red wire is tied to on each switch, it's a 3 way. Yours are probably both 3 ways. They would not operate if they weren't. Anyway here are a few variations on how to wire that up:

http://www.wfu.edu/~matthews/courses/p230/switches/3way/variations.html

great and easy to follow!

Forgot to mention the timer has to be a 3 way timer as well. From the pdf you linked it didn't look like it was unless I missed something. I know a lot of those are both single or 3 way depending on how you want to use it.


Am I correctly replacing 2 x two-pole breakers with a quadraplex breaker? I am replacing the top two of those two pole breakers in the top left (green) with one quadplex with common trip model EATON BQC220220. Is the attached wiring diagram right(just follow the dots color where wires will go / interconnect)? I really appreciate the help
I need to make room for a 50 amp double pole breaker for the generator that will go to the top left after the quadplex install.
I will also add a main breaker in the empty space with the proper interlock.  I do have another main breaker outside.

enter image description here

Sure, if it fits
Your panel labeling specifically lists the BQC type breaker, so that's alright.
Your wiring (one pair in middle, one pair outside) is correct.
The breaker appears to be "common trip, both inside and outside" so that is either correct or overkill for your circuit, so that's fine.   (Beware Eaton "Non-common-trip" types).
However, your panel is labeled for BQC breakers only in certain places depending on whether the bus stabs have a forked tongue.  The label is not specific as to where that is in your panel, but given that it's a 30-space panel and the old CTL limits were 40-space, I'm guessing it's the bottom 5 rows of spaces.  Which are mostly populated already.
Might be time for a subpanel
As you are seeing, 30 spaces/40 circuits is inadequate for a modern house.  A better use of 2 spaces might be to feed a subpanel, so you can offload some loads into that.
If you had any thought to having a "critical loads" subpanel to support future generator or battery/gen/solar backup system, this would be a good time to think about that.
Normally I recommend a house finish with about 50 spaces, so by that a 12-space subpanel would suffice; however, since your house is so full already, I'd aim for more like 60, suggesting a 24-space or 30-space subpanel.  Scrimping on spaces is a futile gesture; the price difference is tiny compared to the frustration of - well, you know exactly, don't you!  You spent more on that BQC breaker than the price difference would've been for the last guy to buy a 40-space panel instead of the 30. So why not? Spaces are cheap, make the sub a 40-space. Never run out of spaces again.


Can I run these plumbing lines like this? After calling about 8 companies and only having two come out who no longer answer, I'm going to give this one a shot before throwing in the towel. This is via permit and I'd like to be super sure before the inspection. This is in Michigan and I believe we follow a modified version of the 2015 IBC, if that helps at all.

I have a small old room that had been modifed to be a laundry room and we'd like to make it a bathroom. It is on the second floor of a house, with a 3" waste/vent in one of the walls. The proposed layout is shown here:

The red circle is the waste stack. The following image shows sink (bottom left), shower (bottom right) and toilet (top) drain locations and how I think they should connect to the drain. The joists are 2x10, but actual is a hair less than 9 and have been sistered. The top plate runs under the toilet and the toilet drain would enter an interior kitchen soffit before turning to the stack.

The toilet is on 3", shower on 2", sink on 1.5".

I have the following questions if you could help:

Does the run distance for the sink and/or shower require venting? I think it's ~4 or 5 linear feet in sink drain option 2 to the shower drain. Shower drain is ~6 or 7 feet to the main stack.
Addendum to above: There is a much closer 3" vent stack a few feet behind the wall - are the vent and drain pipes required to be the same?
I can't figure out a location to put a cleanout - is it required and where would be a good spot?
I think reaming out the existing/newish sanitary tee on the 3" stack (see below) and fitting a 3" street tee makes sense. Right below it, you can see another sanitary tee from a toilet in the next room. Issues with that?
Initially, I was told by the plumber they don't usually see pressure tests with this kind of stuff when inspected, but in the case of it being necessary, how could I possibly set that up?

Thank you for your time.
Some views of the stack from in the soffit:

What is the total number of fixture units that you have on your 3" line?  The clean out is not necessary, provided you can access it from the roof or another clean out is further up line. additional venting is not necessary. From viewing your photos, I would call in a professional plumber and have the repair done correctly and have someone that can be called back if some thing goes wrong. One last bit of advice, contact your local authority and have them look at your sketches of what you are doing, this could be the best way to get the information that you are looking for.


can I cut in / blend old brick extension Our house was extended some time before we moved in and it has left a straight line of mortar running down the front and back of the building went instead of cutting out the half bricks that wrap around they have just fixed cut bricks.

I'm assuming this was just a lazy developer rushing the job..

It's it possible for me to work my way up and cut out every other brick and fit a new to join the two buildings back together?

The brick work all lines up correctly between old and new so the replacements should be perfect.

If I'm mistaken and this is actually standard practice could I perhaps cut out around a third of the half bricks depth and re-face them with a slice?

Yes, you can cut out and bond in new bricks to get a seamless match in the bond (assuming the gap is not an expansion joint - if it's mortar-pointed it's unlikely to be; an expansion joint should have sealant in it).

The main issue that you will run into is likely to be the ties used to fix the new wall to the old. If wall starters were used, they'll run right the way up the height of the wall in the joint and be in the way of where you are looking to put the new bricks. As you are bonding it with new brick, you won't need to worry about replacing any ties you have to take out.

Re-facing the bricks will be a hell of a job - the bricks will be hard and it won't be easy to tacke the face off in situ. Plus you'll need a diamond saw to cut faces off the new bricks (or to buy slip bricks from a merchant - most will be able to get these to order). My biggest concern with that would be ensuring that they are suitably bonded so that the faces don't blow off with freeze-thaw.


Self-leveling alternatives to gypsum concrete (Gyp-Crete, Pyrofill, Securock) over OSB? Replacement options for < 1.5 inch pour?

Details:  Bathroom remodel (new tub, tile wall/floor, toilet, vanity).  Old tile floor came up with finger pressure, found that the gypsum concrete underneath was unstable, coming off in large loose pieces, and mildewed.  Removed all gypsum concrete in the small bathroom.  OSB is in great shape.  Supplemental goal to install underfloor radiant heating.

We generally don't recommend self leveling alternatives on a substrate other than concrete, vibrations over time can affect their stability. Best option is shims and plywood.

That being said, you're asking for a self leveling option. Your best bet would self leveling concrete, you'll need to pay attention to the substrate requirements, it says it accepts certain wood based substrates, however compare their requirements to your situation.

like:
http://www.lowes.com/pd/MAPEI-Gray-and-Silver-Indoor-Floor-Patch-and-Leveler/1180155

Also, most of these 'concretes' are safe for electrical radiant flooring installations.


Mystery Part from Stihl Chainsaw I opened the case of my Sthil MS311 chainsaw and found a recessed screw in the case, but I cannot find where it came from (saw wrench head for scale).  It seems to be a something used to hold liquid, because of the rubber gasket.  The saw ran fine for a long time (about a year).  It's been acting up lately, not sure if this is the cause.  By acting up, I mean it starts fine, but it seems like the chain isn't getting enough bar oil, causing the chain to bind up.
I searched though the parts list on the usual sites, but cannot find it.
Any idea what it is and where it goes?

The rubber gasket is a vibration isolation mechanism, not a liquid holding mechanism, based on experience with the parts of my Stihl saw (different model but those parts are similar.) All the mounting points between the handle/frame and the saw motor use those rubber-mount nuts.
While lacking a convenient exploded parts diagram, the manual I found does have a list of things to check when the bar is not getting enough oil.
https://stihl.partsmartweb.com/Catdata/EMP_IMG/STGSTH/Images/SERVICE/00590215.PDF


Lead paint test showed positive hours later I'm getting some work done on my house and the guy doing the work wanted to test for lead paint. He scratched an area on a window sill, rubbed it with the spongy tip of a swab, and immediately declared it lead free cause it didn't change to the color of red. However, I just walked into the room three hours later and see the two spots he tested are both red. So what should I think of that?

I presume his test kit is designed to give an immediate result and, hours later, might be showing residue of lead from decades ago. Or perhaps just the breakdown of the chemicals in the test. I don't know.

EDIT: From looking around, one "instant" lead check swabber recommended by the EPA said theirs gives results in 30 seconds. We weren't in the room long but it was longer than 30 seconds.

I'm Lead Certified. That's orange, not red. That's just testing positive for Penetrol, or some derision thereof. It makes paint flow better. Not a danger to you or your windowsill lickers.


Tempered Glass in Window adjacent to Patio Door Is tempered glass required in a window within 24 inches of a fixed glass panel of a two panel sliding patio door?

As Ecnerwal noted, IRC code of 2018 required "glass within 24" of ANY doorway to have tempered glass if the glass within the 24" distance was LESS THAN 60" off the floor level".


Is fiberglass mesh tape a good choice for drywall? I'm going to be doing some drywalling shortly and was wondering what experiences other have had with the self adhesive fiberglass mesh tape.

Is it a good choice or am I going to regret using it?

I've found that it works OK, but it's more difficult to get the surface smooth than paper tape -- as the mud dries, it shrinks, so the mesh starts to show through.  Obviously this is not a problem if you're going to be doing some heavy texturing afterwards.


When painting with a roller sometimes it feels uneven, like the cross-section is an oval rather than a circle. What am I doing wrong? Sometimes when painting with a roller it feels like instead of the roller being circular in the cross-section, it is an oval.   Or perhaps the paint is loaded unevenly? I have been loading paint from a tray but dipping it in the paint and then rolling it on the raised part of the tray.

When I move the roller on the wall, I can feel the unevenness although there is little visible difference in the paint applied.

Am I doing something wrong?

As some have said cheap can be a problem, are you loading the roller with paint evenly and working it on the cross hatched section of the pan?  I will roll into the paint lift and back up roll into the paint 3 or 4 times depending on how full the tray is. After loading I roll on the crosshatching or ribbed section lift and roll to even out the load of paint and reduce dripping.
With good technique even a cheap roller will provide even coverage and with bad technique the most expensive roller wont make a difference.

As we can’t see what you are doing try paying attention to how you load the roller, this is how my dad showed me decades past and even though I hate painting I can do a nice even job using this method.


Is there any reason testing the neutral line on a dimmer light socket wouldn't work? I am repairing a vintage lamp and replacing the socket with a dimmer socket.

When I do a continuity test on the old socket, both the hot and neutral lines work. That is, they make a high-pitch noise telling me the circuit is closed.

Now, when I try this same test with the new dimmer socket, the continuity test only works on the hot line. I don't get any indication of a closed socket when testing the neutral line. Conventional wisdom tells me that there is something wrong with this socket, but I actually went back to the store and tested another socket, and experienced the same thing.

The old socket is dead-simple -- there are no special electronics in it. The new dimmer socket is a lot more complicated with a potentiometer, capacitors, resistors, etc:

My question is, is there a logical/electrical reason that this socket works correctly, but doesn't give me a successful continuity test on the neutral line?

Figure 1. A typical triac-based dimmer switch schematic. Source: Homemade circuits.

Your continuity check is being interrupted by U1, the triac. This is a semiconductor switch which can vary the amount of the mains waveform getting through. Read the linked article for more.


Can I use sliding barn door hardware on a hollow panel door? I purchased standard 6 panel hollow interior doors and one door way is much smaller.  Can I use sliding barn door hardware to hang this other wise standard hinge door?

Depending on the exact sliding hardware you are using, it should be possible. Hollow core doors usually have a solid wood frame along the edges, though how far into the core this frame extends may vary.

If you are using hardware like that shown below, you would need to make sure that the brackets attached to the wheels are anchored into the solid wood frame at the edges of the door.


How should I apply spray foam around a ceiling mounted bathroom exhaust vent? I have a ceiling mounted exhaust fan that has a substantial (2-4" air gap along the sides after it was installed such that when it is running a lot of the air just gets pushed back around the sides of the fan.

I'm thinking of applying some spray in foam around the fan to get a better seal around the fan to prevent this. That foam is some nasty stuff and I don't want it just dripping back down on me as I apply it overhead into the gap.

Is there a method for spraying foam into an open space overhead safely to avoid a big mess underneath?

Rather than using that spray foam you'd be better off getting a sheet of Styrofoam and cutting it to fit the opening around your fan. Make a template out of cardboard and then trace it on to the Styrofoam, cut it out and fit it into the opening. You can then caulk around it sealing it further.
Now, you need to make that direct connection to the duck you said was already in the attic. You're looking for trouble venting hot, moist air directly into your attic/crawlspace.


Replaced light fixture, now 3 way switch doesn’t work I replaced an old lighting fixture with a remodel can and led trim, but in doing so the three way switches no longer work.

I didn’t touch either switch’s wiring, but now the switch with the circuit running to it has to be on for the other switch to function. If the first is on, the other switch can turn on and off the light, but if the first one is off, the second switch doesn’t work.

My next step is to pull out the switches and check the wiring, but I’m curious if replacing the light could have affected the switches somehow?

EDIT: now with photos

Sometimes a NM cable is not fastened down along its length, either because it was fished through an existing wall (old work) or because the builder just laid it between the attic joists (poor work).

If the NM cable that you moved is not thoroughly fastened down, and if the strain relief at the other end is inadequate, then you probably moved the wires or wire nuts around inside the box at the other end and knocked one of the travelers off its terminal.


Can I cut out a 12" section of a footing to run new plumbing in a basement? I am finishing my basement and need to run plumbing to the planned bathroom. To do so, I need to cut out a 12" section of a footing (can't go under it). The section in question is under a door opening. Can this type of footing be cut into and removed?

You can do it, but you may want to check with your local building official for local requirements.
The normal way to do this is to core drill through the wall/footing and insert a protective sleeve two standard pipe-sizes bigger than the drain.  For a 3" bathroom drain that calls for a 6" nominal Sch40 pipe which has a 6-5/8" outer diameter.  That's a big job and you may want to rent a core drilling rig for it or hire somebody to come do it.
You could also use a rotary hammer; in fact, you may need one anyway if you have to chip around rebar to cut it out.
Why is your sewer line not low enough to go underneath your footing?  That seems unlucky.  If the sewer line isn't very long it might be easier to replace it.  Try to find out how deep your city connection is and whether re-laying it would be an alternative before cutting through your footing!


Pros and Cons of a Pole Barn House Just ran across the idea of using a pole barn for a full time house. We would use it more for a cabin (barn) in the woods but the idea is intriguing. Everything I read says its more affordable but outside of the sure size and heating the barn, what sort of pros/cons come into play with using a pole barn as a full time house.

Additional is steel framing more optimal as opposed to wood?

-Dalton

Depends on the building codes where you are located to determine if a pole barn is an acceptable structure for habitation. In most jurisdictions it would still require all of the same creature comforts such as insulation, plumbing and electrical to be habitable.

At that point it's really just a house framed like a pole barn which would give you the ability to have lots of free interior space without the need to put in supporting walls. You would most likely need some interior beams and posts but no need for full walls.

I've been to several "venues" that were old barns converted into entertainment spaces. On really hot days it seemed like you could smell the 100 year old wood leaching out the chemical smells of urine from decades of farm animals peeing on the walls. So just a thought when considering living in a barn. If it wasn't used for housing animals you probably wouldn't have the smell issue.


Should I purchase single tools, or a tool set? I now happen to need a wrench to make some changes to my bed. I also realize that sometimes I may need other tools in my life as well. I was wondering

Which way to build one's own collection of tools is better, buying one after another, or buying a tool set?

I am living in U.S., if that helps.

Choose high quality for the most commonly-used tools.

There are a lot of crappy tools out there, many of them sold by Harbor Freight at rock-bottom prices. Those tools only make sense if you plan to use them very rarely, and if you will use them very gently, and if you can't rent them nearby.

For the tools you use most often, buy the best quality you can find. Working with good tools is a joy; working with crappy tools is very frustrating.

Don't buy every tool you could imagine using. While "the right tool for the job" makes the job go smoothly, buying all the "right tools" means you'll spend all your time organizing your extensive tool collection.

Buy tools that match the work you like to do. I haven't seen your bed, so I'm not sure how it's put together. It sounds like you plan on only very minor tinkering. With that in mind, I recommend you buy:

an adjustable wrench
a flathead screwdriver
a philips-head screwdriver

These 3 tools will let you do a lot of tasks. I'm guessing that will be enough for you. Beyond that, see the question that @NiallC linked to.

Regarding kits:

Kits sometimes sell on false abundance. That is, you see 100s of shiny bits and pieces and think "everything I could need, wow!". They may have duplicates (my socket set has four 10mm sockets!). They may have items you'll never use. And they may have low quality, hiding behind the size of the collection.

Kits often come in a nice case, making it easy to organize and store your tools. Unfortunately, if you need 1 more bit/socket/attachment/whatever than what comes in the kit, you don't have a good place to put it.


Glue for shredded cork My inlay soles are wearing and renewing them is expensive (they are custom made for my feet). I decided to make my own by making a mold and filling the mold with shredded cork. I have not done any experiments jet but was planning on using wood adhesive to turn the granulated cork into one piece of agglomerated cork. What adhesive should I use for cork?

Clay mold:

Example of agglomerated cork from wikimedia:

Just found a website describing parts of the process, the wine bottle corks are produced here with polyurethane. It also seems to be frequently used in cork floors.


Painting over glossy paint I'm sanding the glossy paint of my bathroom before painting over it. But I realize it's hard work and I find the sanded surface still kinda glossy. Actually I have no idea how it should look like in order to qualify as a suitable surface to paint over it, nobody discusses this aspect in the web pages I came across, they just advise to sand. But to which extent, until seeing what?

Surface prep is one of the most important factors of painting, it takes most of the time. If the surfaces are clean of environmental contaminates, fireplace and cigarette smoke for example or hand prints around door knobs, then you could forego wiping down the trim or places were heavy deposits of "stuff" build up.

There are "liquid sanding" compounds that dull a surface to eliminate sanding, But I can't vouch for those. Hand sanding at best for detail areas, use a pole sander for larger wall surfaces, use 120-180 grit if you plan on priming the wall again. This will be needed if you plan on changing the color to something that may not cover on one coat. Use 220 to de-gloss the surface, if the finish paint can be done in one coat. Otherwise you can see the scratch marks through the finish coat (with heavier grit), if you use gloss paint. This effort over the old paint will also remove other debris that inevitably gets in the wet paint as it is applied or while it dries, such as lint, hair and fuzz, paint runs, you name it.

Use the what may be now the not-so-reflectiveness of the once was glossy paint to determine how well the scratch pattern is on the wall.

With a pole sander, it may only take an overlapping pass in each direction (left to right, top to bottom) to accomplish this. This will help keep track of what you done already. Better than waving around all over and hoping you caught all the area.

No sanding job will be 100%, the idea is that the new paint will have enough to bite into to hold up over time.

The visual amount to look for? Picture what a comb or brush for your hair would look like if it left marks on the wall after one or two passes. Of course, what you will be doing in reality will not be uniform as my word picture suggests, but the idea is to have more scratched wall surface than glossy, with no large spots that are still glossy like it was never sanded.


Mosaic installation: thinset excess spilling between the gaps I'm currently placing mosaic on a concrete staircase. When I push the tiles into the thinset often the thinset is spilling through the gap.
I'm removing the excess with a brush which is annoying because it moves some tiles from their place.

I'm wondering if that's a symptom of a wrong technique.  Thinset too soft? Too much thinset? I'm using a 4mm v-trowel.

Thanks, Gerard.

Your thinset should be like peanut butter.  If it is too thin then you could have possible issues with mosaics and flooring.  Basically you could push down to bare floor or close to it.

A 4mm trowel is perfect size for most mosaics.  I think that your issue is that either you aren't combing the area well enough after dropping down your thinset or possibly you are pushing down to hard.

The installation method for any tile but especially a mosaic is to comb the area in a direction, sit the tile on the area, then gently press the tile into the thinset perpendicular to the thinset streaks back and forth.  If you were to just press straight down hard you would have a lot of thinset in between your tiles and as mentioned before not enough behind the tiles.

Also you will always have a little spillover.  You don't have to clean out all of the thinset in between the tiles.  Your grout will bind to the thinset fine so you just need enough room for the thinset to not show.


How can I temporarily bypass a water heater? Is there a way I can keep my water turned on and bypass my water heater so I can have water in my home? It's a 30 gallon electric water heater... I can't get a water heater until next week..

If you expect to need to rework the plumbing for the new heater anyway, just cut off both the supply and outlet pipes and slip on a Sharkbite hose. They're not particularly inexpensive, but it'll make quick work of the temporary fix.


Are Cat6a keystone jacks suitable for Cat7 Ethernet cabling? We have already purchased 500ft Cat7 Ethernet cable. We wanted the high-quality cable running through our walls to be future-proof and to ensure we get Cat7 speeds (at least in the future). However, we seem to be having trouble finding Cat7 keystone jacks, while Cat7 cable and Cat6a keystone jacks are common.

I have also found sellers that say Cat6a keystones are suitable for Cat7.

Are they? Is this what we've been missing, that we're supposed to use Cat6a keystones with Cat7 cabling? Will this reduce the signal at all? Can we still get full Cat7 speeds this way?

Edit: Do you think I would experience any issues using Cat7 cables with Cat6a RJ45 connectors, for 10 Gbps speeds?

No, you won't get the 25Gb Cat 7 bandwidth with Cat 6a termination. For 25Gb speeds you need to terminate with GG45 (GigaGate45), ARJ45, or TERA, but not RJ45.

I think you should use 6a termination so you'll get 10Gb, but if 10+Gb becomes available in the future you can replace the terminations if needed.

GG45 is a product sold by Nexans that is backwards compatible with RJ45 at 10Gb speeds. ARJ45 is the ISO standard non-brand name that is similar to GG45 but might be easier to find. TERA is a product sold by Siemon, but isn't backwards compatible with RJ45, so it's not as common.


Why won't the brake release the drum (tub) in my Simpson 950 Eziset? When a full cycle is first started there is no "click" and the tub no longer turns as the machine does its "little bit of water here and a little bit there" routine before commencing the wash cycle. The agitator is working. Same when it come to rinse and spin or drain and spin: the water will drain, the agitator will spin but the tub is still locked so the agitator rolls all the clothes into balls against the wall of the stationary tub. I have changed the drain motor/brake solenoid unit for one known to work with no change to the above.

Can anyone point me in the right direction for finding why brake is not disengaging?

I have been unsuccessfully trying to solve a problem involving the brake/clutch on my Simspon Ezi set 750. So my hours are not totally lost I can report the sequence of events that happen during the wash in case this helps someone fix their machine. The click at the start is the cable solenoid retracting and disengaging the brake which then allows a few seconds of spin cycle which continues in bursts for about 1 min ( Presumably to allow the water to spray evenly over the detergent on the top or just wet the clothes ) . After this the cable retracts( Is loose) and the tub brake lever is engaged although ( And this is my issue) I think the pawl clutches'  purpose is to stop the bowl from rotating to the lock position as this locks the agitator and the bowl as one and is really only useful when the spin cycle is finished. My clutch doesn't seem to work properly and the agitator and tub lock together after the initial spin so there is no agitation and excessive motor load.
Perhaps this might assist someone, although Simpson is generally found in Australia and New Zealand.


Only 64 volts across the bathroom heater? What gives? In the bathroom, the vent-fan ceiling heater and light are all on the same hot wire. However, there are only 64 volts across the brian heater--which does not work. However the light and fan works fine.

How do I troubleshoot this problem?

I suspect that the hi-limit has been cycling because of insufficient air flow. (the blower fan is either plugged with dirt or the bearings in the motor are dry or both) The points on the hi-limit have arked to the point that they won't carry a load anymore.  You are just getting a carbon trail voltage reading.  Don't try to save this heat-fan-light. Replace it.  It is most likely a hazard.
If you purchase and install a new unit, make sure that it goes on a 20-Amp dedicated circuit complete with 12-gauge wire. P.


What could cause my bathroom exhaust fan to stop working? I've got a Vent fan with heater in the bathroom, and recently the vent fan stopped working while the heater worked fine. Thinking this might be just a bad switch issues, I took the cover plate off the switch and found that the switch itself was working. When in on position there was no voltage reading across the terminals, and when off I got standard 120 reading from the common hot to the heater terminal. From the common hot to the vent fan terminal, I was getting a fluctuating reading from like 60 to 80 volts (and yes my meter was in the AC mode)

the heater has its own fan which still works.

It may be unsafe to run the heater without a working fan.

Drop ALL the power to the room and remove the guts from the assembly. Usually the fan will have a short cord with a plug. Power it up and try to get it to spin (don't get shocked or bitten).

If it is fail you might be able to get a replacement from the manufacturer. IME this is hit or miss; sometimes I end up buying a completely new (same) fan and swap the guts so I don't have to install much. Manufacturers may not sell you replacement parts but they sure will sell you the whole thing...

Don't throw anything away. You may need the squirrel cage off the old fan motor if you can find its equivalent.

Verify the outlet in the housing is working properly.


Hose for connecting 3/8 inch nipple I have a hose that connects a water pump to a pressure tank.
The nipple is 3/8" I need to connect a longer hose, but all the 3/8 "faucet" hoses that I've found are too small for the 3/8 nipple.

. The 3/8" hoses that you have will not thread to a 3/8" pipe nipple since the connectors are for 3/8" compression fittings which are different than 3/8" pipe. You need to find/buy flexible hoses with connectors that connect to 3/8" pipe. Talk to the people in the store that you are purchasing the hoses from to get the correct ones. Also, add a picture of what you are trying to accomplish. You may be able to adapt washing machine hoses or something similar for your use.


How do I use this valve properly? I have a valve in my heating system that I don't understand. I have searched on the internet but I haven't been able to find any information on it. What I do know is that the valve's purpose is that of maintaining the pressure in the system, but I don't know why there are two controls or what each of the two controls do. All other pressure control vales that I've seen have just a single control.
The two controls are marked in the photo. There is a hand operated valve ( similar to a tap ) on the bottom and there is a screwdriver operated control on the top with a + and - on it, but turning it doesn't seem to do much if anything and it doesn't appear to have any stop it just seems to keep turning but I have only gone 10 or 15 turns before I turned it back, maybe it's more.

It's called a pressure reducing valve (PRV)
That's a PRV with a shut off and set point. The knob on the bottom is the shut off and the bigger knob with the screw is the set point. Now that you've adjusted it with pressure in the system you may have lowered it and you may need to remove some water to determine the set point. From the picture it looks like you're set at about 2 bar which is about 30 PSI in my neck of the woods 30 PSI on heating system is the upper limit and close to it or much beyond it will cause the pressure relief valve to pop.
What the pressure does
I'm not going to do the exact math but one BAR will push water up about 10 meters. So if the highest radiator in your house is around ten meters high from the point of measurement you would want your pressure-reducing valve set to maybe 1.2 BAR to compensate for errors.
What to do
If the only thing you did was turn the bottom one then no harm done. If you did adjust the top one you're going to need to remove some water but before you do that you're going to need to determine what the correct pressure for your system is. Often on that type of pressure reducing valve the screw on the top is what actually makes the adjustment and the black plastic is just a cap covering the housing therefore turning it has no effect.
In conclusion
It seems like you have not done anything to negatively impact the system but the fact still remains that if it is indeed a heating system the pressure may be set too high (depending on local codes and regulations). If it's a PRV for your domestic system (tap water) then 2 BAR is most likely close to the correct number (also depending on local codes and regulations).


Damaged wire while drilling wall caused power to go out. How to fix it properly? I managed to damage two wires/cables: tv/internet and a power wire.

There were three of power wires: a blue, a black and a green/yellow. I've damaged the black one, but just a little bit.

When the drill hit it, the power went out. I used a heat-shrinkable sleeve and some insulating tape; Is this sufficient to restore the wire to full power? Is it dangerous to keep it that way? Should I use a junction box to fix it? It's in a brick wall, so that wouldn't be very easy.

So it sounds like the AFCI breaker did its job and saved you from a potentially nasty jolt. The AFCI detects the arc (i.e. your metal drill bit contacting the live wire) and cuts the power.

If the wire wasn't severed, you can probably get away with just wrapping the wire in electrical tape and then wrapping the whole scar. If the wires were severed, you can use an inline splice to reattach them without a box.


One thermostat with a switch to control 2 heating systems I have a natural gas boiler and a pellet stove. I have a Honeywell programmable thermostat (2 AAA Batteries) that I have used independently with both of these systems. Switching from one system to the other requires rewiring the tstat.  Can a buy some kind of switch, preferably from Lowes or Radio Shack, that I can use to switch which system is being controlled?   Preferably something I could put inside of a wall remodel electrical box.

Why?  There are a number of variables. I sometimes have lots of pellets or none at all.  When it is very cold, I prefer to use both (pellet stove always on), but when it's warmer, just use the stove on the Tstat. Being able to switch without rewiring would be nice!

You just need a multi pole switch. If you are using a T-stat that uses batteries you may only be using two wires to actuate the circuit.

In that case get a double pole double throw switch. (If you are using three wires you will need a triple pole double throw.)

Like this one.

Connect your thermostat to the center terminals and the boiler and the wood burner to each of the other pairs of terminals. Then switch back and forth to your heart's content.

Good luck!


How to secure aluminium window lock handle that keeps falling off? The lock handle on my aluminium windows keeps falling off. The handle had previously fallen off when I first moved in a year ago and the landlord remounted it. Since then it has become loose a few times, but has been able to be screwed back in. Now the two screws no longer hold. The internal thread (?) on the window frame is only a few millimetres thick.

How can I securely remount this handle?

I am not sure of the screw size/type, but below is a photo.

The screw you're showing is a self-tapping metal screw.  It's designed to cut it's own channel into metal and grab hold by cutting it's own threads - but it's not meant for repeated uses because repeat uses can damage it's own threads, making its hole too big for it.

Take it to the local hardware store and get one that is slightly wider in diameter, and use it in place of the old one.


Dealing with water on a bad garage slope The slab in our garage has settled toward the house, so whenever our cars are slushy the snow drains into the garage, where we walk and have things stored.

We've been quoted about $4,000 to replace the slab, so that won't happen anytime soon. The concrete is severely chipped and flaking from 40 years of snow and salt, so I'm not really interested in mudjacking. And it's about 5" low across the entire garage (25') so self-leveling patch is prohibitive.

Is there any way to make a decently effective dam/water directing feature to keep this mess from getting everywhere? Anyone dealt with this in a somewhat effective way?

I have a similar situation, though due to poor masonry work rather than settling. Meltwater runs to the side of the garage near the house entry door, soaking the stair base and a shelving unit, along with any objects sitting there, with saltwater.

I intend to cut several channel drains into the slab at key locations using a rented diamond saw. Normally this type of drain would connect to a pipe running to the exterior (a "daylight" drain), or would have a deep drain pail below. For our purposes, this probably isn't necessary. I may excavate a small area below the drain unit and add pea gravel to increase capacity, though.

The idea is to catch the bulk of the water flow as it leaves the parking area. Water will settle into the soil below the slab. I don't believe that it'll be enough to cause further settling or other issues. We're talking about a few gallons per week at the most, and only during winter.


Cooker Hood Shorts When the Outer Cover Touches a Wall Bracket Installed to Stabilise the Cover I have installed a cooker extractor hood which works fine with the vertical outer cover off. When I rest the hood cover on the extractor base and it touches a high level wall mounted bracket installed to steady the cover (not bolted to the cover) the MCB trips?

I have a feeling you are in UK or Europe and your MCB includes RCD/RCBO functionality.**

The problem is that your device has residual current leakage, or what we in the states call a "ground fault".   It is leaking current in a way it should not, and which could stun/harm/kill a human. Being stunned unconscious onto a hot cooking surface would not be fun.

When you install the cover, you are causing the problem to manifest in a way that doesn't involve bloody mayhem.  This is a good thing.

The temptation would be to defeat the symptom, but the real problem is the hood is defective.  Sorry.

**if not, tripping the main circuit breaker and not the branch circuit breaker would require an arc flash brighter than the sun, and I'm pretty sure you would not be typing!


How should I eliminate gaps in wood-grain miter joints? I just installed some Cap-A-Tread vinyl stair treads. Basically, these are 5/8" thick MDF boards that wrap around existing treads and give them a new "look" because of a thin vinyl layer. The vinyl is a wood pattern that matches my floors.

The steps have an exposed side, and the Cap-A-Tread have mitered "returns" to deal with this. However, the miters aren't great, and there are decent-sized gaps on the outside corners. With crown molding, this isn't a problem as it's usually all white so a combination of caulk and paint could effectively hide any gaps. With dark wood grain, I don't really have this option.

What's the best way to hide the gap of a mediocre miter on wood-look vinyl?

I would probably use the same stuff you use to fill gaps in other laminate products.  I don't know how well it will hold up on the edge of a stair (in terms of working its way out of the gaps over time), but it'll at least blend in with the floor.  That stuff is made by a few companies in many colors to match a variety of laminates.  Should be available at your local big box hardware store.

For anyone in the dark about the Cap-A-Tread product, it's a laminate product designed to go over existing stair treads.  Kind of like the granite countertop systems that just lay on top of existing laminate countertops.  Looks like this:

It can also be ordered with a mitered edge piece that covers up the exposed stair end in the case of an open stair end, as OP is describing.  Basically a one-piece alternative to plank-and-bullnose for laminate on stairs.


Alternative to Silicone Wood Filler for Door Frame We're very nearly at the end of a very tiresome refurb of our downstairs area. As you can see from the photos, our builder has used silicone wood filler where the floor meets the door-frame. His reasoning is that any hard (setting type) wood filler would crack as you go through a year with the changes in humidity as the floor moves.

I think what he has done looks horrendous and I'm not happy with it. Does anyone have any suggestions as to what can make it look better?

The flooring is supposed to extend far enough under the door trim molding so that no sub-floor is visible.  The gap you have is non-standard and is completely unacceptable.

Presumably you have some scraps of flooring left. The installer should scrape out the filler and insert a piece of flooring into the gap.

EDIT

To be able to work in the scrap of flooring, the installer might have to cut off a small amount (say 1/8") of the door trim, but this would be inconspicuous.


Why does the shower get cold when I flush, and how can I prevent it? When the shower is running and someone flushes a toilet, why does the shower get cold (or sometimes hot) in some houses, but not others?

More importantly, would fixing that require replacing the water heater, or re-doing the piping in the entire house?  Or is there some cheap/easy way to fix it?

Why you get burned
One of the most common plumbing configurations, is a trunk and branch system.  This is where a larger diameter pipe runs from one end of the building to the other, and smaller diameter pipes branch off to supply rooms or individual fixtures. If any of the branches demands water (you flush the toilet), there is less water available to all the other branches.
Since the toilet only uses cold water, there is less cold water available to your shower when the toilet is filling.  This causes the water in the shower to be warmer, because there is less cold water mixing with the hot water.
How to stay comfortable
There are a few ways to reduce, or eliminate this burning feeling. Probably the cheapest, is to reduce the amount of water going to the toilet.
Reducing toilet water
You can reduce how quickly the toilet uses water, by simply closing the supply valve slightly.  This means the toilet will take longer to fill, but will reduce the temperature fluctuation in the shower.  Adjusting the supply valve can also have negative side affects, such as increased fill times, and noise.
You can also reduce the overall amount of water the toilet needs.  You can accomplish this by either buying a low flow toilet, or placing a brick, jug of water, or other object in the tank.  However, this method will reduce the amount of water available for each flush, so you may encounter difficulty clearing solids from the bowl.
Smarter mixing
Installing a new mixing valve in the shower, can reduce or eliminate the temperature fluctuations. Thermostatic mixing valves automatically balance the amount of hot and cold water being mixed, which will prevent drastic fluctuations in shower temperature. If the cold water flow is reduced (due to a toilet flush), the valve automatically adjusts the amount of hot water being mixed. This keeps the shower temperature more consistent, even when other fixtures are using water.
Increasing available water
Increasing the amount of water available in the system can alleviate the problem, but will likely require a major change to the plumbing.
If you have a trunk and branch system, increasing the trunk pipe diameter and/or the branch pipe diameter (if the branch feeds the entire room) will increase the amount of water available to the fixtures.
Distributing water evenly
A more drastic solution, would be to install a manifold with home runs.  This would likely require a major plumbing renovation, with almost all of the plumbing changed.
In this type of system, there is a central load balancing manifold.  Then for each fixture in the house, a dedicated pipe is run between the fixture and the manifold.
Supply and Demand
In the end, it's all about supply and demand.  If the demand is greater than the supply, you end up with a burnt butt. The only way to avoid uncomfortable showers is to reduce demand or increase supply.


How can I reconnect home ethernet that has been terminated outside? I recently moved into a newly re-wired house where the electrician terminated the ethernet wiring outside of the house.  Wires are coiled/zip tied into a box on the exterior wall.  The same box that the cable company patches their coax into.

What is the best way to activate this wiring?  There isn't currently power available outside, so patching them all into a switch seems like it is going to be a, well, challenge... :-)

To activate it you will need to create a network with a hub, router or switch. If you are adding broadband Internet access, you will need a broadband router which will share Internet access with the network.

Only thing is, the Ethernet cables should be terminated inside the house (unless you are planning to share your network outside the house). Home networking equipment is for indoor use only. This solves the issue with not having an electrical outlet.


How do I level areas of a wall that had peeling paint removed? In our bathroom, we have 'thick' peeling paint  on a section of a wall.  I started to peel off big pieces...and have stopped where it doesn't come off easily.  Now I'm left with a wall that is partially covered in a layers of paint and partially bare...just showing plaster.

So, the two surfaces are not level.  What can I use to level the bare parts of the wall upto the thickness of the painted areas?

A skim coat of drywall mud ("joint compound" when you are shopping - "mud" to anyone that uses it, normally.) Fill with a small (not wide) knife first, let it dry, scrape or sand any high spots (leveling), fill again with a wider knife, dry, scrape or sand any high spots, fill again with a yet wider knife (4, 8, 12" is my usual progression of knife sizes.)

Don't overwork trying to get it perfect when wet. If it's imperfect in the low direction when dry and leveled, do another coat (and let it dry, and level it) until it's as perfect as you need it to be. Strong, glaring light from the side will help to spot imperfections.


Can I attach a freestanding deck to concrete block garage wall? I'm certain you can't attach a ledger to cinder block that is why the deck is going to be free standing. However, I would like to know if the deck could somehow be secured to the garage. Kind of like what a ledger board does only without joist hangers as it is free standing.

Thanks in advance for any help.

The fact is that your deck's weight load must be carried underneath it and not using the cinder blocks supporting your garage.  That does not limit you from attaching it to the garage to provide horizontal stability and to keep movements in unison.

You would simply need to bolt in a faux ledger to the cinder blocks.  Make sure that you have at least two posts close to the garage that you are showing as the weight bearing points for that wall.  Any good inspector should realize this.

Note though your garage has been there for X amount of time and assuming it was made right, it probably isn't moving much.  Now build a deck and drop 4-8 posts in the ground - make sure that you are adequately putting these well below frost line and that they are big enough.  By attaching it to the cinder blocks there is a chance that your posts could cause upheaval on the garage wall. - especially with cinder blocks.


How can I install drawer slides so that they line up and work properly? I've got some drawer slides I want to use in some garage cabinets:

How can I make sure I install them accurately so that the drawer fits nicely and lines up right where I want it? If someone could provide a clear, complete tutorial it would be a big help to me and lots of other people.

There are a few tricks to drawer slides.  The main things to get right are to make them parallel and co-planar (same distance from the case bottom on the right and the left side, as well as level front-to-back in the case).  It helps if your case is perfectly square, so really focus on that.  You'll want to determine your drawer width based on how thick the slides are.

A good rule of thumb is to always try new drawer hardware in a scrap case to get a feel for how it works.  That way you'll work out any issues and not-so-obvious dimensions without having to fill in bad screw holes on your real project.

Here is a brief blog post on some Kreg jigs that assist in this process, and here is a YouTube video on how to do it using just spacer blocks to get everything flush and level.  Here and here are some succinct points to follow and another good video.  And last but not least, a good article on Rockler's site with some recommendations for jigs that ease the process.


After binding the three live (brown) wires together, remaining ceiling lights won't turn off I've got the three separate ceiling lights all on the same switch. The other two are simple with a single grey cable fitting. But this one is obviously the key light because it has three main grey cables.

When I wire up this one up according to the diagrams available online I find I can't switch the lights off.

I've used this diagram as a guide, though there are many similar. It fits my setup/wiring/colours almost exactly (except in my case the original installer has taped one of my blue wires (which I understand to be my "switched live") red instead of brown as in the diagram. I presume that's an entirely cosmetic difference.

So, retracing my steps I detach all the light fitting paraphernalia and just try it with the three brown/live wires bound together (as should be standard according to the diagram)  and still its sister lights (on the same switch) won't turn off. To kill the light I actually have to disentangle the three brown/live wires.

What am I doing wrong?

I guess this question looks much like this one, but the best answer has the same diagram I feel I have worked from (except different colour scheme).

Edit
Per Tester's answer, and if the diagram is wrong do I need to move one of the browns over?

One of the brown wires will bring power to this point, another will go to the switch, and the final brown wire continues on to the next light.  The markered blue wire brings power back from the switch, when the switch is in the ON position.
You need to connect the brown that has constant power, to the brown that goes to the switch. Next connect the markered blue to the light, and to the brown wire that leads to the other lights on the circuit.
The green/yellow, and blue wires in your image are connected properly.
As you currently have it wired, you have the wire that feeds the other lights connected to constant power. So they will always be on.
Locating the hot
WARNING:
This procedure should only be carried out by persons with the proper tools and knowledge. And should be carried out with extreme caution.

Turn off the power to the circuit at the breaker/fuse box.
Disconnect all brown wires, and position them so that they are not, and will not come into contact with any other wire or metal object.
Turn the power back on at the breaker.
Using a multi-/voltage meter, touch one probe to the "neutral" wire block (where the blue neutral wires are connected).
Touch the other probe to each brown wire in turn.
If you get a voltage reading, mark that wire in some way.
Turn the power back off at the breaker/fuse box.

You should have gotten a voltage reading on only one of the brown wires.
WARNING:
If you got a voltage reading on more than one wire, STOP, do not follow the rest of these instructions. contact a local Electrician.
Now that you know which wire is the power wire, it's time to locate the switch wire.
Locating the switch wire

Find the blue wire that is marked as a switched hot wire.
Follow the wire back to where it exits the cable sheath.
Mark the brown wire that comes from the same cable sheath.

The brown wire that is part of the same cable as the marked wire is the switch wire.
Making the connections

Connect the brown hot wire to the brown switch wire.
Connect the blue markered wire to the remaining brown wire, and to the light.


After I soundproof my bedroom wall with QuietRock, will I need to somehow soundproof the floor? I am planning to put up a layer of QuietRock on top of existing drywall, potentially with Green Glue between the layers for good measure.  I am doing this because the wall in question is against my neighbor's bedroom wall and these condo walls are thin.  Since I am going to be relocating my computer's subwoofer to my room after the job, I am probably going to need some sort of sound absorption for the subfloor.  Since my room is on the second floor, bass is most likely going to travel along the floor and under the QuietRock, thus defeating the purpose.  If it were on a concrete slab, I probably wouldn't have any worries.

Would mass-loaded vinyl do the trick in dampening floor vibrations from a subwoofer?

Edit: I suggest the vinyl because I am not as concerned about bass waves traveling through the floor since both of our garages are directly beneath us.  It would seem that the vinyl would work in keeping waves traveling horizontally under the drywall.  Knowing what to do here will determine the order in which I proceed.

For insulating against sound between floors in our condo builds, we use the following from top down:

Carpeting where possible
Homasote on top of the subfloor
Fiberglass insulation in the ceiling
Resiliant channel to hold the drywall ceiling off of the joists (also known as sound attenuation channel)
Standard drywall ceiling, installed with 1" tight threaded drywall screws into the resiliant channel

I think the part you're looking for is the Homasote. If you have access to, and were concerned with, the ceiling below (which from your comments on the garage, this doesn't seem to be the case), consider the resiliant channel.


How can I support the bottom of a long, open cabinet? My cabinet vendor installed a really cool 5 sided, 12" deep cubby(shelf) below my upper cabinets. It's laminated 3/4" plywood. The problem is that it's 84 inches long and there already is a very slight sag in the middle and I haven't even stacked anything in it yet.

One option my vendor suggested is to put a couple of floating braces underneath it (like this but less heavy duty. I've found some that are 3/6" thick). The part attached to the studs would be buried beneath the drywall/backsplash. The problems is that the supporting arms beneath the cubby would be visible from a number of angles. (My architecture and interior design is modern and streamlined.)

I asked if the cubby could be notched on the bottom so the arm would be flush and then have laminate adhered to the arm to make it less visible. They said that it wouldn't be possible. But based on all of their suggestions it seemed like they just wanted to go with the most simple solution available.

Given my specs would my notching solution be feasible?

I like the open look but to tell the truth you will need some (probably 2 or more brackets) this method, or some decorative dowels that can lift the load.

I have done similar and ended up drilling the center of the dowel and using 1/4” all thread with washers and nuts above and below. to hide the all thread at the bottom I found some brass loops to screw on the bottom end. (Think ceiling toggle bolt but very high end).

The dowels still make the space appear open you could even use a small chunk of the same wood the box is made of 3/4” square x 12” and drill that out and use all thread.

I did try screwing directly into the dowel but with a load (cook books) the screws started pulling out. After adding the all thread it was strong but I needed to hide the nut (I only had counter sank the holes enough for the screw heads and did not want to weaken the area further so the nut and a little of the all thread were exposed, the loops worked out great, if you wanted to reduce clutter a small ball or other type of device could be screwed on to hide the nut and threads.


knee wall no venting possible My master bedroom is above my garage.  There is one part of the bedroom that has a cathedral ceiling with knee walls on both sides.  There is no attic above this area because the drywall goes up along the ceiling joists. This ceiling is insulated with R19 insulation.  The 2 knee walls are formed from the sloping roof in this area.

I also have a fairly narrow front porch that runs the length of the house.  The porch has a roof that creates a knee-wall area along the 2 bedrooms at the front of the house.  This area attaches to one of the knee wall areas in my bedroom.

There is no ventilation in any of these knee walls areas.  There are no soffit vents (or porch ceiling vents in the front porch roof), and there is no way to run any type of venting up to the main attic or to the roof since there is no attic in these areas.  There is no way for me to install gable vents, either.

I have insulation along the back of the interior walls in these areas, but I plan to replace it with a higher R-value insulation.  Should I insulate the soffit areas (and the front porch roof area), and should I insulate the ceiling joists in these areas, as well?

Any help regarding insulation in these areas would be appreciated.  There is no way to run any ventilation, though.

Edit in response to answers:

Yes, I could add soffit vents for intake in these areas, but there is no way to access the attic for out-take venting. Adding roof vents in the areas would look strange and unsightly from the front of the house as these areas run on both sides of my bedroom window which faces the front of the house. Adding a roof vent to the roof area of the front porch would also look very strange and unsightly from the front of the house. The same is true for gable vents. I would have 2 gable vents on the sides of my bedroom window at the front of the house, and, they would only end up being about a foot off of the floor in these storage areas.

So, should I insulate the ceiling joists and soffits in these areas, or should I just insulate the back of the knee wall?

I'm having trouble visualizing the whole layout. That said I also have knee walls and sloped ceilings. I was able to force attic baffle vents between the insulation and roof by taping them together, then pushing them up with 1x2 sticks. It's not perfect I'm sure, but does allow some ventilation from behind the kneewall to the main attic. Of course, I have soffit vents at the top plate behind the kneewall and a standard ridge vents at the top of the roof.

If you really can't add soffit or ridge vents maybe consider making it a hot roof and add more insulation on the actual slope ceiling/roof, either interior or exterior (if a new roof is in order anytime soon)


Is a 2x4 strong enough to hold up a porch swing? I'm hanging a porch swing, but the beams run the wrong direction for the support hooks.  I've looked up in the attic, and there's a 2x4, lying flat, that runs the correct direction.  Will that be strong enough to support, say, 500 lbs?  Due to the angle of my roof, I can't actually reach the board so there's no hope of supporting it from above.

There's really nothing stopping me from getting a different style of support hook (one that drills into the wood at a single spot instead of two), but if possible, I'd like to use what I've got.

There are several issues to consider - whether the 2x4 itself is strong enough to bear the load you're putting on it in the direction that you're loading it (so the grade/type of wood is important, not all 2x4's are created equal), whether the fastener/hook you use will overstress the wood in the 2x4 at the point where it attaches, and whether the load on the 2x4 will overstress/exceed the capacity of whatever it is that's attaching the 2x4 to whatever it is that it's attached to/supported by.

My unscientific, short answer is "no", I wouldn't depend on a 2x4 of unknown provenance to support the weight of 2 adults (or any number of children) + the weight of the swing, especially given wear & degradation over time.

If it was a short run of 2x4 and the swing was attached really well and the 2x4 is attached really well to something strong, yeah, it'll probably work, but if it were my house/family involved, I'd look for a stronger way to hang the swing.


How can I prevent water from remaining in a flexible shower hose? installing a handheld shower over tub, all new plumbing.  diverter valve on tub spout.  pressure-balancing control and no fixed shower head.

I want to make sure water will not sit in the handheld hose between uses.  It seems that it should siphon out thru the tub spout when the flow is turned off, please confirm?

i would have to disagree with daniel above.  standing water leads to mineral deposition and galvanic corrosion much faster, and in places it may not normally happen.  pathogenically, you could also be hosting lots of little bacteria and fungii in that standing water, particularly on a well water connection.  hand wands sometimes go months between uses, so i think you are probably right in trying to avoid this.

in these installations, it depends on a few things:

1)  loops in the wand hose will hold the most water.

2)  some wands have a backflow valve in them,  this will prevent any break in the column and could leave water in a hose no matter what you do.

3)  some tub diverters don't open properly on stop of water.   they pop open when the pressure comes on again, but dont necessarily release when the water flow stops.  that could hold water above them.

4)  some thermostatic mixing valves (like the moen 3285 and 3210) are notorious for not letting water flow back through them freely or predictably.  this is just the valve design and cant be worked around.


Is it possible to collect rain water from a roof for drinking use? For a re-roofing or new build, I was pondering the possibility of capturing and purifying water for drinking use.  Are there good examples of this?  What roofing materials should be used or avoided?

This could be relaxed to vegetable gardening gray water, so long as the roofing material didn't introduce something that would end up in the produce (unless it was practical to filter out before reaching the produce).

It turns out people have consumed rainwater for millions of years. So there's some precedent.

This is very well covered online, so grab a search engine and get reading. Here's a summary of concerns.

In the US, it may be illegal (look up "water rights") but for individual home use, that is usually ignored.

You'll get a lot of water from your roof really fast. It's pretty amazing.

The biggest problem is the dirt on your roof. The rainwater coming down is great, but once it hits your roof, it's dirty. You can redirect the first bit of rain, and then collect once the roof is clean(ish).

The roof material matters. Some roofs will leach small amounts of toxins in to the water that you probably don't want to drink. Metal is probably the best choice for a roofing material.

For most homes, only a small portion of the water goes to drinking. Much of it goes to laundry and flushing toilets and irrigation. These systems don't mind slightly dirty water (including greywater). Use your collected rainwater there first. You can haul it by bucket or plumb something special.

A problem specific to collecting rainwater for irrigation is that it always comes at the wrong time. You would have to save it from the wet season to use in the dry season, which implies a huge cistern. Being clever helps. For example, a cistern can go under a deck.

Any water storage should be protected against mosquitoes. You can put fine mesh screens over openings, or (my favorite) put goldfish in the tanks to eat the larvae.

Cleaning dirty water to be drinkable is harder. If you build a complex filtration system, you'll probably negate all the financial and ecological benefits of saving that small amount of water you were drinking. My favorite approach is the slow sand filter - it's simple, cheap, low energy, but it takes a lot of work. read here: http://www.homestead.org/TedPraast/SandFilter/Filter.htm


How should I replace a tub spout? I am also having trouble with water still coming out the spout when the shower is on. When I replace the spout should I use Teflon tape (it has a set screw) and plumbers putty between the spout and shower wall?

If I remember right, the kind with a set screw have a rubber grommet and don't need tape (if there is a threaded connection then you should use some).

Use clear silicone where it meets the wall and leave a tiny gap at the bottom for drainage.


how to fix rotten exterior wall Due to moisture my outside wall is rotten in a small section of house. Picture attached. What is the best way to fix this.

I see that you have posted two questions about this situation. I fear you have to address a couple of problems here.  First and foremost is to try to route water away from this area. We can address this in another segment with more info on the area in question.

As far as the immediate problem, I am pretty sure you will have to remove the damaged sections of the rotted siding. I also suspect there will be damage to the bottom plate and will have to be replaced as well. Also inspect any insulation in this wall for moisture damage and mold.  I would be looking at replacing the sill plate with pressure treated lumber and seal it with caulk under the plate to avoid any water creeping indoors under the plate.  If you do not want to replace the entire height of the siding, you may be able to scab a matching replacement patch in there, but that could be unattractive.  You could install a horizontal trim piece along the bottom, under cut or flashed to the siding if the rotted section is not too high up the wall. The important thing here is to remove the rot and create a side wall that will not rot again. You could use a PVC trim board (1X8 etc) or other rot resistant material. This is one of those jobs that require a look-see and adapt a solution as the amount of damage is determined. If you are looking for step by step directions for cutting, removing, and replacing, that is a whole other discussion, depending  on your level of expertise and tools you have available.


Is heat a practical way to kill structual mold? So heating the whole house or affected rooms up to 45 50 degrees C for long enough to also heat and kill any mold in exterior walls as well as mold on the surface?

I have to agree with Solar Mike. Sure, it might kill existing mold, by drying everything. But, it will reactivate if its cause isn't addressed...you may just need to run the air conditioner or exhaust fans more often or plug-in a dehumidifier.

Although, is there a concern? Not really. Mold is literally everywhere and in every breath you take and run-of-the-mill mold concealed in walls has no effect on people nor building products.

Now, if you mean Black Mold that's even showing up inside rooms in little patches. Then, you really MUST rip out the walls and professionally remediate it from the property.

Black Mold is EXTREMELY serious and also means you have a very blatant construction problem or water leak that's been ignored too long. In order to avoid PERMANENT health problems the issue(s) must be fixed entirely and ASAP.


Vacuum belt sliding off of rotator I have an upright vacuum cleaner with rotating brushes at the intake. What rotates them is a belt that is rotated by a small rotating divot-looking thing.

The belt is always falling off of that divot.

The divot used to be silver/steel-colored, but is now brassy. I suspect, therefore, that it got smoothed out by use, and the smoothness is making the belt slide off of it. Does that seem reasonable? Can anyone suggest another explanation?

But what I really seek is a remedy to the belt-sliding-off-the-divot situation. (If the problem is smoothness of the divot, then perhaps a way to roughen it up.)

You're absolutely right & that's what's happening...unless of course you have the wrong belt. It's time to buy a whole new Rotator thanks to planned obsolescence.

Although, I might be willing to try some sort of retainer until the new Rotator arrives. Maybe 3 screws on either side of the belt area around the rotator body & far enough away as to not saw through the belt. Or, band clamps holding thicker plastic strips (sides of plastic lids or layers of soda bottle bodies) around the rotator body. A screw on guide or retainer where the belt comes out to the rotator...nothing on the rotator so you don't spend 3-days balancing out. You get the idea.


Is it normal to have a light switch setup using only the hot wire? I was changing the light switches around the house when I came upon this setup.

The two switches to the right are all wired using the hot wire (black) from the two electrical wires on the back panel. All neutral wires (white) are tied together and are left unused.

I am no expert and not even an amateur, but I find this setup strange.

If I change the light switches, should I follow the same connection setup in the picture or try using a standard black-white setup?

The switch on the left (not visible) is a three-way switch.

Yes, this is normal.  There are two ways to wire a two-way switch with 2-core cable like you have:

one where the switch is between the supply and the light fixture(s).  This is how your switches are wired.

As you can see from the diagram, the white wire is used -- it completes the circuit back to the electrical supply's neutral line.
one where the light fixture is between the supply and the switch.  I think this is what you mean by a "standard black-white setup".

Note that the white wire in this case must be marked to indicate that it is carrying the electrical live; I use a small piece of black electrical tape wrapped around the insulation.  It's common (in my experience with amateur wiring at least) for this step to be omitted.

(Images found here)

If you change the switches, you should follow the original wiring.


How to Wire 3 baseboard Heaters with 2 Thermostats I have one 20 amp double pole circuit that I am planning to run 3 baseboard heaters on with 2 line voltage thermostats. I have already made sure the watt consumption for the 3 heaters will not exceed 3,840 watts. I have run 12/2 wiring from the breaker to the first thermostat location which will control 2 baseboard heaters and from there to the other thermostat which will control the 3rd heater. I have uploaded a quick diagram for visual reference. I believe I know how to correctly wire this up but just want a sanity check before committing. I believe I can just pig tail at thermostat 1 to pass power through to the second thermostat location (bedroom) and for the thermostat that controls two baseboard heaters, it seems like the wiring is simple.  Any help is appreciated!

You are correct -- just don't overstuff the box!

Pigtailing the wires to room 2 with the line-side of thermostat 1 will get you what you are after here.  However, with the thermostat and the 3 12/2s in there, that's too much stuff for many single gang boxes (20.25 in3 of box fill vs the largest standard device box in the Code being 18in3), so you'll want to use a bigger box such as a 4" square with a single gang cover/mudring there instead.  You'll also want to wrap each of the white wires in this with black tape to make it clear that they're hots, not neutrals.


Preventing a door from slowly opening itself This is pretty simple but I don't know how to describe it. There's a door that if left open half way it opens all the way by itself. I'm not sure if it's on an angle and gravity is doing it. How do I make it so the door stays where it is and doesn't open all the way? It's on 3 hinges and is on the inside of the building.

It is indeed gravity.  You can verify this with a accurate level (test your level by putting against the hinge side door jamb, noting the bubble position.  Then invert the level (put the opposite face against the jamb and you should get the same bubble offset) The jamb frame is likely canted.  Fixing a canted jamb is very involved: removing door, trim casing from both sides, removing shims and reinstalling new ones.

Fortunately, there is a quick-and-dirty fix for doors that are lightly canted: Cause a hinge to bind (slightly).  This will allow the door to 'stick' in position.  Try this on one hinge at a time (I like to start at the middle (of 3), so that the door stays in place.  Remove the hinge pin, remove the door side leaf.  Using a adjustable wrench, adjust the wrench to clamp over one loop (of the (still in place) jamb side hinge).  Pry that loop a bit out of alignment.  Replace the door side leaf and pin (it should be a little tight). Test door.  Readjust as needed (too tight or not tight enough)  Other loops of the door side hinge can be similarly adjusted.

If your jamb side screws are marginal, (they move while prying) you should replace them with longer ones, especially on the center screw (of the 3).  A 2 1/2 inch screw will lock down the hinge to the internal framing.

Alternatively, if you have access to a vice, you can bend one loop of a removed hinge leaf.

Finally, if you have enough door gap at the hinge side and its clear to you which way to tilt the door (from your level check), you can correct its 'lean' by 'tipping' the door back (towards) vertical by bending ALL the loops of the jamb side of the hinge away from the door.  This will reduce the door-to-jamb gap.  You would typically do this to only a top or bottom hinge (to reverse the tilt)


Why is my two month old dishwasher exuding a terrible smell? In July I purchased a new Whirlpool Gold Series dishwasher model WDF750SAYW1. The machine has done a great job cleaning dishes, but it recently has begun to emit a terrible smell. The odor is not that of plates waiting to be washed. The smell is more akin to that of rotting garbage. I have cleaned out the upper and lower filter assembly though neither had any trapped food. As expected there was a small amount of standing water underneath the filters.

After running the dishwasher the smell is gone. We run the dishwasher a minimum of four times a week. For seven years we never had a problem with the previous dishwasher (its control panel died necessitating the need for the replacement).

Here are some pictures of the hookup:

What should I be doing to fix this terrible odor? Is this a plumbing issue or something wrong with the machine?

Modern water saving appliances seem to be prone to this. Usually using proper detergent keeps this in check. Since the smell goes away after a wash, it sounds like you are doing this. You might try a different detergent anyway. It may also be a plumbing issue if standing water is consistently left at the end of the cycle.

Unless you're on a septic tank, start a empty wash cycle and let it fill with water. As soon as the water starts circulating, add 1 cup of household liquid bleach. Use 1 pint white vinegar if on a septic tank. Close the door and let the water circulate for 10 seconds, then stop the cycle and let it sit for 1 hour. Restart and finish the cycle.

Clean the filter and screen with hot soapy water. This should get rid of the smell, but it will eventually return.

Clean the filter and screen on a regular basis, perhaps weekly. When the smell returns, redo the bleach treatment.


Safety concerns and precautions in setting up a workshop/studio in the utility room I am considering setting up a workspace/studio in my utility room in the basement, which has a hot water tank and two furnaces. Here are the warnings on those units.

Hot water tank:

Furnaces:

I wonder if this is a good idea in general to set up a workspace in the utility room. Is it a risky move? Any advice, safety concerns or precautions should be considered or put in place? For example, I am thinking about adding a carbon monoxide detector in the utility room to give an earlier warning in case of CO leak.

Edit:
I am planning to use it for, say, art projects, building model gundam figures etc, and/or building robotic projects. I am also open to suggestion of what this room should be used for if those projects put it in higher risk. I just want to better use the space if possible.

I don't see any cause for concern with your intended use of the area. However, things don't always work out like we plan.

Therefore, a double-the-capacity Bath Exhaust Fan, Exterior Wall Fan or even a kitchen Range-hood (to be down much closer to your work...can be mounted to slide up and down) would be ideal.

Such an exhaust can be switched on and off only as needed and can act quickly to the demand. The installation of an Exhaust Fan intends to flow clean air past the furnaces and water heater as your fumes and dust exit the house while never coming near those appliances.

Yes, an Exhaust Fan can create a negative pressure scenario that could possibly draw CO from those appliances, but most homes leak enough air for that not to happen. Just keep your workspace Exhaust Fan, if you choose to install one, within a finite ability.


Secondary Generator Wiring I have a Generac Guardian 22kw hardwired in via an RTS switch. When the power goes out (and it does so fairly often) the generator kicks on automatically and there is barely a flicker in the lights.
However I am all about redundancy. I also have a 15kw "portable" generations that I would like to be able to use as a backup to my backup should the 22kw go down during a blizzard or something. I have several 50amp welding and RV plugs. Could I wire up an inlet box and provide power that way? As long as the RTS switch is flipped and keeping it shut off from the main power line that should be fine right? Am I missing anything? Thanks!

The trouble with back-feeding portable generator power through any of those welding or RV plugs while the transfer switch is set to generator position is the same problem with relying on turning off the main breaker before doing the same: it's manual, not interlocked, and sooner or later somebody is going to get it wrong.
Instead, daisy-chain another transfer switch. It could be another RTS series switch if you're so inclined, but the transfer switch could also be as simple and inexpensive as a main-breaker type panel with a generator interlock kit for a branch breaker.
I gather you'll want to keep the automatic switch-over for the 22 kW generator working and add a manual alternative in case the 22 kW breaks down or you just decide not to use it. To do that, add a 150A or 200A main-breaker panel. Wire the main breaker to the 22 kW generator. Add a branch breaker in the 100A-150A range and wire that to the "generator input" connection of the existing transfer switch. Finally, add a 70-100A branch breaker in the designated "generator backfeed" location of the panel and wire this to an inlet socket.
With the above arrangement there are two operating modes. Either the main breaker is on, allowing 22 kW generator to connect to RTS input, or else the generator interlock is activated so that the inlet for the portable generator is connected to the RTS input.


What tool to tighten this nut? This is on a valve for a fancy walk in tub.  The nut tightens it against the top of the tub to hold it in place.

But I have no idea what this kind of nut is called, nor what tool to use to properly tighten it.  I can get it kind of tight using vice grips, normal wrenches, and hammering it with a flat head screwdriver.

Some of them are about 2 inches in diameter, others 2.5-3 inches.

But surely there is a proper tool for this?  What's it called?

Although you can nearly always use something from a normal toolbox, a hook spanner is ideal. One of the top two in this image would work (the third is a pin spanner):


How do I separate two 3-way switches to control lights separately? I have a porch light and three outside lights, along the garage, controlled by two three-way switches.

One switch is inside by the front door and I would like this one to control the front porch light. The other switch is in the garage and I would like for this one to control the lights along the garage.

The house is only two years old. Can you help me with a fix for this?

In the most basic way it would depend how the wires were fed between the lights and the boxes. There are many combinations so we would need to see a diagram of were the wires go.

So you would need to do a drawing and post it. If you do that somebody would be happy to draw ontop of it for you and connect your wires if it can be done. (Do not worry about drawing the grounds, we will assume all your boxes have them).
To test where they all go you would need to

TURN off your circuit and test that it's off.

Than you would need to open all your boxes and open all the wire nuts except the grounds. Leave them connected. And make sure no wires are touching each other.
Now you need to set your meter to the low ohms (omega symbol) OR continuity setting (looks like 3 lines ontop of each other projecting sound).
Now you may go around from box to box piecing together where the wires go.  Go into the first box and attach a red or black wire to a ground (have them touching) and with your meter in the second box put one lead of your meter on any black or red wire and one lead on a ground (all the grounds are connected so any one is fine).

All multimeters are different but some multi meters have a continuity function , where it beeps if there is continuity. Basically it beeps if those are the correct wires and current can travel that path around the meter. Meaning that is the same wire/ same cable on whatever two wires your meter is on. If there is no continuity it will not beep.
Other meters to show there is continuity will have a very low ohms reading. If it wasn't a match it would have an infinity number or OL.

Once a wire from each cable is tested, record those findings and make a drawing. You will not have to say where each wire connects on the drawing (we more care where each cable runs to and how many wires). But maybe you want to draw that so you can put it back together!

We will also need to know which cable is the home run/ hot power cable.
To test that with all the cables still NOT touching (except grounds with each other) you will need to flip the circuit breaker on. And very carefully with your meter on Volts AC go between what you think is a hot (either black or red) and a ground and see if you have 120V. If you do. Thats the home run and record it on the drawing. That is an important step to let us know that. Don't forget to write which boxes are switches and outside lights etc... Good luck.


According to NEC 210.52 can this receptacle be counted as part of the required outlets in a dwelling? Under NEC code artcile 210.52 Dwelling Unit Receptacle Outlets

...The receptacles required by this section shall be in addition to any receptacle that is:

(1) Part of a luminaire or appliance, or

(2) Controlled by a wall switch in accordance with 210.70( A) (1), Exception No. 1, or

(3) Located within cabinets or cupboards, or

(4) Located more than 1.7 m (5 ½ ft) above the floor

So my question is if I have a half switched outlet at 60" that is behind a painting, is that counted as part of the required outlets in a dwelling since it is less than 5 1/2 ft?

It can be counted as a required receptacle since it does meet the letter of the code.


How do I identify the C terminal on my HVAC? How do I identify the C terminal on an HVAC, furnace, or boiler? If the terminals don't have a screw labeled C what should I look for on the wiring diagram? What steps should I take if a wiring diagram cannot be found or if it indicates that a C terminal doesn't exist?

Note: This is an extension to How can I add a “C” wire to my thermostat which asks about running the wires through the wall. This question is about where to connect the wire at the HVAC.

Wiring Diagrams
Locate the schematic
In most cases, a wiring diagram can be located inside the HVAC unit. Typically, it will be on the inside of the access cover.
Find the transformer on the schematic
Once you've located the diagram, you'll want to look for this symbol.

Or the actual text that says "Transformer", which may be labeling a crudely drawn transformer, or simply a rectangle.
Primary or secondary?
After finding the transformer in the diagram, you'll have to determine which wires are connected to the primary coil, and which are connected to the secondary coil.  Check the diagram for a key, which will give you a hint.  On some diagrams a thicker (bold) line denotes line voltage wiring, while a thinner line represents low voltage wiring. Others may list the voltage and frequency on each side of the transformer.
Trace the wires
Now that you know where the transformer is on the diagram, and which side is the secondary. The next step is to follow the lines, and see where they go.

In this example diagram, you can see that one leg of the secondary connects to the R terminal on the control board, and the other leg connects to the C terminal.  In this example there's actually a C terminal present, but that will not always be the case (especially in old models). However, even if there isn't a dedicated C terminal, that doesn't change what the C wire is.  Which is simply the other side of the secondary coil.
In Real Life
Now that you've located the transformer in the diagram, or maybe you don't have a diagram.  Either way, you'll have to locate the actual transformer inside the HVAC unit. You'll be looking for something that looks similar to this...

Honeywell 24V AT72D Transformer

An action shot of the actual transformer in my furnace
Primary or secondary?
Once again, you'll have to determine which is the primary wiring and which is the secondary.  If you had a wiring diagram with the wire colors labeled, this is simple.  If you don't, you'll have to figure it out.
Wire color
In the US, typically the ungrounded (hot) conductor will be black, and the grounded (neutral) conductor will be white.  It's common for this color code to follow through to the primary side of the transformer, so a set of black and white wires is likely the primary side.  The secondary could be any color, though commonly the R wire will be red.
Wire size
You may also be able to determine which is which, based on the size of the wires connected.  The primary wires will typically be either 12 AWG or 14 AWG, whereas the secondary may be smaller.
Measure.
If all else fails, pull out your voltage meter an measure.  The primary side will be line voltage, and the secondary will be low voltage (commonly around 24V).
Trace the wires
Now that you know which wires are connected to the secondary coil, simply follow them to their termination.  One of the wires will be connected to the R terminal, the other may or may not be connected to a terminal that is labeled.  But even if it's not labeled, it's still C.

Transformer connected to two wire, heat only thermostat.

Transformer connected to three wire, heat only, WiFi thermostat.
For more information on transformers and C wires, please see More than you've ever wanted to know about the C wire


Analog multimeter won't calibrate to zero I have a multimeter that I haven't used in many years.  I wanted to recalibrate it, so I touched the two probes and tried to adjust the reading to zero, but 500 ohms was as low as it would go.  Is the meter bad?

I assume, since it has a zero-ohms adjustment at all, that this is an analog multimeter (one with a physical moving needle). In which case, you should try replacing the internal batteries. They are used only in resistance mode (so everything else will work), and if they are weak they will not be able to produce enough current to move the needle to full scale, which is what you are seeing.

Many meters do not have separate battery compartment doors. If you do not see one, try removing the entire back cover (if there are obvious screws with which to do so). You may also find fuses, which would need to be replaced if the current mode of the meter is not working.

The above advice is for the zero ohms point which is at the far-right end of the scale. The left-end zero in other modes — where the needle rests when no connection is made — should be adjusted using the screw or knob on the face of the meter at the pivot point of the needle. This is a mechanical adjustment of the return spring. If turning it has no effect, then the meter may be damaged, or the linkage between the adjustment screw and internal parts may have become disconnected in which case careful disassembly and reassembly may fix it.