Best way to get both 120V and 220V from existing multiwire branch circuit (MWBC) I have a double pole 20A breaker feeding a 120V MWBC with 12/3 with ground, romex that goes up three levels to two separate 120V duplex GFCI receptacles with common neutral.

I want to have both 120V and 220V small appliances.  Wanting to add a 220V 6 amp coffee maker to two small 120V appliances. This is not a kitchen, but indoors, off of a top deck. The MWBC feeds just the two 120V duplex GFCI's, nothing else.

What is best practice to do this?

I could run existing MWBC wires to a small panel, then install one double pole 15A 220V GFCI breaker and two single pole 15A 120V GFCI breakers, and new receptacles. Possible also to use the existing 120V GFCI receptacles and regular single pole breakers fed off this panel too, in this situation.

Or could leave the current two GFCI receptacles alone and take 12g wire pig-tailed from the ends of the MWBC to a 'spa' panel, change out the breaker in the 'spa' panel for a 15A or 20A 220V double pole GFCI breaker and then connect a 220V receptacle.

Or I could attach an inline 220V GFCI to the hot leads of the MWBC in a junction box.

Or I could use a 2000W step up/down transformer plugged into one of the 120V GFCI receptacles. It just seems redundant to convert the voltage when I already have it there, but a plug-in transformer may be the most code compliant and cheapest, way.

I can not run another wire from my main panel. I cannot replace the 20A double pole breaker in the main panel, with a GFCI breaker, as it is actually a quad breaker.

Any other ideas? Other than code won't allow any of it? Wife really wants the coffee maker so it is going to get done somehow.

You do not have a "120V MWBC".

You have a plain MWBC.  240V-only (no neutral) loads are allowed on MWBCs.

They even make receptacles for that.

Note how there is no tab to break away on the visible side, since one must be neutral and the other L2.  However you can see the tab peeking out from the other side, which could both be L1 of the same circuit.. Because this is legal on MWBCs.

As far as GFCI protection:  It's an easy job for a 2-pole GFCI breaker.  Replace the current non-GFCI 2-pole breaker in the service panel  with a 2-pole GFCI breaker.  Liberate the two GFCI receptacles and reuse them somewhere useful.

If you don't have space in your panel, then it's time to fit a subpanel somewhere. Since you're ready to do that, do that... just not out at the patio where it'll be a one-trick pony.  Next to the main service is better. After all, you have this "out of spaces" problem all over your house.  So fit it somewhere that makes sense for all your future loads.

I know adding a subpanel is a big job, "best" kicked on down the road for awhile longer... But the fact is you'll be right back here again when the wife wants an on-demand water heater or a plug-in hybrid.  In this day and age, with so many amazing electrical gadgets, a full panel is no place to be.


Checking ground current Background:
I had a contractor finishing my basement, and part of that was installing underfloor heating using several heating mats in parallel.  It worked initially but soon after it just started tripping on a ground fault (built in to thermostat).  I think my contractor is a little out of his element so I took some time to try diagnose the issue.

There are no obvious issues in terms of element resistance or total current draw, so I started to check for ground leakage.  I don't have a megger and so I used my DMM to check resistance to ground for each element, nothing measurable.

Here is my question:
As a more detailed check for leakage to ground I used my DMM to measure the current.  For each mat I DISCONNECTED the neutral side, connected one lead of my DMM to the hot side of an element and then touched the other lead to a hot wire (not from thermostat).  So in theory this should just measure current leaking from the element to ground, right?

I ended up measuring between 4-8 ma for each element.  Seems a little high if this was correct.

GFCI's are set to trip between 4-6ma of leakage current. This is a pretty sensitive setting to measure.

It is possible the GFCI in the thermostat has gone bad. Like all electronics, it is prone to failure at some point.

I would try a new thermostat to see if it holds. If not, you need to investigate the wiring further.

Good luck!


How do I screw two posts together so that they look seamless and can easily be taken apart and put back together? I would appreciate help so much!

I am trying to make a 'collapsible' arbor if you will. I would ideally like to saw my large birch posts in half and make them screw back together in the center, but I have no idea how the mechanics of such a thing would work. Double headed large screws!? Any suggestions would be appreciated.

The birch posts in the original design were made a certain length to serve a particular function. I am sure they were selected on the basis of strength, stability, and durability. As a first order analysis the idea to cut them in half seems to defeat almost all the reasons that they were designed for in the first place.

It will not be possible to simply cut the posts in half and re-join them in a manner that will restore them 100% back to the original look and function. That said there may be some ways to come close to that as possible if one can look past the cut lines and some fasteners / bolts.

There is some missing information that will be needed to provide the overall solution and/or suggestions. I can provide one possible idea for the case where these posts are deployed in a vertical orientation and the girth of the post is substantial.

The idea is to go ahead and cut the post in half and then install a heavy piece of steel pipe into a hole drilled into each end of the post. The pipe would be glued into the lower hole using construction grade adhesive. Cross holes would be drilled though the sides of the upper post to accept bolts that would be threaded into prepared holes on the other end of the steel pipe. See picture below:


How do I pre-wire for in-ceiling speakers and give a clean finished look without installing speakers for several months? I am building a new home and I would like to pre-wire for in-ceiling speakers. I have seen in some newer homes small plastic plugs in the ceiling where the wire is located. This allows the home owner to install the speakers at a later date, while still providing a nice clean finished look without a large cover; the plug is about the size of a silver dollar.

Does anyone know what these plugs are called and where I can purchase something like this?

There are low voltage boxes used for stereo equipment that may suit.

These can be covered by blank plates that are then painted to match the ceiling. When you are ready, remove the cover and either attach the device and wire through the box or cut a larger hole for the device.

As an Alternative, you could use a bushing like this, and wedge/glue the wires inside the tube

Then you can fill the center hole with taping compound or spackle. When you are ready, pull the bushing down with the wires attached.


Vapour barrier for basement garage ceiling To make the floor of a bedroom above a garage warmer it is desireable to insulate the garage ceiling.  Does a vapour barrier go up in the joists against the floor above since the house would be expected to be the warm side or between the gyproc and insulation on the garage side since engine heat and meling snow might create a temporary humidity problem?  This is near Calgary where the air, on average, is relatively dry.

The vapor barrier goes towards the heated size of the home, which in your case will be up between the joists against the floor.


What fastener should I use to attach an aluminium bracket to a wall? Is it OK to use a regular zinc plated screw when fastening an aluminum bracket to a wall?

It might seem like a silly question but I have heard that mixing metals in fastening applications can result in corrosion.

UPDATE: It seems like corrosion is only a factor when dissimilar metals are used if moisture is present. For example boats. Otherwise dissimilar metals won't react. Someone said that zinc is actually a better choice than stainless for this application. I will keep my question here but I thought I would add this update based on my latest research.

Should be fine, especially for indoor use, where there is little moisture and salt. Zinc and aluminum are pretty close galvanically, so the zinc coating should help. In fact, most bolts used on aluminum-structure airplanes are made of steel plated with zinc or cadmium (source).


Copper Ptrap snapped during bathroom demo, how to fix? Trying to demo my bathroom for a remodel, had the P-trap snap because it was corroded. I'm left with what's below. What items do I need to repair this? I imagine I would want some PVC to Copper connector and get a PVC P-trap? But there are so many available: https://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=P-trap I have no clue what to choose.

Also there is a bolt behind that cover in the picture, but it won't budge a centimeter. I assume I would need to remove that part that is broken, but what/how do I replace it? And what should I use to unscrew it since it won't budge a tiny bit trying with pliers.

Better pic behind the cover:

My weak attempt at measuring:

Soak it good with penetrating oil. Then use a pipe wrench if you have one. Righty tighty, lefty loosy. Yes your measurement will work. Most kitchens are 1 1/4" and bathrooms are 1 1/2" however this can be different. Looks like you have 1 1/2". Get a new kit similar to this http://www.homedepot.com/p/Everbilt-1-1-2-in-Plastic-P-Trap-C9704B/205153793 plus any adapters you need that are not in the kit. Some kits have everything you need and more, some only a few necessary parts.


Upstairs Story Not Cooling Despite Working AC? My house has 2 zones for air conditioning (Upstairs & Downstairs) with 2 different air conditioning units.

We have Nest energy saving thermostats, which are great for keeping track of energy history, and I noticed that the downstairs AC is virtually never on, and the upstairs AC is on almost constantly.

This is mysterious to me because we clean our air filters constantly (Including the outdoor AC unit itself (Once per season). NOTE: I live in Suffolk County, New York

Observations:

0) There is cold air coming from the upstairs vents, although it isn't at a very high rate. There are vents downstairs that have far higher (Around 2x) air flow.

1) The thermostat can't reach its set point temperature. This situation lasts through the day (Check History for more on this):

with the upstairs temperature never reaching the set point, and always staying above it. (Note the 80 on the side is the current temperature)

2) The downstairs thermostat is in sync with the upstairs thermostat usually. (They are also both on at the same time) to minimise heat gain die to convection.

AC History:

Upstairs:

Downstairs:

Specifications:

Unfortunately, there are no records of the AC system that I could find, but I did manage to get this from the back label of the AC unit that is always on: C 249534. I don't think I can get more information without actually taking the panel off.

There is also some kind of machinery on the inside (I'm not entirely sure what it is):

Further Away: (The top panels say Ultra 80 & the bottom labels say Armstrong Air

There are also electro-static filters (Which according to my dad contain the only filters in the system, although he might be mistaken, I'm not sure)

Are there any obvious red flags with this set up? What is the most likely cause of failure given the set-up of the system? Are there any additional filters that I didn't know about that aren't being cleaned? Are additional specs required?

It looks like the air handlers are both in the basement.  There will be a fairly significant friction loss due to the added distance of the second story air ducts.  If the ducts weren't carefully sized and balanced from the beginning, this could impede the airflow.

Another factor could be the return air.  If the upper story does not have its own return air, then the returns will be sucking air from upstairs down to the lower floors when the system is on.


Countermeasure for Drain Flys A Florida home was saturated with drain flys.  What is the most effective countermeasure, besides keeping drains filled with water?

I've read that pouring oil, such as vegetable oil, into a drain will put a film on top of the water in the trap and that this will dramatically slow the evaporation of the water. When you anticipate that water won't be run through a drain for a long period of time, you could preemptively add oil to that drain.

This might leave an objectionable ring around the inside of a toilet bowl, but for other drains, maybe it's worth a shot.


Where can I find the AZ county building codes? I need to look up the building codes for counties in Arizona, specifically Maricopa County and Pinal County.

I'm looking to build a custom home out of storage containers and I'd like to first read the building codes if applicable. All my contractors are lined up, I just need to know what is and isn't allowed. Or even if storage container homes are allowed in AZ.

It looks like they are using the 2012 Edition of the International Residential Code (IRC), See here:

https://www.maricopa.gov/2262/Construction-Codes

However, for your application, You want to check the ZONING ORDINANCES rather than the BUILDING CODE. Your county Planning Department can check to see if the area you want to build in is zoned for containers. If they are, they can tell you setbacks, maximum lot coverage, etc.

Also, I’d check the CC&R’s (covenants, conditions and restrictions) for the area you live in. Some CC&R’s don’t even allow dish TV’s exposed to the street. Be careful on what is allowed...


How to permanently join 2 cut Pergo pieces? I want to permanently two Pergo pieces to make a longer piece. Could I simply use wood glue for this?

jut cut a tongue into one and a groove in the other.  glue and you are done


How should I paint an exterior door to prevent sticking? Most quality paints for doors have at least a 5-day full cure time.

So how can I paint an exterior door and keep it from sticking to the stop?

I mean I could obviously paint it first thing in the morning on a warm summer day and leave it open until I want to go to bed but that's not fully cured.

I'm considering removing the door, painting it, boarding up the opening, and going on vacation for a few days.... But there has to be a better way!

Don't paint the portion that will touch the stop
Swap in a spare door for a few days (habitat for humanity re-store has them quite reasonably priced, for instance.)
Do the paint job on a new, or new-to-you used door, and only swap it once.


Is an electric dryer's vent pipe a fire hazard when routed through the floor? I will be venting my electric clothes dryer through a pre-cut hole in the floor.  It will be vented using flexible, foil type tubing and traveling a short distance to an exhaust on the side of my home.  My concern is how hot the dryer venting may get that is almost touching the bare wood hole in the floor.  I haven't found a collar that would fit around the 4 inch tubing and fit the hole, which is around 5 inches.  Could I line the hole with a silver foil duct tape used for HVAC jobs, etc. to protect it against the heat?  Suggestions?

It's not a concern. Dryer exhaust might hit 200 degrees, but most have thermal fuses far below that. You'd need twice that and then some to start a fire. Heck, many dryers are vented through cheap vinyl hose. If it was a concern building codes would require double-wall flues akin to those used for gas appliance exhaust.

I do recommend against the lightweight foil hose, though. It really accumulates lint. Use semi-rigid aluminum pipe at least (example). Its ridges are much smaller and it's less likely to close up on itself in a bend.

You may have heard of the risk of not cleaning the lint filter. This can result in reduced airflow and heat accumulation, but any fire is likely to begin in the dryer in this case. More on that


Adding Undersized Fuse to Doorbell Circuit? So recently my doorbell button got stuck and it burnt out both the electromagnetic coil in the chime and the transformer. As I'm replacing everything I was thinking that I could add fuse to prevent a rogue button from causing so much damage again.

The transformer is 16VAC 10W and I measured the voltage as just over 20VAC. The chime consists of an electromagnetic coil that drives a pin hitting a chime (separate coils for the front and back buttons). It claims it's suitable for a 16VAC 10W or 16VAC 15W transformer.

Let's say that x amps run through the circuit when the button is depressed. Normally the button is depressed for very short periods of time (let's say <10 seconds for an enthusiastic doorbell ringer). I've read that a fuse can withstand more than its rated current for a period of time depending of how high the current is over the rated current... can I undersize a fuse such that the blow time for an x amp load would be 10–15 seconds? Would sizing the fuse be so finicky as to be not worth it?

Wouldn't a slow-blow fuse work? I don't think you'd want to under size it. Just understand what voltage/current ratings you need and find a slow-blow fuse that can handle 10-15 seconds of that.

Something like this. Just figure out where you need to be on the Average Time Current Curves.


Unwanted grounding from metal screws in metal boxes In the winter I repeatedly get intense static discharge shocks from the faceplate screws in my basement light switch panels (which are grounded metal boxes, unlike the plastic ones used in non-basement locations). Is there any good reason not to replace the screws holding the faceplates on with non-conductive ones? Are matching (size and thread) plastic screws available? Or is there some other clever solution to the problem that's not ugly or dangerous?

I think the clever solution you're looking for is covering the screw with a square of white electrical tape to prevent yourself from touching the screw.

You could also purchase nylon 6-32 machine screws with a flat head which are non-conductive.

That only fixes the sympom of the problem, but not the cause. Your excessive static electricity is from low relative humidity levels in the air. Increase it to 30-40% RH and you'll be happier.


Installed new breaker to relieve load in existing circuit. Still trips new breaker I recently moved a treadmill to workout room. Whenever the treadmill is in use, it trips the breaker shortly after starting up. I figured this is because the workout room also shares a circuit with another room that uses outlets for heated blankets and electronics. I decided to put the workout room on its own breaker with the exception of sharing an outlet which runs the heated blankets. I'm not sure when but sometime during the night the breaker tripped. To my knowledge only the heated blankets were running. The treadmill definitely was not running and this has never happened before moving the treadmill to the workout room.

The breaker I installed is a 15amp combination AFCI/GFCI breaker and neither the AFCI or GFCI tripped. It looks like this is due to overloading the circuit. How can I find the source of the problem?

NOTE: The treadmill has been runnning on a 15A circuit in a different room. The treadmill previously had an issue with shutting off after 5-10 minutes of use. The treadmill screen/panel would reset and just freeze up. I was told it was due to a fried/bad board from not lubing the belt. Haven't used the treadmill until it was moved to the new room.

You need to know what's all on these circuits and what they pull.  There's no substitute for this.

So it comes down to looking at the manual for every appliance on the circuit.  Considering of course that the appliance shouldn’t draw if it's off.

You can also use a Kill-a-Watt to directly measure; pay closer attention to VA than watts.

Once you've done your tally, you will surely discover an obvious problem, like 23A of loads on a 15A circuit. Rearrange as necessary.


Can dishwasher tubes do 360 loops? The dishwasher tubes that I bought are very long. The one going from the dishwasher to the air gap (white) drapes on the ground. The one going from the air gap to the garbage disposal (gray) makes a 360 degree loop. Does this matter? My knowledge of physics is not so good, but I vaguely remember that only the vertical height difference between the end points of the tubes mattered.

Update: I tested turning on the dishwasher. Water was spewing out of the air gap. This may indicate the loops are blocking water flow or something else is wrong with my setup.

As further discussed in your post here:
Is my dishwasher air gap manufactured incorrectly?

It's not that you cant have loops in the line, its more about having a proper run per manufacturers guidelines. The dishwasher has a pump, it is going to pump as much water as it can through the line to it's endpoint. Too long of a run will leave dirty water in the line, do not exceed the length or height the dishwasher tell you to.

For the disposal side of it, there is NO PUMP, so the air gap is that, all gravity.

From your other post, as water is going into the air gap, it runs to the disposal. However, in your run here, the grey line has a few feet of water sitting below the disposal, thus, you are going to need ~3'*5/8"ID worth of water weight to move water into the disposal. Shorten the grey line run, make it direct, and both problems in both questions should be resolved unless your disposal or trap has a clog or slow moving drain due to an impending clog or water flow etc.


Open Limit Switch on Trane Furnace: How to fix? My 8 year old Trane Model tuh2d120a9v5va furnace is not giving out heat. The service people are all busy due to the recent storms. Through the little glass viewing window I see red and green flashing lights. The red flashes 4 times, the green 3 times, and these overlap. The panel inside says the 4 flashing red means an open limit switch.

Where do I go from here?

Update: A 1" flat capacitor in the fan control module was fried black and cracked.  A new module and $1000 later and the heat works again.  Perhaps the power fluctuations due to the storm here caused some spikes that fried the module. I might put a surge protector on the line to the HVAC.

The high temp limit switches usually have a manual reset button that needs to be pressed to reset. I would try a reset it may have been a fluke that it tripped, if the reset dosent trip again it is probably fine. If it trips again you will want to verify the exhaust is clear, and the fan is freely spinning (some do need oil at each end to lube the bearings) low air flow on a high efficiency system can overheat the fire box.


How long do tree stumps take to decay? I had a large tree in my yard cut down to about 8' above ground. It now has two stumps joined at the base. I am planning to build a treehouse for my kids around the stump with the weight being held by 1/2 inch threaded rods through the trees holding up 2x10s.

The stumps are about 20 inches in diameter. I am worried that it might not be long before the stumps will rot and be too weak to hold up the weight of the treehouse.

How long of a life can I expect from my treehouse? Is there anything I can do to increase the life?

I am planning on treating the top of the stumps with bora-care to deter bugs. Any other suggestions would be much appreciated.

There are too many factors here to give any sort of objective answer:

Local climate
Tree species
Tree health
Location conditions
Future weather, insects, etc.

Ultimately it comes down to your tolerance for risk. A stump of that diameter will remain structurally sound at its core for a number of years, within reason. I'd consider it robust enough to support a modest structure (say 4x6 feet, weighing at most a few hundred lbs.) for at least four. However, the outer edges will begin to decay first. I wouldn't rely on lag screws, for example, for load bearing. I'd be cutting notches into the top of the stump to carry beams, and relying on mechanical fasteners only for stability.

Check it every year for signs of instability. It'll be fairly apparent when it starts to get sketchy.


How can I remove a stud from a load bearing wall? I want to remove a stud from a load bearing wall in order to recess my fridge another 3-4 inches.
In doing so I will be removing the bottom plate, one stud from bottom plate up to height of the fridge as well as drywall behind the fridge.

Is it sufficient to place  king studs next to the two studs that are on the left and right side of stud being removed and then run a header plate between the 2 that would support the remaining part of the center stud
. See picture.  Red studs are king studs in picture.

Instead of using king studs on either side of the header, use jack studs.

The jack studs take the load from the cripple and transfer it vertically to the floor.  You could attach to king studs as you showed, but the problem is you now have to worry about sheer strength as well.


Electronics drawing lots more amps that it should I recently powered up my 2 antminer S9 for mining bitcoin. Don't worry, this is all electricity questions.

So I have them running off a 240v single phase plug on a 30 amp breaker with wire gauge as follows: breaker to outlet 10awg;  outlet to junction box 12awg; and  junction box to individual plugs 12awg.

Now when I originally did the calculations for this I was going off the manufacture specs for power consumption which is 1330 watts each. meaning about 6.15 amps each. But after doing the install and everything,I stuck my clamp meter amp gauge on the wires. I'm getting 11.6A on one of the wires and 11.9A on the other. So if my math is correct this would mean that each one is drawing 2500 watts and that is WAYYYY outside of the amount of power this thins is rated to be able to produce. it is supposed to max out at 1600 watts.

The total length (from breaker to computer) is about 85ft total.  I know there is a voltage drop of like 3-4 volts but that's fine... it's just confusing the hell out of me why I'm getting such high amperage readings. I have one more machine in the mail still, and had originally planned to run it on the same circuit, but now I'm concerned that I have to now make a new run for the entire thing to have all 3 on one breaker.

Also this just hit me: a 30 amp breaker means 24 amps is about the 80% max line.  I'm drawing 11+- amps from each leg... so is that 22 amps on the entire circuit, or can I safely draw 24 amps on each leg of the circuit? Does anyone have any ideas how this is possible? Below is the spec sheet for the power supply from the manufacturer.

First issue here  is safety. With 12 AWG wire on circuit, circuit breaker should not be larger than 20A. This is  code violation.

OK, where are you measuring the current? On the common wire going into panel? If you have x amps current leaving panel on one conductor on 240 VAC circuit, then must have same current going back to panel on other conductor. So 11.9A total current x 240V =  2856W. Divide that by 2 = 1428W. Sounds about right to me.


Is it possible to rekey an Andersen exterior door with Kwikset SmartKey? I want to use the Kevo lock on my front door and have my back doors have the same physical key (even though they clearly will not have electronic keying).

To do this, I need to replace the cylinder on my Andersen doors with something that is compatible with Kwikset SmartKey -- either a SmartKey cylinder if possible, for "higher" security, or a standard Kwikset cylinder that the SmartKey locks can learn.

I can't find any information on what cores, etc, are compatible with Andersen doors or where to source them.

To answer the question: It is almost certainly possible to get a replacement cylinder for your Andersen door which accepts the Kwikset keyway, and have it keyed to accept the same key you're now using on the front door... or reset the front door to respond to the key the new cylinder ships with. My storm door uses a Euro-style cylinder, which is uncommon in the US but a good locksmith ought to be able to handle this request.

As others have said, though, I'd replace the SmartKey cylinder while you're at it. They were a nice idea, but they really have proven to be less secure than I'm comfortable with. A replacement cylinder should be cheap, and rekeying it doesn't add that much cost.


Is this wall load bearing wish to tear the wall between kitchen and dinning (orange arrow). Not sure if it is load bearing.

That wall is supporting ceiling joists so you can't simply remove it.

It's not carrying any roof or floor load as far as I can tell, so luckily no significant loads. If you want to clear span 13', use a 2 ply 1-3/4" x 9-1/2" 2.0E LVL. 1.55E LSL would be fine too, but that can be hard to find sometimes.

Typically remodelers try to put these types of beams up in the ceiling so they don't have to have a dropped beam with a soffit. They put the beam on top of the ceiling joists and use metal straps or strap hangers to carry each ceiling joist from above. The 2x6 ceiling joists will typically overlap a bit at the wall, so a 3" wide hanger every 16" can usually support both ceiling joists at the same time. It's a goofy way to do it, but each hanger would be carrying 200 lbs max so it could technically be done with just SDS screws but it's too much work to explain that to an inspector. They use hangers just to pass inspection easier.


central a/c won't cool My A/C unit was just checked last week- the tech said it had enough freon.  Monday we had a nasty storm- electricity flickered, but never went out.  After the storm, we noticed the a/c went on, but it doesn't cool.  Checked the thermostats and the circut breaker- both are working correctly.  What can be wrong?  The unit is 22yrs old.  The tech did say we are running on borrowed time.  He did mention replacing the capacitor and contactor.

It could be a variety of things, but there's no way to be sure without troubleshooting the system.
Thermostat
It could be that the thermostat isn't signalling the A/C unit to start.
Things to check

The indoor blower comes on
The outdoor unit turns on
There's voltage on the A/C signal wire from the thermostat

Control board
The control board in the air handler/furnace could be bad.
Things to check

The indoor blower comes on
The outdoor unit turns on
There's voltage on the A/C signal wire to the A/C unit

Contactor
If the contactor is bad, the A/C unit will get the signal to come on, but the unit will not turn on.
Things to check

The outdoor unit turns on
There's voltage at the normally open contacts of the contactor (T1, T2, T3)

Blower
If the blower in the air handler/furnace is bad, cool air will not be blown throughout the home.
Things to check

The blower in the air handler/furnace comes on
Air flows from the supply ducts

Condenser fan
If the condenser fan isn't working, the system will have difficulty removing heat from the refrigerant.
Things to check

The fan on the outdoor unit (condenser fan) comes on

Compressor
If the compressor in the condensing unit is bad, the system will not move refrigerant through the system.
Things to check

The refrigerant lines are different temperatures
The compressor turns on (may have to touch the unit to tell)

Restricted air
If air isn't moving through the system properly, it won't work well.
Things to check

Air is being moved by condenser fan
Condensing unit coils look clean and free of debris
Air handler/furnace filter(s) are clean
Air is flowing from the supply ducts
Evaporator coils are clean and free of dust and ice

Refrigerant level
If there's not the correct amount of refrigerant in the system, it will not function properly.
Things to check

Refrigerant lines are at the proper operating temperature (requires knowing the operating temperature)
Operating pressure of the refrigerant lines (requires a set of gauges)


How to give ventilation/exhaust to an inner toilet without exterior walls? In our proposed home, there is a common toilet (powder room without bath) but it has no exterior wall. However, it shares a wall with another toilet. Can you please suggest a way to give ventilation/exhaust to the first toilet?

Having a vent on a powder is nice but not required.  Since that room will not be producing high humidity the air technically doesn't require venting.  If the home is already built, that is why it most likely doesn't already have one (track housing is almost always built just to code; if the code doesn't require it, it will not have it).

If the house is not built yet, just ask for a vent to be added to the plans.  It can be vented to roof (if there is a roof directly overhead).  It can also be vented to the side of the house, vent line will have to run in the cavity between floors.

If the house is already built, your options are limited.  If there is attic over head, you can run a new vent easily.  Otherwise you will have to wait to your next remodel to run a vent.


Has anyone seen a plug like this before? It is supposed to be for a portable cooler. Wondering what it plugs into? Has anyone seen a plug like this one before? I am wondering what it plugs into. It is on the power cord for a portable cooler, and may be for a car, RV or boat. I am wondering if it is for another country other than the U.S.

That would be a NEMA 6-15 appliance plug. It's different so you don't plug an appliance expecting 220v into an outlet delivering 120v, which would multiply the current to dangerous levels.

Apparently they're also used in 12v (RV) applications sometimes.

See https://diy.stackexchange.com/a/89242/35141.


Why does my bathroom light go off and on after switch gets turned on I am curious to know if there is an electrical short in our home. I experience turning on light switches and then light goes off at times. It sounds
Like my tv sparks at times.

Based on saying you can push up on the switch and the light turns back on, the switch sounds like it's faulty and needs to be replaced.

This is a pretty easy DIY job. You need a new switch ($1-2 at any hardware store) and some basic tools, post back if you need help with the specifics.

If you've never done any electrical work before, please read up first and use ample caution. Electricity can be extremely dangerous, and it's why even people like me that have been doing it for years still carry around and use a non-contact voltage detector ($10-15) every time we go to touch any wiring, just to be really, really sure it's not live.


PEX pipe burst: what else needs to be fixed to prevent it happening again? I'm a renter in NYC and our 4-story building has recently-installed (within the last 8 years) baseboard hydronic heat. All of the tubing is PEX, except for from the boiler itself (as required by code) and a distribution panel with shutoffs for each floor, which is all soldered copper.

Earlier this week, our building had a piece of the PEX that runs to one of the floors split and explode, draining the system's contents into the boiler room. A plumber came, spliced in replacement pipe for the split section, and purged all the air from each floor's heating loop.

Here's the split piece of PEX:

The plumber seemed satisfied with the explanation that air in the system caused an overpressure and split this section. (I don't think the landlord has ever purged the air. The landlord did mention this has happened before at the building. He's not a quick learner.)

Anyway, working in software has left me unhealthily obsessed with root-cause analysis. I noticed another discolored bulge near the split, which looks a lot like burnt/overheated plastic to me:

It looks like there's similar brownish damage near the split itself. It's impossible to tell if the discoloration preceded the failure or not.

There are similar brown, bulging discolorations on other sections of PEX, and each discoloration is adjacent to a section of copper pipe in the same system.

Is this discoloration likely from when the copper fittings were installed and sweated, or from being directly above these fittings and slowly being exposed to heat coming off them?
Are these discolored spots likely to fail under normal circulating pressure if the system is purged of air regularly going forward?
Should these sections of PEX be replaced? Do they need to be insulated or protected from the copper pipe to meet either code, manufacturer's instructions, or just common sense?

(This is purely a learning exercise: it ain't my building, and I'm just curious in case I ever buy my own house with a boiler and PEX.)

PEX pipe does not corrode or otherwise interact with copper or other materials the way dissimilar metals do.  It's essentially an inert substance under normal circumstances.

The bulges and darkened areas, however, do appear to be signs of a problem and I agree with your assessment that these were caused by heat, probably from the torch used to sweat the nearby copper pipe joints.  The person installing the copper should have taken precautions to prevent heat from getting to the PEX pipes but clearly did not do so.

The damage has been done and the bulges show that failure is likely since it's the water pressure and NOT air in the system that is causing the weakened area to expand.  Once that process starts, it will keep "blowing up like a balloon" until it fails.

The damaged areas should be cut out and new sections should be put in.  Based on the obviously careless installation of the copper, an end-to-end inspection is called for.


Ideas/Advice for my Roof Rebuild I need some advice about drawing up blueprints for a new roof on our house. Thanks to some shoddy workmanship on an addition before we bought the house we need to completely remove the existing roof (framing and all) and put a new solid roof over the whole house. I am trying to decide what kind of framing structure to use on the new roof. We are also doing a complete floor plan remodel on the interior of the house. I have attached the blueprint of the final product.

The dimensions of the house are what is making this somewhat difficult. The house if 42x50, so that would make for a larger than usual truss. We are also wanting to have an attic space that we can finish someday to add a couple of rooms and have vaulted ceilings in part of the house.

From the research that I have done, it seems like the simplest and best solution is to use a structural ridge beam to help support the new roof. This would allow us to leave the entire attic space open and would also simplify the construction process because we should be able to leave the ceilings up in the house until we are ready to redo them as well. It also adds strength to the house because half of the weight of the roof would be supported by the ridge beam instead of all of the weight resting on the exterior walls.

I have attached an outline of where the ridge beam would go as well as where the vaulted ceilings would be. Can anyone offer any advise or a better alternative to a ridge beam?

House Blueprint:

(source: bateswebdesign.com)

Ridge Beam Blueprint:

(source: bateswebdesign.com)

Current Roof:

(source: bateswebdesign.com)

Call an architect. Seriously call one. Let them know what you'd like to do. Ask for some ideas. They can take the structure, age, other home styles in the area and give you a slew of options that are suitable and sound.

And it shouldn't cost that must either. They can suggest and sketch out rather quickly the style based on many factors including load weight, pitch, roof material you're going to use and more. There's modern materials, ways to get light in, sun roofs, venting, insulation that all factor in to a design.

A local architect is also in the know on building codes etc.

Looking around for ideas it's one thing but if you're serious about replacing the roof, an architect is the one to consult.


3 wire service to older building doesnt look correct Basically there's 3 wires running from a 125 amp breaker on the main service. A red(125v) A black(125v) and a white wire(neutral on ground/neutral bar) in main, all running to an older building with a 125 amp subpanel.

At the subpanel the bar that connects the neutral and ground has been removed. All the grounds are on one bar, all the neutrals are on another. The 2 hots are hooked correctly with awg #2. The neutral bar is connected to the neutral wire also #2 running back to the main.

The ground bar is connected to a AWG #2 wire to a grounding rod. So in this particular case wouldn't the bar that runs from neutral to ground in the subpanel need to be connected or something else?

The 3 wires are all #2 and are buried in pvc. not an electrician. but I do understand the basics. Don't need code talk, just regular speak please. Thanks in advance for your help. p.s. There's no water, gas or anything else metal underground near the shop.

First part is answered here: sub panel bonding. But in short, sub panels are not allowed to have their neutral bonded to ground. That only happens in the main panel.

Now to answer your grounding question: Yes, your sub panel is not properly grounded. Any fault current would have to travel through the earth back to the main ground rod or whatever grounded metal object is in the path first. The resistance of the earth varies and corrosion can also add resistance. This can create a high resistance enabling a ground fault (short to ground) to energize the garages ground circuit with a potentially fatal current without tripping a circuit breaker. In plain English: a short to ground could make every grounded metal object in that building live with respect to the main ground rod. A separate ground conductor must be ran from the main panel ground bar to the sub panel ground bar. That ground wire must also be in the same conduit as the other three feeder conductors and appropriately sized to the hot conductors.


How do I put up shelving that won't sag? What is the best way to put up a single shelf at top of wall to go all the way around the room for books

If you're sagging in the longitudinal direction, support lengthwise. If you can brace or support the entire length of the shelf, you can avoid a lot of the sagging. Sometimes even so much as adding a font lip will go a long way to making the shelves sturdier. Even a 1/2" x 1" strip, fastened with glue and countersunk wood screws will go a long way.

If even more weight needs to be supported, I've painted aluminum angle to the bottom of 40"x 26" MDF Shelves so they support Audio equipment in a cheap entertainment center, supported only by 4 steel pins.

Just remember, whatever you add shouldn't be so heavy as to take away from the load the shelf is intended to carry.

I.E. 2" steel angle on 1" thick boards as shelves may be overkill (ask me how I know)


Grout spacing for large format wall tiles I have selected large format Porcelanosa wall tiles (33.3 cm x 100 cm) for a bathroom. From the brochures I have seen, these tiles tend to be mounted with a very minimal, almost invisible grout spacing. Our builder has started to mound these using a more regular 3mm spacing, which I am worried will look odd. He said that trying to mount with a 1mm or 2mm spacing will result in the spacers compressing and making an even finish very difficult. Is this true, or is there some special technique needed for large format tiles with a small grout gap?

I think that 33.3 cm x 100 cm (13.1 inch x 39.4 inch) large format tiles will actually look good with a 3 mm (1/8 inch) grout line.

The builder is probably using clips to hold the tiles to the wall, and the ones I've used are thicker than 1 mm. These clips help make the tiles flush with each other as the tile adhesive/thinset dries. If they install them without using clips (or another system) it will be exponentially more difficult to install well.

If you want the grout spacing smaller than 3mm, I would ask the builder what the smallest spacing they can do without extra work with their clip system, and ask them if it's possible to use another clip system that would work better?


How can I hang a closet rod where there are no studs? I'm planning on using 1.25" copper piping to create 3 closet rods that extend from one wall of my closet to the other. On one wall, the stud is in the right place. On the other wall however, the stud is only in the corner and then the window framing gets in the way. And in case it matters, the wall in question slopes inwards 8 degrees.

What's the best way to attach the copper pipe to this wall? Should I just run three 2x4s off the corner stud? The problem with this approach is that the 2x4s would only be attached to that corner stud -- they won't cross another stud that I can secure them to as well.

Here's a picture so that you can see what that corner looks like with the window. In case it matters, the window is framed by 1x4s, and the framing protrudes from the wall (by around 0.75", or the width of the 1x4).

It is possible to fabricate some sort of support no matter what, it's more about what is the most expedient method of support that is not completely ugly. As mentioned by maple_shaft, there would typically be an intermediate stud between the corner and the window. It is conceivable that 24" spacing is being used and the only structure is at the window and at the corner. The window would typically have a least 3" width of rough framing at the side, mostly behind the trim, but allowing for frame thickness and rough-in allowance, there should be a bit of framing behind the wall finish you can nail into right along the edge of the trim. Even if completely behind the trim, you could, for instance, use a 1x6 support and dado it into the trim so that it has positive attachment to the underlying framing.

So now you have two points of support, one either side of the clothes pole. A 1x6 will be adequate to span between these points and look compatible with the trim. I agree you should use a proper clothes pole instead of copper. I assume it is the hard type that is somewhat rigid. (The soft type is obviously unsuitable) Even if it appears sturdy initially, under constant load, it will slowly bend over time (creep deformation) until it pulls out of it's support and falls.


Heat Damage to Laminate Counter-top Near Gas Range While deep cleaning our new home, after closing, my wife and discovered what looks like some heat damage to the counter-top next to the gas range.  The house was fully renovated about 2 years ago, just prior to the last owner buying the place, and the range/oven combo was installed as part of the renovation.  I'm new to gas appliances, so I'm somewhat uncertain as to what to expect as to the particulars of certain behaviors of gas appliances.
My thought is that the heat damage may have occurred before the gap covers were installed.  Is that so, or does this look like something that was likely to happen after the covers were installed?

There appears to be insufficient gap and the range appears to be too low. The easiest thing would be to raise the range by 3/4 inch to 1 inch. This might reduce heating of those areas.
EDIT
Might benefit from a stainless steel gap cover like this https://www.amazon.com/Stainless-Steel-Counter-SILICONE-splatter/dp/B089B6G3XZ
Current gap covers appears to be guiding flame onto counter.


Tripping of generator GFCI 30amps breaker I am trying to hook up my generator directly to the load center or control panel. To switch my supply from utility grid supply to my generator supply I'm using a double pole 30amp, 240v breaker. With the same load to my house, our grid supply is able to turn them on without any breakers tripping.
But, when I switch the mains of our grid supply off and turn the breaker of my generator supply on and turn on my loads , that's when my generator GFCI breaker trips.
I've tried to separate the main Neutral to ground bonding in my control panel to avoid double bounding and the GFCI breaker in my generator still trips when i turn on my breakers for the load.

Who ever wired up the switch board had the neutrals and the Earth mixed in the Neutral link and like wise in the Earth Link.
What could be the reason for the GFCI breaker in my generator to keep tripping once load is switched on.???

Absolutely not.  You are not allowed to do that.

Your proposal calls for backfeeding your main panel through an ordinary breaker (is it bolted down as required?). You do not have any interlock equipment (aka a sliding piece of stamped steel).  The setup relies on the "I promise, cross my fingers and hope a lineman doesn't die" method of interlocking.

That is not allowed, even for a minute.

Unhooking your neutral-ground bond isn't smart either

It's fine for testing purposes, but you were of a mind to simply leave your service panel's neutral-ground bond removed!   You can't do that.  That means that ground faults have no way back to source, which will electrify your entire grounding system.  The most sensitive points will be any NEMA 10 electric dryer and range connections, which do a sanctioned bootleg, connecting the chassis of their machines to the neutral wire. Congratulations, your washer (grounded) and your dryer (neutraled) now have 120V between them!

Put it back, and in the future don't even dream of energizing a panel that does not have its neutral-ground bond firmly established and checked out.

Seeing neutrals and grounds spammed onto the same bus is normal in a main panel.  It's not my preference but it's not wrong in any way.  The only thing it does is make it harder to convert it to a subpanel, which is effectively what you'll soon be doing, putting it downstream of an ATS.

Neutral-ground bonds vs. neutral-ground faults

I once had a panel that (unbeknownst to me) never had a neutral-ground bond, and there was a hot-ground fault on a branch circuit.  This biased the entire electrical system to have ground at the same potential as L1 (120V from neutral).  I found this out when I had shut off a circuit for maintenance and flashed hot to ground just to confirm.  I got a tiny blue spark and the circuit lit back up.  Then I realized any neutral-ground fault anywhere else would have started a fire, since neutrals don't have breakers.  After that I made sure my N-G bonds were shipshape.

Because N-G bonding problems + ground faults make a very hazardous situation.

As in my case, you have a ground fault.  You may notice that the mains breaker does not have a "test" button and is not a GFCI. (In Europe, main breakers are.)  Mains power does not care if your house has ground faults.  Your generator does.

It could be in any circuit, and may be a neutral-ground fault.  This is less dangerous because neutral is near ground, but more dangerous because neutrals don't have breakers, nor do grounds.  An unlimited amount of current could flow out the ground wire and back the neutral wire, setting both on fire. This risk goes up exponentially if somebody removes the neutral-ground bond, because this fault then becomes the system N-G bond.

Did I mention, neutrals and grounds don't have breakers.

(This also means you can't disconnect the faulty circuit by shutting off its breaker).

Subpanel

I recommend another, easier, safer way, especially in light of this un-chased ground fault somewhere in your house.   Get a sub-panel.  I would have recommended a Siemens panel with a $30 generator interlock for it, but you really need a transfer switch that throws all three conductors - both hots and neutral.  Otherwise the N-G fault off the main panel will continue to haunt you.  Do you separate ground and neutral in this panel? You bet - it's a subpanel.

Now you move one circuit at a time from the main panel to the sub.  Before the first move and after each, you spin up the generator and confirm no ground fault trips.  If you are moving over circuit #5 and it trips, gotcha.  With any luck, the naughty circuit is one that doesn't even need to be on generator, so the issue won't even come up.

When you get your ATS, you can simply connect its output to the main-lug input of this panel.  Rather than buy an interim 3-throw transfer switch, maybe you can accelerate the purchase of the ATS you really want.


Adding a manual transfer switch to handle a portable generator for my house My panel is in my garage just outside the kitchen door. The ideal place for the new transfer switch. I want to put the plug for the generator outdoors where the generator will be running. Can the plug be located that far from the transfer switch itself if properly wired? That way I don't need to run a really long cable from the generator through the garage, up the stairs and into the switch itself. Is this possible and okay to do?

Yes, you can run just about any length needed between the generator power inlet mounted on the side of your home to the transfer switch.  Of course the wire / cable will need to be sized right for the generator and distance.   Always a good idea to upsize the wiring in case you decided to go with a larger generator later.
Like @Harper-ReinstateMonica said, don't get one of those 6,8,10 xfer switches with the built in power inlet. Get a proper sub-panel with a interlock between the "power from utility" and the "power from generator" breakers.  Then move the desired circuits to the new sub-panel.   This type of panel is called a MTS (Manual Transfer Switch).
There is an other potential option that others here might disagree, depending upon the configuration and brand of your current panel. There are parts you can install on the main panel that created a mechanical interlock between utility power and gen power. There are pros and cons to going that route. Pro is it's a very inexpensive way to provide gen power to the entire home that is code compliant. Down side is you might not be able to free up the breaker space needed and 2) loading issues.  You may have to turn off several heavier loads so as not to overload the generator.
Safest and best practice would be to install the MTS sub-panel and move the desired circuits to it.


What are the pros and cons of prefab granite vs. custom slab? I am remodeling my kitchen and would like to put in granite countertops.  It seems that there are two main ways to get granite.

Buy a large slab and have it custom cut to fit the kitchen design.
Buy prefabricated slabs that are already cut and polished in 9'x2' sections.

The prefabricated route seems significantly cheaper - almost half the cost of the slab route.  Still, I wonder what the drawbacks are.  My kitchen will have two 90 degree corners, and I'm wondering how these are accomplished with prefab granite.  How do they make the corner seams look clean?  Also, is it possible to get fancier ogee style edges with prefab?

Overall, what are the pros and cons of prefab granite vs slab granite?

The big difference as you mentioned is price.  The seams with the pre-cut pieces should not be an issue (assuming the installers are good at what they do), the more noticeable factor will be the difference in colors and patterns.

If the entire counter is cut from a large slab, the colors and patterns will be consistent throughout the entire counter.  If the counter is assembled with pre-cut pieces, you may notice differences in colors and patterns from one piece to another.  The choice here, however, would come down to preference.  Some people might prefer the look of one method over the other, so it's hard to say what you'll like better.

I would find out if they have a show room or can provide pictures (from previous jobs) of the different methods, then you can decide which you personally prefer (while keeping your budget in mind).


Another 3-way switch problem I have a setup as follows: power, switch 1, switch 2, light. Wires are power to top of switch one, travelers from switch 1 to 2, and top of switch 2 to lignt.

For the following, I will call switch 1 power sw1-p, and the travellers sw1-t1 and sw1-t2, and switch 2 similarly.

I'm testing the switch screw against ground.

Testing results are as follows:

Switch 1 up   Switch 2 up   ---> light on
sw1-p  120v   sw2-p   120v
sw1-t1  35v   sw2-t1   35v
sw1-t2 120v   sw2-t2  120v

Switch 1 up   Switch 2 down ---> light off
sw1-p  120v   sw2-p     0v
sw1-t1 120v   sw2-t1  120v
sw1-t2 120v   sw2-t2  120v

Switch 1 down Switch 2 down ---> light off
sw1-p  120v   sw2-p     0v
sw1-t1   0v   sw2-t1    0v
sw1-t2   0v   sw2-t2    0v

Switch 1 down Switch 2 up   ---> light off
sw1-p  120v   sw2-p     0v
sw1-t1   0v   sw2-t1    0v
sw1-t2   0v   sw2-t2    0v

These results baffle me. What is the problem? How do I fix it?

I believe you have misidentified the terminals of the switches and miswired appropriately. I believe what you have identified as traveler 2 is actually the common “p” terminal. When switch one is down, your t1and t2 are connected and p is floating. Your second case is switch 2 feeding voltage back to switch 1.

By the way, the 35 volts is phantom voltage being picked up by your high impedance voltmeter.


Why does my house carry sound so much? My home is a 1100sqft, single story home and it carries sound very far and clearly.  It make the house 'loud'.  When I sneeze loud I hear a high pitch echo.  Voices seem to be amplified and with a slight echo.  Are there tools to verify what I am experiencing and what can be done?

The floor is tile.  The ceiling does not have 'popcorn'.
The house's layout is like this:

_ = walls
. = hallway
M = master bedroom
B = bathroom
R = bedroom
K = kitchen + dinning room
L = living room
G = garage

[    ][B1][        ]
[ M  ][B2][_   K   ]
[___]......._______]
[R1 ].[R2 ].[      ]
[___].[___].[   L  ]
[         ] [______]
[    G    ]
[_________]

Make sure you have carpeting, or even area rugs.  Get some furniture in the place.  Then move up the walls with various artwork, preferably some kind of cloth or canvas.  You'd be amazed at how much a hanging tapestry absorbs sound.  The emptier the home, the more you'll hear echoes.

Edit: I almost forgot, hang some curtains.


Help with c wire on American standard air handler there is no"C" indicated. Model TWE040E13FB
 I have taken pictures of the connections and looked at the wiring diagram however I cannot figure out which wire is any help would be appreciated thank you

Looking at the schematic...

The red wire is R, while the blue wire is C.


Does door jamb size make a difference in installation? How can I install a 34 inch door made for a 4 inch door jamb in to a 6 inch door jamb. Can it be done?

Yes. Set the door flush to the exterior. Google "jamb extension" for the rest. (Your jamb extensions will probably be 2", so likely to require ripping.)


Which thermal circuit breaker should I buy? I live in a small house in Argentina where we use 220 volts. I have a thermal circuit breaker that do squeak noises when the iron starts or the fridge starts. I adjusted the four screws of the breaker but I saw it was broken. When I adjust one of the screw, it separate the plastic thermal circuit breaker. I would like to know why I have to adjust the screws periodically.
 I want to replace the circuit breaker because this breakage: what features should has the new one?

replace like with like.

look at the print on it and see what amperage it is rated for and get one with the same rating. the one picture is a double pole breaker that will shut down both leads when either one is overloaded.


Why is my water expansion tank leaking? I live in the northeastern US and we just turned the heat on (oil) and this morning I went down to the basement and saw this:

The water is coming from the plumping above something labeled "water expansion tank". In the picture below, you see the green patina forming over the copper pipes above the tank.

My questions:

What is a "water expansion tank"?
What does this tank have to do with my heating system? Is it just coincidence that it started leaking right after turning on the heat, or does the boiler engage the tank somehow?
What is the likely root culprit here, and how might I diagnose what is exactly wrong with it (and then, subsequently, fix it myself)?

A water expansion tank gives water a place to expand in a closed system (frequently found with boilers, or home water supplies with a check valve). Otherwise, heated water cannot expand and instead increases pressure until some component of the system leaks or explodes.
If the tank is on the hot water heating system, then it's there to relieve expansion from the water being heated. I can't tell from the photo if it's on the heating system or on the home water supply.
Leaks tend to travel down with gravity, if you see evidence of a leak above the tank, then it's likely at the top of that evidence, not the bottom. Shutoff the water, find the source of the leak, and replace the problem area. It may be as simple as needing to unscrew a threaded connection, clean the threads and apply pipe dope, then tighten everything back up. But with visible damage, you'll likely need to to replace the problem area with new pipes.


Moderate localized water damage that's hard to inspect from above I have water damage in the ceiling along one end of the house. It wasn't detected for some time because it was in a room we don't often go into.

There was an unpleasant musty smell, but it has abated. Still, I was worried about mold on the other side. Unfortunately, it is difficult to inspect the location:

The area of the leak is around the middle of the flashlight spot. We think the leak was from blown rain around the place where an AC line entered the house. That has been caulked. Assuming the damage doesn't get worse, is it safe just to repair it from below without examining it from above?

I don’t see ANY discoloration (black stains, etc.) on the studs or roof joists. Therefore, it’s minor and hasn’t damaged the wood structurally or caused mold.

The damage is what I’d classify as insignificant. It’s not worth tearing up your attic to see the damage from “above”.

If you’re not sure you’ve stopped the leak, you could take an ink pen (a pencil won’t work) and draw an outline around the perimeter of the leak/stain. Keep an eye on it for one rainy season, then fix the ceiling. If it leaks again, keep a journal and make note if it leaks during heavy rain, strong winds, rain coming from the west, etc. It’ll help you find the “real” leak later.


Firewall on existing building We are required to create a firewall on our building that is less than 5' from the property line. We removed a window and now need to know if we can just leave the old header and framing and insert studs at 16" centers within the old window opening. Can anyone offer insight into this?

thank you.

Absolutely, that is common practice. Not much insight required, sounds like you got this.


how many ring or radial socket makes a circuit like how many sockets can one have on a either ring or radial circuit planned to be protected by 20A breaker

The number of sockets you can have connected to a circuit isn't limited by the circuit breaker's amperage. No matter how many sockets you connect, you're still limited by the 20A limit on the circuit breaker. A socket with nothing connected to it does not draw any current.

Think about what devices you want to connect to the circuit. Find out how many amps each one draws and total that up. A 20A circuit can supply 20A intermittently or about 16A continuously (load for more than 3 hours at a time). Use the total amperage you need to supply to determine the number of circuits you need.

If you wish to connect multiple devices, but not use them simultaneously, you may do so as long as they don't exceed 20A or they'll trip the breaker.


What is the difference between a coaxial grounding block, an antenna discharge unit, and lightning arrestor I've been reading about grounding outdoor TV antennas but these terms seem to be used interchangeably by various articles on the internet.

For example, this article seems to make a distinction between (coaxial?) lightning arrestors and coaxial grounding blocks. It says:

"Mount the grounding block as close as possible to where the 75 ohm coaxial cable downlead enters the house"
"The antenna discharge unit (also called a “lightning arrestor”) is connected to the transmission line at a point close to where the transmission line enters the house"

So we should install both the grounding block and lightning arrestor near the place where the coax enters the house....

Ok, but what about this article: "To protect yourself from a direct strike, attach a lightening arrester (sic) to the antenna mast" (huh? I thought it goes near where the coax enters the house).

Lastly, this one says: "The coax cable itself can build up a static electric charge and in order to properly dissipate that charge an antenna discharge unit or grounding block can be used" (so now it seems an antenna discharge unit in fact isn't a lightening suppressor...)

This is all somewhat confusing to an antenna newbie like myself. Does anyone have a cogent explanation of these three items (and perhaps some indication of the ideal places they are installed)?

Antennas can build up a sizeable static charge which needs to be dissipated. Unfortunately the obvious solution of grounding the antenna also removes the signal from the wire. A coaxial grounding block allows static charges to dissipate from the center conductor without interrupting the signal.

More elaborate devices are filled with a gas which is ionized by high voltage spikes to create a very low resistance connection to the ground. This allows lightning traveling through the cable to be arrested. Both grounding blocks and arrestors are discharge units, which dissipate the static charge from the antenna. Only the arrestor provides protection against lightning.

Ideally either would be installed as close to the point of entry as possible. The cable run itself has all the drawbacks of metal suspended in air. It can gather a static charge, and conduct lightning. Also, as the first article points out, you may need a second ground wire if the antenna is atop a metal mast. Though the mast can be connected directly to the ground, since signal loss isn't an issue.


Do I need to add support to hold second floor joists while working? I need to replace the header above a 1sr floor window. It is 2 2x10# at 48 inches across with a piece of osb sandwiched on top of a 2*4. I am curious if I need to build a support "jig" while I am working on the problem area. Windows and siding were recently replaced everything is bone dry now so just was trying to figure out how far the cancer spread and got a little deeper than expected. Thanks in advance for any help or advice.

Do you need too?
Probably, but that may depend on exactly how much is above the header/load bearing wall you're taking out.
Should you?
Yes. Build a temporary wall to support the joists, ceiling, upper floors, whatever is above this. The cost in time and supplies is minuscule in comparison to any damage that may happen to the structure while you've got that load unsupported. Additionally, your insurance company could use the lack of temporary bracing as an excuse to not pay a claim, making it even more expensive.
While you're at it, ensure that your load is carried all the way down to the ground. You don't indicate if you've got a slab, basement, or crawl space, but if you're not on a slab, you'll want to build a temporary wall in the basement/crawl space directly below the one you're building above. This will support the joists right where the load is instead of bowing them down with the weight from above. Again, consider the actual costs vs the potential costs to repair damage.


How to open this air return duct between joists I got dead rodent in return duct, at least I hope I will find it there. My returns on bottom and supply on top. Strong smell from return in one bedroom. Attached is pictures how this duct look from a basement. One end is next to window (where it goes up to the room). Another picture is where sheet of metal meets another one. It's about 8ft long.

I need to take that section out, I believe this is where rodent will be.

How do I take this piece out? Never took ducts apart, need some guidance, don't want to break anything..

The thing that runs perpendicular to the duct sheeting looks like a standard z folded clip. Not sure of the mechanism of the sides, but they are probably simple slots.

After laying plastic sheeting on the floor and donning a dust mask and gloves, I'd try simply shoving the bottom of the duct upwards. It should buckle and come apart, dumping everything onto the floor below.

Re-assembly is probably easier if you use sheet metal screws and foil tape.


Can I use pex for this connection between the shower and the tub faucet? Can I use pex from my shower valve to my tub drop ear elbow?

Yes, you can. But there's an important caveat here. The other connectors are using Sharkbites, which are push connectors. The two in your picture are a compression fitting. You'll either want a crimp ring or a clamp ring to secure the pex to the fitting. These might require a special tool. You might also get away with using a regular screw clamp.


Why does my drill stop and start working when it feels like it? I have a makita drill that still works but sometimes stops working then starts working again. Any ideas what it could be?

If it's a corded drill, that's a common sign that the cord is going bad and it's time to replace it. It might also be the power switch (see below).

If it's a battery drill then look to the power switch. Dirty contacts will cause intermittent power loss. You may just have to spray some contact cleaner into the switch assembly and work it a few dozen times, repeating the spray too, to get things working reliably. Battery contacts might also have gotten dirty. Clean them.


Sand-blaster or angle-grinder to remove rust? To remove the rust from my beloved barbecue pit, I am considering using an angle-grinder or renting a sand-blaster. Having never used either tool, there are several spots that look hard to reach with a grinder which is why I’m considering renting the sand-blaster.
Which tool would be a better match for the task?

No contest

Sandblaster doesn't just beat, it positively trounces any other rust removal method.

That's not me talking.  It's NASA.  Their location at Cape Canaveral ("Who picked this place? Nikita Khrushchev?") ... has a huge problem with rust due to being tidal and subject to sea spray.  What a lovely place for millions of tons of steel latticework gantry structure, in their dozens of launchpads.  So they have a rather significant division dedicated to rust control, and they have a web site: http://corrosion.ksc.nasa.gov which you can read yourself.

NASA, naturally, "did the research".  They have, for years, prepared samples using various techniques (not to mention their experience maintaining their own structures).  Media blast to SSPC-SP10 (near white metal) is head and shoulders above the second and third, which roughly tie: needle scaling and grinding.

Once you've media blasted to near white metal, the quality of your paint is the deciding factor.  We had somebody media blast a metal structure, then paint some of the first "non-lead" primer that I procured for $11 a gallon ($25/gal inflation adjusted) at a local paint manufacturer, then topped with their same brand black alkyd topcoat. 20 years gone, the black started chipping and peeling, but the primer is still going strong. Less than 0.5% of the area has any detectable rust activity.  On the other hand I've used excellent $90/gal primers on power-wirebrush prep, and had it fail within 7-8 years.


Should I descale my Saniflo macerator after neglecting to do so for many years? I've been in my home for 16 years and have a Saniflo toilet / shower combo in my basement. I have never descaled it and have never had any issues. Am I rolling the dice by not doing it or would it be too risky to do it after such a long period of time.

We do not use the toilet often, and the shower even less, if that matters.

Yes use their descaler they recommend it for a reason. Life expectancy is 10 to 20 years. It is out of warranty by 14 years and close to end of service life. Take care of your poo squisher.


Can I drill or notch a 2x2 bottom plate in a flat-stud wall? Trying to get low-voltage cables from the basement to the attic, the best route goes through a utility closet framed with a flat-stud wall on two sides (the third side is an exterior wall which I would prefer to avoid). The bottom plate is a 2x2 sitting on top of the floor.

I can't find any mention in the building code here in Seattle about limitations on drilling or notching of bottom plates, only of studs and top plates. Should I take that silence as an indication that it's okay to drill or notch as much as I want of the 2x2 bottom plate in order to bring the cables through? Would removing a entire piece of the bottom plate be an option?

Bottom plates typically don't carry any load. You can feel free to drill as needed there. Really, you could remove an entire section of the plate and probably not encounter code violations. Drywall will span gaps of 4-6" without a problem, assuming it's protected from impacts.


Leaking portable air conditioner We have a portable air conditioner that we used pretty heavily over the weekend. When I woke up this morning, it has leaked water all over the living room floor. Any ideas of why? Thanks!

...because you didn't empty its drain bucket/tank? Lacking the usual "outside part" where window air conditioners drip condensate, portables usually have a bucket or tank like a dehumidifier that you need to empty. It might have a float that is supposed to stop operation when it's full - like dehumidifiers, that float mechanism may not be completely reliable (if there is one.)


Why does this toilet clog so often? My inlaws have one toilet in their house that regularly clogs. They have two more toilets that don't seem to clog at all. They live in a suburb with full plumbing (not a septic tank). The toilet isn't low-flow. They had a plumber come look at it, plumber says there's nothing wrong.

But every third time we visit, my husband clogs it. Or I do. Other guests seem to clog it, too. The residents don't clog it. My husband and I don't usually clog toilets. We do eat more meat, less fiber while visiting, but we travel tons and put up with drastic dietary changes and new plumbing all the time, and we don't clog toilets. Just this one.

What makes this one exceptional is that we often have to snake it when it does clog. Just plunging never releases the clog.

Is the plumber nuts? Is there something else going on here?

Troubleshooting steps/questions:

Has this toilet always had this problem, or was there ever anything installed in this location that didn't clog like this? If the toilet has always had this problem then it's likely some issue with the initial installation; the drain pipe diameter may be too small, or there may be insufficient venting which is causing slow drainage in the wall because there's no "air behind water".
If it didn't always have this problem, then something has changed. Would that be anything obvious like a remodel, or something more gradual like build-up accumulation? If the toilet was replaced at some point, either as its own job or as part of a larger remodel, then most likely something was done during construction/installation that is causing an obstruction. If not, then mineral or organic build-up is the most likely culprit.
From the comments, what DID the plumber do, if he didn't scope the drain, lift the throne, and/or inspect the vent stack from the roof? Anything he did do, besides flush a toilet with nothing but clean water in it, may help to eliminate or diagnose potential problems.
Does the toilet always seem to drain slowly, even if it doesn't clog outright? Slow drainage of the bowl in all circumstances would point to an obstruction of the pipe diameter itself, such as an improper flange installation, a defect in the toilet, or blockage in the piping. Fast flow in a "normal" flush, but easy clogging, generally points to a foreign object blocking the pipe in such a way as to trap solids as they go down the drain, but allowing water without any solids to pass by normally.
Are there small children in the house? A child could have flushed a pencil, pen or other long, stiff object which is now caught in a turn in the plumbing and is trapping solid matter to form clogs. Scoping the drain will identify this blockage, and a professional snake will clear it (the homeowners'-variety snake with a coiled end won't do anything; you'll need a snake with bladed ends designed to chew into or through solid blockages, which require some knowhow to use without further damaging your drains).


When did the NEC code start to require the separation of neutral and ground bus bars after main disconnect? You gave the answer below to the question of the requirement for separate bus bars after the main disconnect box ... my question is ...

In what year did the NEC start to require this separation?
What is the code number?

There are supposed to be two bus bars in every panel. One for neutrals, and one for grounds.

In the main panel ONLY, they are to be bonded together. This is what references your electrical system to earth voltage. It must only be done one place in a system.

Because of the required bond in the main panel, a great many electricians conclude that there is no difference between neutral and ground in the main panel since the N-G bond is right there. And they simply spam all neutrals and grounds onto the same bus. That logic is actually... reasonable... in the main panel.

However... If you want to be a precise and competent worker, then you separate them always, as if every panel were a subpanel, and let the neutral-ground bond do its job.

You're after NEC 250.32(B)(1)

The applicable NEC section is 250.32(B)(1), which reads as follows ("equipment grounding conductor" = "ground" and "grounded conductor" = "neutral" for us, and exception 2 is irrelevant for this):

  (1) Supplied by a Feeder or Branch Circuit. An equipment
  grounding conductor, as described in 250.118, shall be run
  with the supply conductors and be connected to the building
  or structure disconnecting means and to the grounding electrode(s). The equipment grounding conductor shall be used
  for grounding or bonding of equipment, structures, or frames
  required to be grounded or bonded. The equipment grounding conductor shall be sized in accordance with 250.122. Any
  installed grounded conductor shall not be connected to the
  equipment grounding conductor or to the grounding electrode(s).

  Exception No. 1: For installations made in compliance with previous
  editions of this Code that permitted such connection, the grounded
  conductor run with the supply to the building or structure shall be
  permitted to serve as the ground-fault return path if all of the following
  requirements continue to be met:

  (1) An equipment grounding conductor is not run with the supply to
  the building or structure.

  (2) There are no continuous metallic paths bonded to the grounding
  system in each building or structure involved.

  (3) Ground-fault protection of equipment has not been installed on
  the supply side of the feeder(s).

  If the grounded conductor is used for grounding in accordance with
  the provision of this exception, the size of the grounded conductor shall
  not be smaller than the larger of either of the following:

  (1) That required by 220.61

  (2) That required by 250.122

The current state of this section was reached in the 2008 NEC, which forbade new construction from using the feeder neutral to provide ground for the fed system.  (Your choices now are to provide a separate ground wire, which is what is normally done, or use a distribution transformer to create a separately derived system for the fed building, which has its own N-G bond.)  Many of the installations that fall under the current exception were installed prior to the 1999 NEC, which is the first edition that forbade parallel current paths between the structures involved.


Restoring worn down steps Want to take up another DIY at home, restoring steps to attic. I want to clean them up and make them shine. I see tons of products in Lowes and home depot on Floor restore/shine.
Anything you guys recommend ?
Right now the steps have paint droplets and dust(tried to clean the dust with vaccum cleaner but doesnt go).
Thanks in Advance.

Keep it Easy
If you're not looking for a specific finish, and just want something shiny and better than what's there now, and given it's the attic stairs and not your Grand Entrance:  I recommend you start with an easy approach.

Sand the stairs down with an orbital sander.  Go for 80/20 approach, stop sanding when it looks pretty good. That will take about a day. Don't spend another week making it 99%.
Apply two coats of tinted water-based polyurethane.  That's another day but mostly just waiting.

Very little effort, very little money, and it'll look pretty nice.   Then you can spend a year perusing woodworking sites, watching youtube videos and historical renovation sites to see if there's something you like better.


Re-key or just replace deadbolts? Our house has Schlage "bright brass" deadbolts on the front and back doors, which use different keys. Our separate garage had a no-name unit. We never had keys for the rear door or garage. I just replaced the garage deadbolt so I would have keys. It only took a few minutes, and that got me thinking...

What is the easiest/simplest/cheapest way to get the front and back doors to share keys?

re-pin the rear door, which Home Depot will do but I didn't get a price
get new cylinders for both, but HD doesn't sell them
replace both deadbolts outright

HD has Schlage brass deadbolts for $58. Ouch. Weiser is $40, Defiant is $19 (although not quite the same color). Is there any real difference between these?

It massively depends on the quality of the locks. I buy Home Depot cheapies, and I just replace locksets using the package codes on the lock-sets to get multiples of the same key.  (If you have 3 sets that all say "Key Code 12589”, they will all have the same key).

However I am transitioning to using Schlage Primus, a dual-keyway patented system which precludes unauthorized duplication, and warrants top-shelf hardware.

Go find the kind of locksmith who has a bricks-and-mortar presence with a showroom (and isn't all outbound).  Bring in a lock you want re-keyed, with the key that works in it, and the key you want to work in it.  Come up to their counter.  They will tell you whether it's worth re-keying.

By that I mean there are 3 kinds of locksmiths:

Virtual locksmiths, who only exist on Google, and harvest the identities of people who need locksmiths, so they can "generate leads" (sell you as a sales lead to a locksmith), or engage in criminal behavior toward you, such as casing your home whilst getting a copy of your key.
Truck locksmiths, whose business is a van, and who mainly do emergency work.  They only do outbound work, always charge a hefty service call fee, and have gotcha pricing on everything else.
Showroom locksmiths, who do outbound but also have a retail premises you can visit with a halfway respectable showroom. They will do amazing stuff for you very cheaply.


Is it possible to self install a grounding rod? This has been a baffling question as I notice electrician charge an arm and a leg to upgrade electrical systems in a home.  My home was built in the 1930s and it’s not grounded.  I was wondering if a grounding rod is just a long stick that goes deep down in the ground.  If so, how deep should I drill?  Second, if I just connect that to the cold water pipe, I can ground all my outlets to that cold water pipe?

Yes, you can install a ground rod yourself.  They are typically 5/8"-1/2" thick 8' long copper rods, which need to be driven entirely into the ground.  It's common to use a large hammer drill, or small jackhammer, with a ground rod driving bit, to drive the rod.

However...  Driving and connecting a ground rod, is not all there is to grounding an electrical system.  If you really want to do this work yourself. Find a person with knowledge and experience with this, that is willing to teach you. If you can't find somebody, go get a couple books on the subject. Study the books cover to cover, and make sure you understand the information before you begin work.

And no, you do not connect things to the plumbing to ground them. Though you can sometimes use the service plumbing as a grounding electrode, and you will have to bond any metal plumbing within the building.

Grounding isn't about connecting to the earth (dirt), it's providing a safe, low resistance path back to the source (service). While ground rods (and other electrodes) are part of the grounding system, they are not the most important part of the system.


Plywood subfloor won't screw down in a trailer home I'm remodeling my mom's bathroom and I'm putting 1/4 inch plywood down on top of the floor to get a smooth surface. The existing floor is strong but there was some deflection in it and it's not as smooth as I would like for stick-down tile.

My question is when screwing the quarter-inch plywood down, I can't get the screws to the bite down to go all the way in.  Any answers to what kind of screws I could use to screw it down? I do not have a compressor for a nail gun or staple gun to do it that way and I don't think quarter-inch plywood would be okay with staples.

I just really need to know what screws will bite down and countersink.

When you say "bite down" do you mean:

It actually goes through the layer beneath the newly laid 1/4" plywood and simply spins as though it's stripped and will not counter sink, or
It will not even sink far enough for the head of the screw to even touch the new layer of plywood?

If it's option 1, are you using a wood screw or machine screw? A machine screw (self tapping or otherwise) would not be a good option for use in this scenario, or most scenarios when the underlying material you're fastening to is wood. The threads are too fine and tend to strip the holes easily. You should be using a wood screw, which has fewer threads per inch (TPI).

If it's option 2, I would agree with @JPhi1618. Consider using a shorter screw so you are not piercing the underside of the floor. This could potentially allow moister to wick in from the underside and rot out the exposed ends of the screws and eventually the subflooring. At minimum, the driving depth of a fastener should be no less than double the material you are fastening. In this case, you are fastening 1/4" plywood, and the math says 1/4" x 2 = 1/2". Therefore, your screw should be at least 1/2" long.

I am guessing that what you mean by a "stick down tile", you are referring to a peel and stick flooring? Similar to  found here Home Depot link to the example picture

Personally, I would be hesitant to use a concrete backer, simply because of the amount of dust that sits on top of the backer regardless of how many times you sweep or vacuum, but that's just personal choice. Regardless, I would definitely suggest priming the surface to help ensure a dust-free, clean surface so the tiles will have a better stick-to-it-ness (I just made that word up) and is less likely to have corners curl up prematurely or bubbles appear from what might seem "out of the blue". Best practice, for sure, is to follow the manufacturer's suggestions on underlayment and surface prep.

Hope this helps!


How to permenantly close and seal wood fireplace We don't use our fireplace and would like the wall space back.   Is there a right way to seal everything up?   My approach would be to cap the chimney top and plywood + drywall the front opening.

It's an external chimney, the firebox is brick, and I assume the flue is ceramic.  There is no damper.

Removing the facade is not usually very hard. Where you will run into quite a bit of work for a brick fireplace is with the hearth. Usually these are poured and removal may require a jackhammer, sometimes only a heavy demo hammer is needed. As your hearth is above the floor level it may be part of the base of the chimney.  So removal is not a minor job but could be done DIY.

I understand you want to reclaim the space but for me it would be all or nothing . Remove the entire thing for a few inches of space, or install a gas or pellet stove insert and seal it so you don’t loose heat up the stack. I have installed gas log inserts that ran for a month on a 5 gallon propane tank, this increases the home value verses the cost of demo and reducing the home value. I did remove a fireplace in my 1930 farm home as it was in a poor location and was not safe to use. However I added a free standing high efficiency stove in another room (addition). I would use caution with a partial demo as that could be considered a liability for future sales this is why I say all or nothing, a fireplace that is not usable will reduce the value or has in the past, a simple change to a gas log insert brought the value of one home we flipped ~15k and that was 20 years ago.


Why is it illegal to change temperature of water heater? The title is a little misleading. I know why it’s illegal, but I think what’s really important is the end result (users, especially children, don’t get burned). I’m curious why it isn’t equally as legal to turn the temperature up as high as supported by your water heater, but use a thermostatic mixing valve to regulate the temperature to 120°F. With this approach you would effectively increase your hot water capacity without having to install a larger tank.

You can do this, but not as completely as one'd want to

The approach you describe (running a tank full-hot and then downmixing it to a scald-safe temperature using an ASSE 1017 central thermostatic valve) is indeed permitted by the Codes, although it does not negate the need to provide scald-safe fixture valves at showers and baths.

However, one drawback of this approach is that it limits the protection from Legionella growth provided to the hot-water piping system.  In most applications we consider here, that's not a huge drawback; however, it does mean that care should be taken to avoid "dead legs" of hot water plumbing, as those are common hangouts for pesky Legionellae.

The ultimate system uses an anti-scald mixing valve feeding directly into an anti-scald fixture at baths and showers, and an anti-scald mixing valve at bathroom (and perhaps kitchen) sinks as well, allowing untempered water to be fed to clothes washers and dishwashers to minimize the need for booster heating.  This is more commonly done in the more complex commercial/institutional plumbing environment, but is theoretically doable for residential work as well, although the standards for mixing valves are in a bit of flux at the moment.


How can I prevent silt from clogging my yard drain? In my concrete back patio, I have a standard 4" square drain cover which allows water to enter a sewer pipe about 6" below.    The issue I have is that the sides of this hole are not covered in cement or other material, so sometimes you get mud coming in from under the concrete and clogging the drain.   When the lake appears in our back patio, I clear the congestion with my hand.

Who's got a good solution?   I was thinking maybe cut open the patio to put in a 12" square cover and then have some room to create a better concrete "sink" to keep mud out and direct water to the drain.   Other ideas?    Also, who would I call to do this work?

Update & Resolution:
Using @FreeMan advice, I ended up filling the gap with hydraulic cement.  So far, so good!   Having not worked with concrete before, I was impressed with its ability to stay put (and not fall down the drain before curing).  Third pic is proof of work.

I'm trying to figure out how there's so much dirt inside the frame that the grate screws into. Can you dig that back some? Is that just surface dirt that's been washed in there and collected over the years or is it coming up from below the slab?
If you can excavate some of that dirt around the outside of the drain pipe, I'd do that, then put a fitting on it and a small piece of pipe to extend the drain right up to the bottom of the grate. That should keep the mud from under the slab out of the drain while still allowing the slab itself to drain reasonably well.
I'd also suggest snaking out the drain as you've likely got quite a bit of gunk in there.
An update based on the explanation in the comments:
Since what I saw as dirt around the drain pipe is more of a concrete "funnel". It appears that this is the location where water & dirt are bubbling up from below.
I'd suggest using some silicon caulk or epoxy as a filler around the top of the grate frame. You want something that's designed for outdoor use and can take some wear and tear, as well as remaining flexible enough to not crack in freezing weather*.
This should prevent things under the slab from working their way to the top of the slab and then down the drain.
Another possibility would be to skim the entire surface of the slab, since it's looking pretty tough, with some self-leveling cement, then coating the entire surface with an epoxy finish that's specifically designed for concrete floors. There are a variety that are designed for garage floors - these should be durable enough to hold up to a non-garage, but outdoor use. When you're applying the epoxy, cover over the screw hole in the grate frame to ensure you don't fill it, then bring the epoxy down into the frame to cover that gap.
*I'm making the assumption that you live in an area where freezing occurs. I see a couple of cracks in the slab, and the other wear on the concrete looks like it's led a bit of a rough life.


What is the white, crusty, crumbly stuff I find in my kitcken sink drain pipes? From time to time my kitchen sink needs to be unplugged, and each time I invariably find accumulations of a crusty, crumbly white material in the pipes. It looks a lot like old cheese, has no particular odor of note, is often in ring shapes (so I assume it is accumulating against the pipe walls), and can be quite hard at times requiring a fair bit of manual force to snap out of place.

These accumulations don't occur at our bathroom sink and bathtub drain, both of which have corrugated plastic hosing, so I suspect it is biological (feeding off sink detritus) rather than mineralogical?

Just curious!

It sounds like calcium build up to me, are you sure it's not mineral? Is your water hard? When I have replaced the PVC pipes in my sink, I occasionally see exactly what you describe, but in my case it is because of our hard water.


15amp switch load clarification If you run a 20 amp circuit (12/2) with shared lights AND receptacles, can you use a 15amp switches? Its my understanding that the switch is rated for the load its carrying (lights), but what about the load of the whole circuit? Lets say you have a room on one 20 amp circuit supplying outlets(15amp rec) and lights(15amp switch)you plug in a vacuum cleaner, have mini fridge running, and a fan plus lights, you pull more than 15 amps on the circuit. The breaker won't flip, but will the light switches rated for 15amp be ok?

Using 15A light switches to switch <15A on a 20A branch circuit is OK, unless you're switching receptacles!
As it turns out, NEC 404.14(A) permits the use of a snap switch (general light switch) to control any hardwired, non-motor load up to its rating, or motor loads under specific conditions (informational notes omitted):

404.14 Rating and Use of Switches. Switches shall be used
within their ratings and as indicated in 404.14(A) through (F).

(A) Alternating-Current General-Use Snap Switch. A form of
general-use snap switch suitable only for use on ac circuits for
controlling the following:

(1) Resistive and inductive loads not exceeding the ampere
rating of the switch at the voltage applied

(2) Tungsten-filament lamp loads not exceeding the ampere
rating of the switch at 120 volts

(3) Motor loads not exceeding 80 percent of the ampere
rating of the switch at its rated voltage

Note, though, this doesn't hold true when you're switching receptacles, as someone could plug say, a space heater into the receptacle(s) and exceed the rating of the switch as a result (informational note omitted again):

(F) Cord- and Plug-Connected Loads. Where a snap switch or
control device is used to control cord- and plug-connected
equipment on a general-purpose branch circuit, each snap
switch or control device controlling receptacle outlets or cord
connectors that are supplied by permanently connected cord
pendants shall be rated at not less than the rating of the maximum permitted ampere rating or setting of the overcurrent
device protecting the receptacles or cord connectors, as provided in 210.21(B).

Exception: Where a snap switch or control device is used to control not
more than one receptacle on a branch circuit, the switch or control
device shall be permitted to be rated at not less than the rating of the
receptacle.

The reason why is in your hypothetical case, the wall switches are not in the path of the current the vacuum draws, basically.  (Keep in mind that current flows in loops and that loads connected are in parallel.)


Removing sand-blasting residue from window glass I had some surface paint removed from my patio floor and some of the sand ended up on the surface of the window near by. It almost looks like it stuck to the glass. Is there any nice way to remove these sand particles without damaging the glass surface?

You wouldn't be asking if it just wiped off, which it would if it was just a little bit of low-energy dust caught by the wind.

This tells me the glass was hit by high-energy sand particles, i.e. caught overspray from the blasting proper.  Sandblasting damages glass, and your contractor should've known that.  He has etched the glass (by roughening its surface, removing the gloss, which sandblasting does quite sincerely). I don't believe it can be recovered, and will need to be replaced.