Cleaning dried up hand-disinfectant from lacquered wood floor There was some hand-disinfectant dropped on a lacquered wooden floor. Tried to remove as much as possible with a wet tissue but the stains shown in the picture remained...
Anyone knows what could be used to remove these effectively?

I think you're going to have to sand and refinish the floor, or at least a portion of it.

Hand sanitizer contains a high concentration of alcohol which is a good solvent for many types of wood coatings inclulding lacquer. The portions that appear white look as though some or all of the finish has been cleaned off.  No additional "removal" is going to remove that since the problem is that the finish has been removed.

With a floor like this you may be able to sand and refinish only a section by using the natural lines and different wood tones to your advantage to choose an area that can be refinished vs. doing the entire floor.


How to best repair the tile My plumber had to knock out some of my bathroom wall tile to access the stack and make a repair. I am trying to go about repairing the hole. However I cannot separate the tile from the existing wall board. I believe they used some sort of adhesive wall board because I am not encountering thinset. Should I just cut all the way through along the grout lines and butt the new cement board up to the existing wall. I would be unable to tape those joints then. What is the best way to go about the repair? Attached is a picture of the main area of the repair. Note this is on the opposite wall of the shower and does not get direct water exposure.

Your plan is sound. Cut the damaged tile out along grout lines, being very careful to not chip the tiles that will remain.

Install new framing backing where possible, using construction adhesive to bond the original substrate to the lumber. Then, when you install your new backer, everything will be tied together well and taping the joint won't be necessary.


How can I tell if something is ruptured inside my lawnmower? My lawnmower got thrown into a rolloff container by mistake. When I went to dig it out, it was upside down and when I tipped it right-side up, all sorts of black liquid (I assume oil?) came spilling out:

Is it toasted? Any way to salvage or tell if something got broken or ruptured?

Should be OK
Whenever you change the oil, you have to tip it anyway to get the old oil out.

Your going to have to let it sit for a little bit, might be hard to start up at first and smoke a good bit whenever it does start, but it'll be fine.

Flip it up so you can see under the deck, make sure the blade isn't loose. Just grab it and move up and down.

Right there on the front make sure the spark plug wire is pushed on the spark plug nice and tight, you may want to remove the spark plug and wipe off the oil, dip it in a small cup of gas to clean it off. If it is really bad grab a new one (2-3 dollars maybe?)

The air filter might be bad, it's probably on the left under a black cover.
Should be one screw to remove the cover, pull the filter out. If it is soaked with oil throw it away. You can buy a new one for a few bucks - just go to a store that sales lawn boy and give them the model # of your mower.

Read the book and see how much oil it takes - finish draining the rest of that oil (tip it so it drains out, preferable in a bowl or container and dispose of properly) and fill it back up with new oil.

You should be fine after that, if there is gas left in it of course.


How can I install laminate flooring without removing base molding? I am looking for a suggestion about not removing my base molding and laying laminate under it. It will be much easier than removing because of risk of damage ,etc. , and I will put 1/4'' or 1/2'' corner round on top which I think looks good. Basically the molding is about 1/2'' thick. So I am wanting to go under that and 1/4'' from wall so how can I get that spacing and get it out after I get to the other side since it would be underneath ? I know I could just start it flush with molding since I am going to put round over on top but when I am hammering all the other pieces how do I keep it from sliding underneath and right against wall?

Pick yourself up a laminate flooring installation kit, like this one.

It comes with spacers that can be placed between the already installed planks, and the base molding. The spacers will maintain the required gap, as you hammer the planks together.

The kit also includes a pull bar, and tapping block. Both of which will come in quite handy.

Installing laminate (and any hardwood flooring) without removing the base molding is quite common.


Should I (can I?) temporarily unmount breaker box to drywall behind? My electrical panel is mounted on plywood which is secured by 4 nails into a stud and the top 2x4.
I want to drywall this last bit of wall.  Can I pull those nails and temporarily prop the panel on something while I drywall?  Do I need an electrician?  Should I leave it alone and drywall around it?  What should I do?

It's probably also secured by nails behind the panel.

Actually, you don't want to do that.  That plywood has an important utility purpose, it's where the power, phone and other utilities attach.  You need it.

The one thing I would do is extend the plywood to span out to the joists.   Feel free to lift up the cables and paint under them, might be hard to tell it's not drywall.  Don't paint the cables, it's important to be able to read their markings.  It's utility area, it's supposed to look ugly.


Why is it safe to use 15 A receptacles on a 20 A circuit? OK, the one answer I got was way off target, and another commenter couldn't figure out what I was asking, so I'm restating the question...

Are 15A 3-prong grounded outlets actually rated to 20A, allowing them to be used on 20A circuits? And if so, why, when the outlet can never be asked to supply more than 15A by anything that would be plugged into it?

More info:

This question had a comment that 15A outlets were actually rated to 20A. However, by design, there is nothing that will plug into a 15A outlet that will draw more than 15A. An appliance that draws more than 15 amps would have a "T-blade" plug that wouldn't go into a standard 15A outlet.

In addition, outlets are always wired in parallel, meaning that a 15A outlet would never have to transmit the amperage draw of a "downstream" outlet; you never "daisy-chain" outlets by connecting hot to neutral, for a number of reasons.

So, there is AFAIK no situation in which a 15A receptacle would ever have to handle more than 15A, even if installed on a 12AWG, 20A-breaker circuit.

If all the above is true, why would a 15A receptacle even have to be rated to 20A?

A 15A outlet is rated for 15A, with a 20A pass through. That is to say that the 20A circuit is in continuance throughout the circuit, however the receptacle itself (the contacts) are rated for 15A continuosly. Any single appliance with a 15A plug will not normally draw more than 80% of 15A, or 12A. The total circuit draw (multiple appliances - same circuit) can be 20A before the breaker trips.

A 20A breaker used with 12awg wire can feed multiple 15A outlets, one example is the kitchen. The reasoning is so that today's demanding appliances, which draw more current, can be used with a 20A breaker without the worry of nuisance tripping. If more than a total of 20A were to be drawn from the circuit, the breaker will trip.

It should be noted that any circuit that is intended to be 20A must use a 20A recepticle.

If the appliance were using 15A, it will be safe with the 20A breaker ( @ 80% = 16A). If it were to short, it will trip the 20A breaker just as it would a 15A breaker. A 15A receptacle can take 20A for a short time with no problem. The receptacle is overrated, otherwise it would blow up upon a short. A short circuit in actuality can be hundreds of amps in a very short duration. The breaker and receptacle are rated as "Time overcurrent" meaning it can take a lot of current for extremely short durations, and will trip on lesser currents that occur for a longer time.

An example one can relate to (refer to chart): Joe plugs in two electric heaters in his family room. Everything works fine until 20-100 seconds later the breaker trips! Joe overloaded his 20A circuit, by drawing 40A! The breaker will allow this overload for a short time. If the overload were bigger, say 60A the breaker would trip faster from 10-35 seconds. If the trip was due to a direct short, the breaker will trip Immediately. Breakers actually have a "Load characteristic curve" that you can tell when it will trip in time vs current.


Wiring requirement for small kitchen I am in the process of renovating an older home where I require just two or three counter top receptacles. I discovered in the NEC that:

  The countertop receptacle outlets in kitchens must be supplied by no
  fewer than two small-appliance branch circuits.

Unless I am mistaken, it seems that this requirement primarily pertains to counter top receptacles. Considering the limited electrical requirements of the kitchen, would I still need two circuits for the two or three counter top receptacles that I am to install? Additionally, there is a wall outlet on the opposite corner of the kitchen as the L-shaped counter top and it is branched off of the living room circuit which doesn't have much connected to it. Is this a code violation?

Looking at the actual code...

National Electrical Code 2014
Chapter 2 Wiring and Protection
Article 210 Branch Circuits
210.11 Branch Circuits Required.
(C) Dwelling Units.
(1) Small-Appliance Branch Circuits. In addition to the number of branch circuits required by other parts of this section, two or more 20-ampere small-appliance branch circuits shall be provided for all receptacle outlets specified by 210.52(B)
210.52 Dwelling Unit Receptacle Outlets.
(B) Small Appliances.
(1) Receptacle Outlets Served. In the kitchen, pantry, breakfast room, dining room, or similar area of a dwelling unit, the two or more 20-ampere small-appliance branch circuits required by 210.11(C)(1) shall serve all wall and floor receptacle outlets covered by 210.52(A), all countertop outlets covered by 210.52(C), and receptacle outlets for refrigeration equipment.
(3) Kitchen Receptacle Requirements. Receptacles installed in a kitchen to serve countertop surfaces shall be supplied by not fewer than two small-appliance branch circuits, either or both of which shall also be permitted to supply receptacle outlets in the same kitchen and in other rooms specified in 210.52(B)(1). Additional small appliance branch circuits shall be permitted to supply receptacle outlets in the kitchen and other rooms specified in 210.52(B)(1). No small-appliance branch circuit shall serve more than one kitchen.

The receptacles supplying the countertop, must be supplied by at least two 20 ampere circuits.  However, these two circuits can also supply receptacles in a "pantry, breakfast room, dining room, or similar area of a dwelling unit", as well as "receptacle outlets for refrigeration equipment". One of the more common ways to meet this code, is by splitting the duplex receptacles. One circuit powers the top outlet of the receptacle, while the other powers the bottom outlet. Another option is to supply the countertop receptacles with one circuit, and the refrigerator with a separate circuit.
As for the receptacle in the kitchen, supplied by the living room circuit. While this is likely not a violation. This receptacle does not count towards the two 20 ampere small appliance circuits required in the kitchen.


Trying to fix a leaky faucet, structure was not I expected after removing the knobs My faucet has been dripping very slightly, so I decided to try fixing it. I watched a couple of videos, and it seemed like the task would be fairly easy.

I removed the top of my handles, and what I found was unlike any of the videos I have seen Here is a picture.

https://i.imgur.com/BMqLMzQ.jpg

The base around it is fairly stuck, and there isn't any kind of valve that I can remove from the top. I did take this picture of the bottom, though.

https://i.imgur.com/7jk0Rx4.jpg

Does anybody have any advice? The base of the handle feels like it is stuck to the counter. Do I have to remove it? Do I need to remove something from below the counter in order to fix this type of faucet?

The base in the first photo will unscrew (counterclockwise). It will have to be removed in order to free the faucet base so it can drop through to the bottom. Check the base first for a recessed (set) screw that may keep it from loosening. Set screw can be loosened with a hex or slot driver.  The faucet base may not unscrew easily. In which case you should use either an  adjustable pair of pliers, pipe wrench or vise grip pliers. To prevent damaging the surface of the chrome base you can: wrap the jaws of the pliers with duct tape, wrap a rag around the base or do both.


How to repair a small hardwood crack? I have a maple bench that recently decide to crack. I'm not sure what's the cause. I'm guessing wood expansion due to humidity changes.  Anyway, I've decided to look around for solutions on fixing the crack. The crack itself is pretty small, a finger nail barely fits in the opening. Here's some pictures:

Top of the bench

Close-up of the top

Under the bench

Ideally, I would like to close the gap. In the end, I'm not sure which one is the best approach. I've considered the following:

Bowties; although it doesn't seems to close the gap.
Dutchman; a patch wouldn't be that bad, but requires a lot of precision!
Re-gluing; by carving the crack in a V shape from under the bench, adding glue and then clamping.
Wood filer; would probably require sanding the whole top, staining and varnishing again. I would like to avoid that.
Staining the crack with a tiny brush; makes the crack less visible but wouldn't close the gap.

Anyone have experiences on fixing these cracks?

UPDATE:
I went ahead and stained the crack as per @HenryJackson's answer.  It is a lot less visible.  I will leave it as-is for now.  (It's not making me crazy... yet!)

This looks like a crack caused by the wood drying and shrinking. Likely caused by dry winter air, although it's also possible that the wood wasn't properly dried before the bench was assembled. (Humidifying your whole house can help with cracks like this, but wood is a natural material and nothing will preserve it perfectly forever.)

It also doesn't help the way the bench is put together: ideally wood furniture should be capable of a little wood movement. When wood absorbs moisture it expands perpendicular to the grain; when it dries out it contracts perpendicular to the grain. (Wood also expands and contracts in the direction of the grain, but usually it is small enough to ignore.) The way this bench is constructed with that large surface of wood, there's no way for a little natural shrinkage without a crack like this.

Unless it's driving you crazy, my recommendation would be to stain the crack and then just leave it. You could try using pocket screws from underneath like HerrBag suggests, but if you try to close the crack tight there's a decent chance that you'll just get another crack somewhere else next winter when the wood shrinks again.

(I disagree with longneck's comment that this is caused by lack of structural support underneath: the crack probably happened next to the support because the support was holding the wood together and resisting shrinkage there. If you say it appeared in the middle of the night, that reinforces my suspicion.)


How to attach 10 AWG wire to LED strip lights? I'm running LED light strips from a location that is over 50 feet from the LED transformer. In order to account for voltage drop 10 AWG CL2 wire has been used.

Questions

Since the 10 AWG wire is so thick, what is the proper way to attach the red and black wires ( see pic ) to the led strips within an LED channel?
Is it code to pigtail a the 10 AWG wire to a 26 AWG wire within an LED channel. The 10 AWG wire is coming directly out of a wall. There's no room for a junction box at this point.
Would a butt connector be the most appropriate connector, in this case, do to the small size of the LED channel? If not what is an appropriate connector.

Use a pigtail from the 10AWG wire to the strip light connector:

(this is just a representative image, not sure if these will fit your strip lights)

Just use wire-nuts to connect the 10AWG wires to the wires that go to the strip light connectors. Or solder and tape them.

If you have strip light connectors that aren't pre-wired, then create short jumpers with suitably sized wire to plug into the connector.


What is this hollow box made of steel hanging on the ceiling? This guy is talking about resilient channel while he is playing with another thing, a hollow box pointed out by red arrow. What is that?

That's an electrical junction box. Likely for a ceiling light, but could also be for a ceiling fan, smoke detector, or anything else mounted on the ceiling that needs power attached.


Is it ok to pad a washing machine against the adjacent cabinetry? Not sure how to explain this.. have a new wash machine and it has to go under a counter in small space. The floor is in terrible condition (rotting old plyboard and cork), uneven and falling to bits, so did my best to level the machine. But it was still vibrating on spin.

So i just put some old dvd boxes between the sides of the machine and the counters next to it, effectively packing it in super tight.

Now it doesn't vibrate, even though its not perfectly level.

Question is, is this bad for the machine? Are they supposed to be allowed to vibrate their casing a bit? Or is it ok? Thanks. It's a magnetic drive bosch btw.

We had a washing machine vibrate violently when we tested it for the first time.
It turned out that it had these shipping bolts that was securing the drum. When we removed them the vibration stopped.

Check to see if youe machine has any shipping protection in place. If so follow the instructions to remove them.


Tub leaking at the supply line Today I tried to replace my tub faucet since the old one was dripping out of the front. The new one looks great! Unfortunately, it seems to drip at the supply pipe. The following picture shows the back of the tub, where the supply line connects.

I have circled where it is leaking--in between the ring which fastens the faucet to the tub and the part which connects the supply pipe to the faucet shank. It is leaking on both sides. Tightening the connection and adding more thread seal tape did not help. Any advice?

You (or someone) has used pipe thread couplings to adapt the 3/4" faucet inlet to those supply lines, this is not (IMO) the best practice.

Stainless braided flex supply lines with a 3/4" connector are available, specifically for your application. Decorative covers (generally called "shrouds") are also available with which to hide the supply lines if you don't like their look.

Specifications:
Overall Length: 37"
Rough-in Connection: 1/2"
Faucet Connection: 3/4"
Braided Stainless Steel


Why does water appear just below my basement slab in one location and not another? We recently purchased a house and inherited a "5 gallon lowes bucket shoved into a hole with gravel" sump pit. It sits approximately halfway across the width of our basement. There is consistently water in it 12 inches down from the slab. The water level rises and falls with rainfall/seasons, doesn't appear to be any sort of water leak. If I pump it to empty, it immediately returns to where it was before. Okay, cool, water table is 12 inches down, got it.

I finally got the motivation to dig a larger sump pit in the corner under the front side of our basement, in one of the lowest points I measured in basement. It's around 20 feet away from the current bucket-pump. I dug 35 inches down. No water. As I write this there's still water 12 inches from slab in old spot, no water 35 inches down from slab in new spot. There's no drain tiles or anything leading to the old spot, and the ground is like dirt, not particularly clay-like. Does gravity not exist under my house? Is the first pit like, supersaturated or something and acting as a mini-pond that's collected during rainy season?

I hope someone has the answer, it's driving me crazy!

Yes, gravity exists under your house and I’m pretty sure Sir Isaac Newton would agree, but I don’t think he could explain this...

But here are some ideas: 1) a small underground spring, 2) a bearing wall between the two locations, 3) Major addition separates areas

1) Because there’s different soil conditions at the two locations, it makes me think the original builder knew of a small spring and installed some gravel and a discharge pipe. The pipe is located about 12” down so the water never gets too high.

I’d check around your house and see if a pipe extends to a ditch, street gutter, etc. (Follow the roof drains too.)

2) If your house has a major wall separating the two areas, it could be keeping moisture from infiltrating your new hole.

3) Likewise, a major addition could have added a new foundation area, which is separate from the wet area.

I’ll check with Newton and see if he has revised any of his theories regarding basements...and then get back to you.


How do I remove mildew from walls and ceilings? My bathroom has some mildew on the walls and ceilings, and I desperately want to get rid of it. How can I remove it?

Fill a spray bottle with one part bleach, 9 parts water.  Wear gloves and then spray the walls with the solution, let sit for a minute and then wipe with the sponge.


Will roof work done by unlicensed volunteers pass code? I go to a church in Chicago that needs a new roof for one of their facilities. For my own home, I can sign a Certificate of Responsibility where it is my job to insure that all the work is up to code, etc. However, as a private citizen who would volunteer for this; I'm not bonded, licensed or insured in anything.

Will any work done by unlicensed volunteers pass code? Is it even OK for a group of volunteers to do roof work on a church? Do I have to be, or need a licensed contractor on site, to do roofs? Since the church is a public building, do different rules apply? Do I have to follow commercial code here?

I'd appreciate any suggestions towards something I may have missed, things that I might 'get away with' or be eligible for, because it is a church.

You are going to have to call your local city hall.  They will tell you if you need to pull permits and what checks there are.

As for "roofing" - there is no roofing certification so in theory anyone can put a roof up.  The church's insurance might not like this but if the city signs off on it or doesn't care than put up the roof.

I would highly suggest that you get a local roofing company and let them know of your situation.  Most would be willing to take on a smaller profit for having a foreman out to a site with many volunteers.

I am not sure what the height and slope of the church is though.  With a steep peak this might not be doable.  Just a lot of variables here.  And you don't want someone getting hurt and there being no church left.


Loosen the lower element on a electric water heater Help!!!! I have diagnosed that the lower element has to be replaced on my electric water heater. I bought the tool suggested to lossen and remove the element. It won't BUDGE!!!! Any ideas???

I believe the tool you are using is a plumbers socket. It is usually sized at 1 1/8th inch. The reason the heating element isn't removing easily is probably due to hard water build up on its threads. What I do when I encounter a stubborn heating element is to apply extra leverage to the socket. If you can supplement a cheater bar with the socket handle the element should unscrew with no effort. A 1/2 inch diameter steel pipe fitted over the handle will work. Or any object that will extend the socket handle several inches will also suffice.


PVC lubricant for pipe and fittings What kind of lubricant can I use on PVC pipe and fittings so that I can assemble and disassemble easily.  This is a stage made of PVC pipe that must be assembled and disassembled repeatedly.

Plumber's silicone grease.

Silicone Faucet Grease helps reduce friction and provides long-lasting lubrication. The grease is water resilient and oxidation resistant.  Resistant to most harsh chemicals
Retains its consistency in temperatures from 40 to 400 F.


4A circuit breaker for a refrigerator? I live in Pakistan and we have no electric panel or separate wires for different devices. I am going to rewire my house but before that I wanted to secure the refrigerator wire. I've been reading everywhere that there should be a 20A circuit breaker for the dedicated refrigerator line so I went to an electrical shop and asked him to give me a 20A breaker for it. He said that 20A is too high and I should get a 4A circuit breaker for it. We have a 220-240 single phase coming to our house. My refrigerator's nominal current is 1.25A (200W). The circuit wire is 7/0.29mm. I tried to object saying the breaker would keep tripping because its a big one but he said that he has been using the same breaker for his own big size refrigerator so it will work. Eventually I ended up buying it and attaching the refrigerator phase wire with it. Its been 3 days but still it hasn't tripped. So I want to know is it safe with this amp breaker? Why do we need a 20Amp breaker for it when 4Amp is working just fine?

Commonwealth countries normally use British standards in electrical wiring. For household wiring, there will be two distinct outlet from the distribution/circuit breaker board. One is 6A lines for the lighting circuits, and another one is 20A lines for all power outlet sockets. Lighting circuits are wired using 1.25 millimeter squared wires and the power outlet wires are 2.5 millimeter squared copper cross section area.

So, what you might have read from the internet is, anything connected or plugged in to the outlet socket is protected by the 20amp breakers. These breakers are rated actually to protect the wires in the house wiring, not to protect the appliances plugged to the sockets.

Properly rated fuse is already attached in your appliance power plug or embedded in its internal wiring. The 200Watts chiller is definitely consumes less than one ampere nominal current and its startup current may be three times higher, no way a 20Amps breaker will protect it unless it fully burnt and melt down.


How should this vintage wall-mount sink be mounted? Does not fit standard cast iron brackets I'm planning to wall-mount a vintage 'Standard' victorian cast iron sink similar to the one in this question: Antique Cast Iron Sink Wall Mounting Support and Weight Issues?. That sink has two bolt points high on the sink through the porcelain; this sink has two bolt points / mounting tabs low on the sink.

There is a vertical stud centered exactly where I'd like to hang the sink. The wall is completely open in this area, so horizontal studs can easily be added.

There are 4 mounting tabs and brackets. Two on the rear against the wall, and one on each side. Ideally, I would like to mount the sink using only the two rear tabs bolted to the wall.

The standard cast iron brackets available for vintage sinks do not seem designed for this sink's brackets. The pockets are not deep enough for the tabs on my sink, the holes do not align, etc.

My initial thought is to use two heavy duty lag screws + washers through the rear tabs into horizontal studs in the wall. However, due to the geometry of this sink, it seems like that might not work. The tabs are low on the sink, not high near the top lip. And there is no lower structure below that point touching the wall to resist a downward force against the front lip.

This would seem to make the sink top heavy, prone to tipping forward either due to the weight of the sink or from someone putting weight on the front lip.

But perhaps I'm underestimating the strength of lag screws?

The other Issue I foresee is the "lip" that pushes the very top of the sink away from the wall. My solution would be to mount a 2x4 or similar piece of wood to the horizontal mounting studs, pushing the bolt locations away from the wall enough to clear the lip. But I do not want a 2x4 visible on the wall behind my sink, and I'm worried that if I "hide" a small piece of wood completely behind the sink that the bolts will not have enough spacing to the edge of the 2x4 (if that makes sense). Would something like a thick metal washer make more sense than wood?

Are two lag screws a viable way to mount this sink? If not, how should I mount it?

I am certain that if you mount that sink to the wall using only the two holes in the tabs, no matter how strong the mounting screws nor how hard the backing, the cast iron tabs will snap off.

In the worst case, the tabs will hold the sink in place for days or even weeks, then break suddenly when you are barefoot in your underwear and the sink is full of soapy water and a wet cat.

Don't even think about using this exquisite antique until you have figured out how to construct supports between the front mounts and the wall.

Other than the thickness of the backing board, you have a lot of freedom to determine dimensions. The backing board should extend downward as far as conveniently possible to spread the levering force. Using the backing board also allows you to position the sink without regard to the wall studs.

The screws and bolts that pass through the sink should be as large as will fit thru the holes, not only for strength but to avoid lateral motion.

Here is a rough sketch of a possible installation:


How can I get old copy of NEC? How can I get an older version of the NEC (National Electrical Code) online for free? Specifically, I need a copy of the “1975 NEC”. I could get it on Amazon for $29, but I’d rather not pay that much for it if I don’t have to. Or I could get the “Guide to the 1975 Electrical Code” for $9 (which I probably will get). I already checked to see if I could check out the physical book at my library. But it is not available. I also tried to find where it is published online so that I can just simply print out the pages that I need. But no luck.

You can purchase a used copy of the 1975 NEC starting at $7.18 at Amazon:

1975 NEC at Amazon


What breaker configuration does my new on-demand water heater need? I purchased a on demand water heater.my old heater is hooked to a 20 amp breaker(see photo). Do I change out old breaker to a double-pole 60 amp breaker or do I have to move connection to a different breaker?

I don't know what a "double pull" breaker is.  There is single and double POLE, and single and double THROW switches (that aren't actually breakers but resemble them - used in transfer switches), but not 'pull'.

The breaker marked HW is the right side of a tandem breaker and the left side is the washer (presumably washing machine not dishwasher).  It is, in short, a single POLE double THROW breaker.  (Although not really - it's actually two SPST switches on a single breaker I believe)

What this means is that there are two different lines coming off this one breaker, running two different appliances.  It is 110V and can never provide more than 110v.

IT IS NOT OK TO REPLACE THIS WITH A 60A.

In order to run a 60A line to an on demand water heater you must put in a 220V, double pole single throw breaker which can feed 220V with 2 hot lines to the new on demand heater.

So yes, you must move to a new spot - and in fact you must move to TWO spots that are adjacent, in order to get the 220v 60A you need.


How can I remove/reattach the clamp on a dishwasher hose? I'm trying to fit a dishwasher into our kitchen. There is a small gap in a counter top for the hose to go through, and the part of the hose that connects to the tap is too big to fit through... Is there some way I can disconnect and then reattach the fitting?

Here's a photo of two pipes with the fittings I can't get off:

Here's a photo of the hole I'm trying to get this pipe through (with the pipe alongside for size):

The irony of this is that I know I did this before as the dishwasher was plumbed in previously, but I can't remember how :(

Perhaps you can detach the board (assuming it isn't glued but screwed in place), put the pipe in place and re-attach the board over the pipes?


How can I turn on a vent fan over a gas range when gas flow is detected? We recently installed a kitchen island and for various reasons there are no acceptable places to put a vent switch close at hand.

I would like to make the whole system more automatic and link the vent to gas flow.  (with an additional manual switch in a less convenient location)

I'm having trouble finding an appropriate device that could switch on my vent fan when the smallest single burner on the stove is running.

So far I'm looking at something like this:
https://www.alliedelec.com/product/dwyer-instruments/v6epb-b-s-1-b/70408848/

But I'm not sure if it's appropriate.   It seems to be intended for things like detecting if a boiler is running, and this use should be very similar, but my minimum flow may be smaller.

Has anyone ever heard of such a construct?   Is there a purpose built product I'm missing?

The switch linked in the question (Dwyer model V6EPB-B-S-1-B) won't work because its actuation requirements are too high. From its data sheet, actuation-deactuation flow rates for air in SCFM for the 1/2" pipe size valve are 6.50/5.00. (I'm presuming that they'll be similar for a non-air gas, ie fuel gas.)

An article at hunker.com asserts that "In most cases, all burners on the stove adjust down to about 1,000 BTUs" but also states "a low flame on the stove may only use 400 BTUs even though the burner might have an 18,000 BTU capacity." That's a little inconsistent but it's a place to start. There's no time unit specified but typically Btu is per hour.

The FAQs at eia.gov indicate that "In 2018, the U.S. annual average heat content of natural gas for the residential, commercial, industrial, and transportation sectors was about 1,036 Btu per cubic foot."

Combining these typical numbers, we estimate that a large gas burner of 18,000 Btu/hr will result in a flow of 18000/1036/60 = 0.29 cubic feet per minute. That's significantly below the V6EPB-B-S-1-B thresholds. The low-flow model V6EPB-B-S-LF actuates as low as 0.18, so it could detect the burner at high flow, but it wouldn't stand a chance if the burner were turned down to 400 Btu/hr.

Perhaps you could consider sensing something else such as heat or light from the flame. Or latch the fan on automatically when the gas igniter is energized, and use the more distant switch to turn the fan off when it is no longer wanted.


How to improve the drainage of a patio with 6"x6"x39" cement blocks used for edging? The patio looks like in the picture. I have no idea if this is standard practice but it looks dumb to me. There is a very small space between blocks and that is filled with dirt. Virtually the patio holds the water in heavy rain when the runn off water should go over the edge of a graded patio. I am wondering what would be the best way to improve the situation. I am thinking about drilling holes like below, one per block. I have no idea how easy it is. The other option would be to enlarge the spaces between the blocks.
The cement blocks are beveled, the maximum diameter of a hole can be 0.5"

Drain holes aren't a practical solution here. If you insist on drilling them, you'll need a high powered impact drill with a concrete bit, then you either have to dig a trench on the outside to get the drill positioned parallel to the ground or pry up the concrete so you can drill above ground. At that point, you're still going to have a maintenance chore as those holes will clog up. In the winter, they may fill with water, freeze, and crack the concrete.

As such, I'd highly recommend just getting rid of the concrete. It's a poor design to begin with. Not sure what the original builder was thinking by putting that lip on it. Unless maybe the goal was to use it as an ice rink in the winter? :)

As it's not a monolithic slab of concrete, but in separate blocks/pieces, you may get away with just removing a couple piece at the low end of the patio to act as a funnel to allow the water to run off from that one spot. You may have to dig a dry well or something to accept that amount of concentrated water, though. I think it'd be better to remove them all instead.


Novice Generator Interlock Kit Question Bear with me. I am preparing for a future blackout. I did some research and am hiring an electrician. For my knowledge, could someone help me understand if i'm incorrect here.

I purchased 2 Pulsar PG4000ISR Inverter Generators hoping to run in parallel with interlock kit with inlet socket to power certain circuits in my house. Is this doable? Or would i be better off getting a generator with a 120/240v twist lock plug?

I do not have any 240v appliances in my house or would power. In this  example would the Pulsar generators work as mentioned? In parallel it would supply around 6500 - 7000 watts on a single 30 amp breaker for me to divide amongst the main panel?

If you are planning to use a generator just for an emergency situation at your house. You are better of purchasing a residential type of genset.

If you are trying to save money and only want use the generator for something other than a residential emergency supply. Then you should go with just the standard portable generator. However, your input into your residence is regulated by the 240V twist lock, which is protected by an overload and may not even be the rating of the twist lock. So you may not be getting the full KW of the genset.

Unless you have a reason for needing an inverter then there is no reason to spend the extra money on them.


Fire proofing walls with Aluminum Foil Tape I am currently trying to fire proof my reptile room which consists of racks that are ran with heat cable.  I'm worried that a rodent may chew through the heat cable and cause a fire.

I'm looking to add 2-layers of 5/8" Type-X fire-rated drywall and in addition use Scotch 3M 3326 Aluminum Foil Tape which has a temperature range of -20 to ~ 250°F.

Is there anything I'm missing that might make it a terribly bad idea to run Aluminum Foil tape up and down the walls all around?

Thanks!

The type-X drywall is a great idea as it is a great barrier to reduce heat transmission to combustible materials beneath, thereby increasing the amount of time it would take for the underlying materials to ignite when exposed to fire conditions. Use drywall tape and mud to finish the joints and call it good. As @Tester101 suggests, aluminum foil will do very little at structure fire temperatures, in fact I would bet the tape adhesive would catch fire and the tape would melt.


Replacing Load bearing wall in basement So we are fully gutted in our duplex and we realized that the middle wall of the building (load bearing) is set on railroad ties that apparently lay on dirt. We noticed this when trying to assess why the floors were slanted toward the middle of the building. I would like to remove that wall, remove the railroad ties, pour a footer and then replace wall with either posts or a new wall. I want to explain my plan and see if anyone spots any problems with it.
We are planning to build temporary walls on both sides of basement between 36 and 40” away from middle wall. These walls will be 2x6 studs 16 o.c with a 2x8 or 2x10 bottom plate to help disperse weight (floor is dirt) we will then remove the middle wall and footer ties, dig down approx 18” and pour a new solid footer 18” deep 18” wide by the length of the house (42’)
Is there any justice to pouring a footing under our temp walls?
My only concern is while digging for the new footer we start to underpin the temp walls, that is why we are going 36” off the wall to hopefully avoid that.
The home is balloon framed with a stick built gable roof that sits on the outside walls so I believe there is no roof load on the middle wall, only floor loads.

Ambitious project with lots of issues: 1) loads on walls, 2) temporary supports, 3) size of new bearing wall, 4) connections, 5) soil conditions, 6) size of footing,

1) I’d verify that the roof does not sit on the wall. If it does, it makes things more complicated, but not impossible. Is this a single story house? Is it located in (a.) high wind area, (b.) seismic area, or (c.) high snow load area,???

2) I like your plan of having two temporary walls...is this due to joists lapping on the bearing wall? Keeping each temporary wall about 3’ from the bearing wall is reasonable. Remember, the transfer of load into the soil is at a 45 degree angle. That is to say, the transfer of loads from the temporary wall should not impact the soil (and edges of you 18” wide trench) 3’ away. (We’ll talk about the width of your footing later.)

3) If the new bearing wall will only be 8’ or 9’ high, then 2x4 studs at 16” oc are acceptable. Will it sit on the subfloor or is that balloon framed also?

4) How the new bearing wall is framed will determine how it’s connected to the footing and ceiling (above).

5) The type of soil will determine the size of the footing, required reinforcing (rebar), likelihood of sluffing, etc.

6) I like the continuous footing idea, but it may need to be wider. (Going from a timber width to 18” seems reasonable, but if we knew more about the type of soil and total load, we could determine if it’s wide enough to support all the loads.

So, to answer your question, no, I don’t see any major problem, but if you could answer the above questions, we could help more.

Btw, a few pictures of the attic, etc. would help.


Origins of drain flies in apt? We live in an upscale relatively small and new building in suburbs of NY. It’s a 2bdrm. I and my husband keep it exceptionally clean —trash taken out near daily, sweeping-mopping-vacuuming done every other day, no food is ever left out, no dishes ever left in sink but placed into dishwasher immediately, any spills taken care of, etc.

Despite all this, for the last 2 months, we have had about 3 dozen flies hover above each of our three sinks (kitchen+each of two bathrooms)

Building pest control has come by and treated sinks and surrounding area last Tue by pouring pesticides down the drains. No improvements. Above each sink there is a constant swarm of flies. Pest control said they will treat once a week until the problem is resolved.

My husband and I are wondering: are the pest control people diagnosing and treating the problem correctly? What could be causing this?

Check your houseplants. It sounds like they are gnats that live in overly moist soil. Look for fungus in the soil and if you find them, decrease watering and treat with a solution of neem oil to get rid of them.


Can I convert my oven to a four prong? I live outside of Chicago, and my house has older wiring.  The wiring to the kitchen oven is armored cable with two hot conductors and a neutral.  My wiring system uses the metal sheathing of the AC as a grounding conductor.  I want to convert my current three prong plug to a four prong one.  Is it safe and within code to use the AC sheathing for a 60 amp circuit?  I thought I read somewhere that 20 amps is the limit.

My second question is: Is the grounding hole in in a 50 amp plug bonded to the surrounding metal plate like in a 15 amp plug? So, if the metal plate is connected to my metal box, which is grounded through the AC sheathing, I don't need a jumper cable from the back of the plug to the box, right?  The plug I bought is a Lengrand 3894CC6 and here's a couple of pics.  Thanks.

You'll need to use a 10AWG ground pigtail here

For a flush mounted box, NEC 250.146 and in particular 250.146(B) form the controlling Code on how to ground the device(s) inside:

  250.146 Connecting Receptacle Grounding Terminal to Box.
  An equipment bonding jumper shall be used to connect the
  grounding terminal of a grounding-type receptacle to a grounded box unless grounded as in 250.146(A) through (D). The
  equipment bonding jumper shall be sized in accordance with
  Table 250.122 based on the rating of the overcurrent device
  protecting the circuit conductors.

.
.
.

  (B) Contact Devices or Yokes. Contact devices or yokes
  designed and listed as self-grounding shall be permitted in
  conjunction with the supporting screws to establish equipment
  bonding between the device yoke and flush-type boxes.

Since your receptacle does not have a self-grounding clip on the mounting yoke (I know of no receptacles >20A that do, even), you will need to use a bare or green 10AWG copper wire from the receptacle ground terminal to a 10-32 screw in the designated grounding hole on the back of the box.  This will ground the yoke, faceplate, and receptacle grounding terminal, without relying on the receptacle mounting screws as a grounding path.

As to that sheathing...

Since this is an existing run of cable, and the straight NEC does not limit the ampacity for which AC sheathing can be used as a ground path, I would use this sheathing as a ground, considering the obvious alternative (NEMA 10) is quite a bit worse here.  There is also the option of running a 10AWG bare copper wire back to the panel or grounding electrode conductor/system by any route possible to serve as a retrofit ground conductor as per NEC 250.130(C).

(The subpoints to NEC 250.118(8) you mention are Chicago-area specific amendments to the NEC.)


Mystery pipes in basement - where do they go? Newbie to the forum here. Will upload photos this evening, but thought I'd start with the question/context:

Just bought a fixer upper farmhouse in Portland, OR area. House is at least 1930s, could be older (long story). We also don't know if it was originally post and beam with foundation added later, but it's safe to assume that the house's sewer connection was only added in the late 40s/early 50s when the surrounding farm land became a neighborhood.

The house sits on half crawlspace, half unfinished basement. In the basement area, the sewer line leaves the foundation approx. two feet up the wall, then runs approx. 19 feet to the sewer main. A sewer scope has shown this line to be clean. There's an exterior clean-out, but the plumber couldn't find it.

Back inside, there is also a basement floor drain (below the sewer outtake). It appears to be old galvanized, and does not have a p-trap bypass. To me, this suggests it's not sewer, but after sucking with a shop-vac over the pipe opening it certainly smelled like sewer. I poured ~1 gallon of water down the hole and it drained well. There is a lot of visible debris, though.

Additionally, there are two 2" PVC pipes that drop vertically into the floor of the basement (again, below the sewer outtake). One is a drain for both the bathroom sink (upstairs) and the washer (in basement); the other appears to be a vent (goes up through the floor), but am still trying to determine. There is no sump/sewer pump in the basement.

One last detail: public records of the local sewer system indicate that my property has two sewer laterals. I have no idea where the second one goes, but it appears to be further away from the house.

My question(s), then: Is it possible the floor drain and 2" PVC pipes connect to the main sewer line out of the house? Aside from scoping them (the original scope didn't inspect these), is there an easy way to find out? Alternatively, could they go to the second mystery sewer lateral, or to a drywell?

Thanks everyone, apologies for the novel.

Thanks everyone for the feedback and tips! Turns out I was able to get a clear answer by calling the sewer company:

1) They looked at their recent scopes and confirmed that our property does indeed have two sewer laterals. They also observed some corrosion and decided to come out and take a look.

2) They brought a truck out to our house and performed a sewer scope - entering from the manhole immediately downstream and running upstream to where our laterals connects to the main line.

3) They then had me run water from every fixture in the house, one after the other. Turns out that all fixtures run to one lateral, confirming that our basement pipes do indeed tie into it somewhere out in the yard. The sewer guys theorized that what the inspector mistook for an exterior cleanout was actually the basement pipes tying in! Our second lateral is "inactive," but is likely an old stormwater drain for our back patio...which may or may not be legal.

Thanks again for the suggestions. Glad we got this mystery figured out! Now to determine how old this place is (we have aerial photos proving the home was there prior to the build date on tax records)...


Gledhill 450 Torrent RE What is the top pipe connected to my Gledhill Torrent 450 RE thermal store?

It comes out of the very top of the tank. Not on the side but right on the top in the centre?

Looking at the installation and service manual, it appears to run to a feed and expansion tank to allow the water in your system to expand and contract safely as it heats and cools.


Plaster in contact with hot wires The house we are working on has an outlet missing the plug in part so it is hot! My mother decided to put plaster right onto the hot wire! At first I didn't really pay attention or think about what she did! However, I'm now feeling like my house is going to go up in flames before we even get to move in due to her actions! What do I do? Is it OK that she did that can I stop worrying or should I call fire department and have them undo her mistake before my house burns?

First off the fire department won't help you until there is a fire. They don't do electrical work.

The circuit breaker that feeds that wire should be shut off until the receptacle is replaced or the problem is corrected. If the receptacle is to be eliminated the wires should be capped off and a blank plate should be put on the box.

If you, or your partner, are not comfortable doing electrical work, you should call an experienced electrician to correct this and any other electrical problems in the house.

Good luck on your project!


Diagnose cause of voltage fluctuation in house Background

My house has 100 amp service with all copper wiring and all wiring contains a hot, neutral and ground wire.
The past three weeks the lights in the house go dim and bright.  The fridge makes a little noise when the voltage drops/spikes.  It happens sporadically and some days it won't happen at all, other days it happens frequently throughout the day (no pattern to the time between occurrences).
The load doesn't seem to affect when this happens.
When the problem first appeared I started checking the voltage on the panel.   When it happens one leg will drop down to around 118 volts for a few seconds,  when it typically stays around 122 volts.   One time one leg spiked to 169 volts.
As i'm writing this message the fluctuation in voltage has happened at least five times,  no load change in the house has occurred over that timeframe.

What I have done

I had an electrician come check the panel and verify I have no loose neutrals.  He said the power company is to blame.  He checked out the panel and didn't find any issues.  Unfortunately the spike / lowering of voltage didn't happen while he was here.   I called power company.

Here is how my visits w/ power company has gone:

Visit #1:  Technician comes out, checks voltage at meter.  Monitors voltage for a few minutes, no problems arise then leaves.   Declares no problems on their end.

I start watching the neighbors house to see if they are getting any power fluctuations.  I notice it is happening for them also.  I speak with the neighbor and they claim it has been happening for months to them.  They thought it was wiring in their house.  Unfortunately they are renters and they can't be counted on for any help.

Visit #2:  Technician comes out,  I'm home this time.  He monitors voltage and has me put load on the system.   Everything checks out,  nothing happening.  I tell him neighbors experiencing same issue.   He says not seeing anything, will do a 'line trace' in a few days.
Visit #3: Three technicians come out they check voltage at my meter, let it run for awhile.  they check neighbors meter, find neighbor has issue in the meter and they fix the issue.   They still don't see anything happening at my meter.

They say the transformer is relatively new and say it can't be the problem.   As they are walking around the poles and other houses,  I look at the volt meter they have installed at my meter and it drops down to 118 volts.  I mention this to technician and he says that shouldn't happen.

I ask one of the technicians if something was going out in my neighbor's house could that impact my voltage?   I said they have been running their AC all the time. He said it should have a thermal overload and not cause any issues w/ other neighbor's electricity, but he has seen where things fail and it can cause issues.

Technician's leave saying these things can take time and need to be patient.

What to do next?

I'm far from an expert on this,  so any help is appreciated.   I don't want voltage fluctuations harming things in the house.

Could something in my house be going bad which is causing the issue?  Should I start turning off circuits in the house and see if the problem occurs?  Would that be one way to troubleshoot the issue?

I'm afraid the burden of proof is on me now regarding the power company.

120v is supplied as two "legs" of 240v.  In a perfect world, loads would be balanced and neutral would not be required.   Neutral is there to assure the midpoint stays the midpoint even if the two legs are not balanced (and they are almost always not balanced).

A couple of volts of drift is no big deal, and is a normal and healthy effect of uneven loading on the legs (you could reduce it by using extra thick wire, but then you're wasting money).

However, tens of volts of drift says the neutral is not doing its job, you have an open neutral or lost neutral.  This means balance is a matter of luck, and most of the time some appliances will see less than 120V while others see more than 120V, which is likely to damage the appliance and even start a fire.

240V loads such as oven, water heater, installed A/C unit, electric-car charger, heat pump, installed electric heat or electric dryer, will have no effect whatsoever on a neutral problem.

The fact that neighbors are also having the problem helps.   What would help the most is if you have some sort of data-logging system actually recording leg voltages over an extended length of time.   Significant shifts in leg voltage (I don't mean 2 volts) would absolutely reveal a damaged or lost neutral.


Advice for replacement/repair of an HVAC with a cracked heat exchanger? My townhouse has a downflow 1994 Rheem 2.5 ton HVAC unit on its roof (combines both A/C and heat). We have had two issues with the unit and have been in the townhouse for a little under two years. In this latest case, the contractor noticed there was a crack in the heat exchanger of the unit, requiring him by law to shut off the gas and electricity to the unit. His recommendation was to replace the unit completely, in that the amount of labor spent on this and future repair work would overshoot the cost of complete replacement.

I am liable to agree with the recommendation of the contractor, but wanted to ask and see if there was anything out of the ordinary I should be aware in considering the HVAC unit's replacement?

Check your unit's warranty. The heat exchangers on some units are warranteed for 20 years or longer. You may be able to get at least some money from the manufacturer, or a credit toward a new unit of the same brand. They may also cover all or part of the installation labor.
Find out whether there are any federal or state tax incentives that could help. A federal tax credit has been available in the last few years for improving your home's energy efficiency, and replacing an older heating unit with a higher efficiency model was one way you could qualify. I don't know if that's still available in 2012, but worth looking.
Your local utility may also offer some sort of incentive for installing a high efficiency unit (not to mention the lower monthly bills).
Some utilities have programs like this one, where you can save money on your electric bill by letting the utility reduce your energy usage during peak periods. (In simple language, that means they'll turn off your air conditioning for short periods on very hot days to help avoid brownouts.) This probably won't affect your choice of a new unit, but it's something that you might want to consider at the same time.


What happens when there is no heat demand? What happens when there is no heat demand? By heat demand I mean there is no demand for space heating or domestic hot water. Is the water inside the pipes still flowing? Is this why bypass valves exist?

I am trying to characterise the output of a condensing boiler(s) (connected in series) which are generating the heat demand required by a sum of apartment blocks. I have assumed that each apartment flat has a Heat Interface Unit. I know how to calculate the required flow rate to each HIU when there is heat demand. However, I don't know what happens when there is no demand to an apartment. Is there water still flowing to the HIU but bypassing inside the unit? What happens to the return temperature of the bypassing unit?

In a normal hot water system heat demand triggers a main circulating pump and a zone valve or zone pump.

Without demand, heat can slowly migrate through the pipes by the laws of thermodynamics.

This migration can be stopped by the zone valve or a zone pump with a built in check valve.

Hope this helps your thought process.


LED GU10 lights come on randomly I have 2 new GU10 lights in a circuit controlled by an electronic dimmer (they are dimmable LEDs). They come on at random times at irregular intervals. I've had other LEDs that have worked ok, it's only happened with these new ones. They are FEIT electric that I got from CostCo

I'm assuming your dimmer is rated for LED, ideally with a neutral wire?  LED dimming is a morass of conflicting quasi-standards, and a lot of LED makers cut shortcuts by calling themselves "dimming" but only working with certain modern dimming methods.

Old style dimmers are made for incandescent only - they don't have a neutral wire, and power themselves by flowing a small amount of current through the circuit at all times.  Incandescents don't care (the current is too little to make them light up). But for LEDs, what happens really depends on how well the LED is engineered for working in old-style dimmers.

And LEDs do list the types of dimmers they're compatible with, on their data sheet.

But beware Feit Electric, Lights of America, or Utilitech.  Those are "bottom shelf" duff brands made to hit a price-point.  Here's the problem with that: The LED emitters are solid.  But they require an electronic driver circuit to translate 120V into constant-current to drive the LED.  When they must shave costs to hit their price-point, there are many ways to cut corners on that driver circuit, and most of them add up to dramatically shorter life, for instance by using cheap electrolytic capacitors.  Also, they cut functions like the ability to "dim" well.

Done properly, LEDs are a 30 year bulb. I've never had an LED fail except for a Lights of America.  I also have 18 years of experience with CFLs and yeah, only the bottom shelf ones fail there too. I get 10 years of service out of the others.

Try brands like Cree, GE, Philips, Sylvania.  They're not much more expensive if you shop around.


Can I create a false ceiling using XPS board instead of gypsum board? I want to install a false ceiling on the top floor in the classrooms of a school.

I have installed a grid structure and now, instead of using gypsum boards, I want to use XPS insulation boards of 1" and more.

My question is: how can we putty-paint those boards so they give an aesthetic look to the classroom?

XPS must be covered with drywall or another fire resistant material.  XPS, when exposed to heat will put off toxic fumes and will melt.  The last thing you want in a class room is molten foam melting onto students in the event of a fire.

Stick with proper ceiling tiles, drywall or another suitable material.  What you are proposing would be against most building codes that I know of, at least in North America.


How can I prevent my refrigerator door from hitting the wall? I have a stainless steel counter-depth refrigerator door (LG LFXC24726S).  The right wall sticks out a bit further than the frame, and if the right door swings too far, it hits the wall and will eventually chip itself, and/or scratch the door - two outcomes I want to avoid.

Per the photos, I have placed three small clear rubber bumps between the door and the wall, but

they look ugly
they keep shifting, so I'd have to glue them in place

I need to find a solution that is not visually intrusive, but creates a good barrier.  One solution I considered was somehow adjusting the door's swing radius to prevent it from reaching the wall, but I don't believe that can be done with this model (perhaps I am wrong).

Alternately, I need some form of bumper, but I don't quite know what to search on/for.  I'd prefer something clear that won't scratch the door.  I suspect some sort of 4-5 inch long clear rubber corner wrap would work, but I wouldn't even know what to call it to identify it, let alone know where to obtain one (ostensibly, "the internet" once I know what to search for).

Ultimately, aside from the non-starter suggestion of removing this piece of wall, how should I prevent the door from hitting the corner?

Bumpers Detail. Click for full size image

Open Door Detail. Click for full size image

Whirlpool French door started  hitting the new Silestone countertop a few months after the remodel. Dont think the part failed—probably it is due to our 100 year old house tilting. I have just installed high gauss magnets in the upper door hinge and they work perfectly.


Water base , oil baed or shellac primer on old plaster wall I would like to use latex paint to on old plaster walls in a 1800's house. Some of the walls had to be patched with new plaster where the old plaster was removed down to the lathe. There appears they have been coated with calcimine before being wallpapered I searched the internet on which primer to use before latex and now I'm totally confused. Should I use oil, water based, shellac or Zinser Guardz?

You absolutely cannot beat the shellac primer. If you go this route, get Zinsser BIN. It will cover pretty much anything and stick to pretty much anything. The drawback is the cost, at around US$45/gal it ain't cheap. This stuff uses alcohol as the primary solvent, so you might want to get a respirator that is rated properly to filter ethanol (or maybe not, but don't drive after you use it...). This can be used in most sprayers directly out of the can, it's quite thin.

The oil based (like original Kilz) is good too, and a lot cheaper. It's also harder to apply, very thick and prone to brush marks. And it puts off some powerful fumes (so does Shellac, but that is NOTHING compared to Kilz, which uses some more noxious solvents that will make your eyes water). Oil based primer is going to stick to most existing surfaces. This will not work in some sprayers as it is too thick, even after thinning (assuming you only thin it as much as the manufacturer suggests).

Latex is probably the cheapest option, and also the least flexible. It's a bit easier to apply than Kilz. but not as easy as shellac. You shouldn't need a respirator to use it, though. Latex is only suitable for application over existing Latex. If there is any doubt, don't use latex, there is a chance you'll regret it. I've seen badly applied latex where you could cut a small hole in the paint, and actually slide your hand up and behind the dried paint, lifting a large section right off the wall.

In all cases, make sure you scrub the walls before you do anything. This is extremely important if you are painting after removing wallpaper, because it is necessary to get all of the old paste off the walls. TSP is the best cleaner, but it's not environmentally friendly. The TSP-substitute is almost as good. 80% of the work is in prep; slapping paint on the wall is the easy part.


Staining a 130 year old pine floor So.. we decided to rip up carpet and plywood to find original planks (pine) in one of the third floor rooms in our 1880 home.  Fast forward to save you on reading.. I applied a penetrating oil based minwax stain (dark walnut)..

the floor looks pretty good considering the shape it was in when we started (tried to upload pics but wasn’t working).

The stain has been let to dry for about 4 days now (90° and 80%hum)..  we brushed the oil on and wiped it as we went..

Here’s the question.. to the touch the floor feels dry across the room.  If I rub a q-tip on the floor, there is some coloring on the q-tip.. is this normal? Does this mean the stain is still wet?

After dealing with the oil/smell/drying time, I really want to get this room done, but don’t want to rush the water based polyurethane before the stain dries obviously.

There is a good possibility that the pine boards in a 130 year old house are very dense wood. Old growth timber from that time was quite different from what we experience as "pine" today. As such that type of wood is much less absorbent than even some types of hardwood that you may choose today. The dense wood leaves more of the stain material on the surface as opposed to penetrating and thus longer to dry.

As case in point I used Minwax stain on some oak shelves I built recently. I wanted to use the shelves with just the stained surface without applying a shiny sealer like polyurethane. It took a good 10 days before the stain was completely dry. And that was in west coast spring weather. Such stain in 90° and 80% humidity could very well take longer to fully dry.


My artesian well just ran dry. Do I just wait for it to fill up? I have been living in my current house for about 8 months now, and this is the first time I have been without water(besides power outages). I noticed that the water was a bit brown so I let the hose run thinking it would flush the muddy water out. I forgot about the hose and ran the well dry. The hose was only running for a few hours. Is there anything I can do? I am guessing I will just have to wait for the well to fill up again. It should be noted that the last couple of days we were putting on multiple loads of laudry, far more than normal.

The short answer is, depending on the source of the water table, it should fill back up over time.
But there are many reasons, other than you leaving the hose on for a day, why your well can run dry.
Are there any new building developments in the area?
Is your region suffering from low rain or snow fall this year?
Or, if there's excessive rain/snowfall, your well could have filled up with excess silt, effectively clogging your well pump.


Can I reduce dryer vent through basement wall? Can I reduce my 4" solid dryer vent pipe to a 3" at the outlet, my foundation has only 3 1/2 " opening between floor and concrete to cut through.

This picture shows where the vent to outside will go. To the right is an existing bath fan vent. I would like to place the dryer vent on the same wall.

You can probably convert to a rectangular vent that equals the cross-sectional area of a 4" duct. You may have to get creative. The area of a 4" circle is about 12.5 inches square, so 3 by 5 would do, for example.

I would not reduce the area (as with a 3" round vent) as you'll increase backpressure and create a lint trap.


Vapor barrier above a frequently wet crawlspace? How can I create a vapor barrier between my home and its crawlspace which frequently has standing rain water that must evaporate and drain?  Some first floor rooms have smelled damp for years.  I am renovating the home, so now is the time to fix this.

My house on Long Beach Island in New Jersey is built on a man-made land mass crossed by lagoons.  The water table is only a foot below the surface of the packed silt soil.  After a rain storm, the vented crawlspace has standing water which takes a few days to evaporate and soak into the damp soil.

Most of the crawlspace floor is loosely covered with old plastic sheeting.  Kraft faced insulation hung between the floor joists, but I removed it after Hurricane Sandy flooding ruined it.  I found holes and gaps in the plywood subfloor for wires, pipes, and even a large hole beneath the tub drain.

How can I create a vapor barrier between this wet crawlspace and the plywood subfloor?  How can I fill the various sized subfloor holes around the electrical wires and copper pipes?  I will be creating a plywood box around the tub drain, but should I insulate it?  Before I install bedroom carpeting, can I install a vapor barrier on top of the subfloor?

I will make a separate post about the damp smelling rooms.  Thank you for your input.

I think you have to do whatever it takes to keep that water from pooling under there. French drains, dry wells, sump pumps, etc. You can't have that standing water there and not expect mildew smells to get into the house. After the water is mitigated, you need to have the crawlspace sealed, and dehumidified.


Unable to find stud in shared wall I was thinking about mounting some ikea besta cabinets on a shared wall in my house (1997ish construction, weird town house thing that shares a wall with the neighbour, and there is an office down stairs).

I was having extreme difficulty finding any studs – and knocking on the wall was giving me weird results – I could find areas that don't sound hollow but they didn't seem to run vertically or horizontally, just 'square'ish areas of non-hollowness every ~60cm or so.

Confused, I took off one of the power outlets to take a look to see what was going on and I don't really know what to make of it.

The power outlets themselves are attached via metal brackets that go deep into the wall.

The other side of the shared wall appears to be brick. Then theres maybe 15-cm to my side, and the majority of it seems to be filled with some kinda concrete-ish stuff? I poked it and it was hard and its grey, thats about all I can say about it. Might just be some kind of sound deadening or fire proofing?

It was hard to take a photo of but I tried:

Anyone have any idea of what kind of construction this is? Is it just some kinda wood or metal bracket attached to the brick wall on the far side of the shared wall? What would I do to mount something to this – just stick to the 'solid' feeling squares? What would they even be made of? Or am I just out of luck?

The rest of the internal walls are pretty normal and I can find a stud reliably every 60cm.

Mounting the cabinets in this situation may well be a non-trivial construction project due to the lack of studs and the wall serving as fire separation between dwellings under the control of different occupants.

There are two ways to determine the construction in this case.

Locate accurate architectural plans depicting the original construction. Such plans may not be readily available.
Destructive investigation entailing opening the wall up and looking to see how it is built.

Irrespective of the method used to determine construction, the mounting of cabinets in the absence of studs requires an appropriate plan suitable for the actual construction. Whether such a plan will require a detailed design so that the cabinets are self supporting depends, of course, on the nature of the existing construction.

Alternatively to cabinets, furniture might by used to meet the functional requirements of the larger project.


Does live turf need insulation from roof heat? I'm installing grass turf on a rooftop in Jersey City.
It's a flat roof with a lot of sun exposure and occasional strong, swirling winds. I really feel like I need to pad beneath the turf to protect from the heat of the roof, am I correct here? If so, how do I do it?
As well as needing to adhere it i would  also need to be able to remove it when I move.

A major benefit of a grass/turf or otherwise "green plants" or "living" roof is that you don't have the heat of a typical roof in the sunshine. Storm Water management is an additional benefit to the municipality. Both can result in significant financial incentives/tax breaks as a result.
"Needing to remove it when you move" sounds dubious - this is not a temporary thing easily rolled up and taken away, at least if it's done right. If you don't own the roof, it's unwise to get into this, and if you do own the roof, you sell the green roof with the building (or condo, I guess.)


Trying to find a replacement door handle/knob I bought a house, and two of the closets are missing the door handle/knob.  It's a mortise lock (old house), and every other interior door in the house has the same handle, so I'd like to not get one of those glass ones that seem widely available and instead get a matching replacement for consistency throughout the house.

I've browsed dozens of pages on amazon, Schlage, Baldwin, etc.

This is the hardware kit.  The only part missing is the handle:

Here is a door with the missing handle:

Looks close enough to me (buy two, do both sides). Also, consider swapping a new one with the inner knob from one of the closets or any other less conspicuous door. If you don't like this one, search Google (not suppliers) with these key words:

Beaded Oval Door Knob: (rejuvenation.com)


Does the NEC allow EMT to act as ground? I'm considering running EMT through my shop for outlets, etc.  Does the NEC allow me to use EMT as ground (i.e. no need for ground wire)?
A related question: I may run wire through the shop's attic to get to the other side.  This wire will not need conduit (NEC specifies wire must be protected if it is in a "high risk" area).  Can I transition from EMT to 12/2 wire inside the attic, then transition back to EMT on the other side?  I'm guessing I could use either a three-strand cable or just staple individual THHN wires along either the ceiling joists or rafters.

NEC recognizes steel conduit as ground. One recently active ignorant inspector does not change code, unless you have the same ignorant inspector and opt not to fight them.
You can choose to transition to NM cable in the attic (ground wire connected to the steel box at each end of the cable), though I would not recommend that (I've seen far to many gnawed-bare NM cables to trust them in likely rodent habitat) but you absolutely cannot "staple up THHN wires" without conduit around them. While it may not matter for your application, you are also then limited to the 60C column for wire derate, and if it's a hot attic that might impact you.


How can I switch between a dishwasher and a 2 gallon undercounter water heater on same circuit? Our water heater is a long way from the kitchen, and we waste a lot of water waiting for hot water to the sink.  There is a 20a circuit breaker that powers the dishwasher and disposer.  The dishwasher will continue to use the hot water from the main water heater.  We would like to add a 2 gallon undercounter water heater to our hot water pipe - rated 1500W.  Is there anything I can buy that will not allow the water heater to run when the dishwasher is on?  The water heater is just for small tasks, but there is not enough power to run both at the same time.

You could run the power to the dishwasher and disposal through a current sensor and contacts on the sensor in series with a  coil on a relay. The power to the water heater could be taped ahead of the sensor, and connected through "normally closed" contacts on the relay. When current is detected in the sensor the contacts on the sensor would close, energizing the coil on the relay opening the N.C. contacts, breaking power to the water heater.


Is it better to vertically or horizontally stack two TV antennas to get stations from opposite directions? If I had two (identical) Yagi antennas, and wanted to point them in different directions to get stations from opposite sides of my location, would there be any advantages to mounting them both (vertically) on the same mast, as opposed to side-by-side on the roof?

I'm not stacking them in order to get better gain; I just want to pick up additional channels from two separate directions.

It depends on the polarization of the signal.

If you're unsure about the polarization of the signal, look at the antenna elements of a stationary yagi antenna to see if they're horizontal or vertical. Mobile antenna are often just a single vertical element, so it's not a foolproof way to tell. An internet search would also work.

TV is horizontally polarized.

For horizontally polarized signals, vertically on the same mast, spaced at least 1 wavelength apart would be ideal to prevent most signal attenuation.

For vertically polarized signals, use separate masts, spaced at least 1 wavelength apart would be ideal to prevent most signal attenuation.


Refrigerator won't cool I have a Danby mini fridge I bought used off Craigslist about 9 months ago. It's worked great until about a week ago when it suddenly stopped cooling at all (both fridge and freezer compartments). Now when I plug it in, it clicks every minute or two, and I don't hear any humming like I would expect from a fridge. Also, the compressor gets uncomfortably hot to the touch after being plugged in for a couple hours.

I pulled the relay off the compressor and shook it; I didn't hear any noise from it. It hasn't been laid down recently. I have a multimeter and can test different parts if I need to. I haven't taken off the interior rear panel to inspect anything yet.

What is the most likely cause of these symptoms?

Test the compressor
Your compressor is going to look something like this

To test the windings, you'll first have to remove the "box" where the wires connect.
WARNING: There's likely a capacitor in here. Take care not to let the capacitor discharge into you.

Once you've go that out of the way, you should see three pins/terminals.  They'll typically be arranged in a triangular pattern.

One terminal will be start, one will be run, and the other will be common. To determine if the windings are still good, you'll simply test the resistance between each terminal.

Set your multimeter to read ohms.
Touch one probe to each of the bottom pins.
Write down the reading.
Touch one probe to the lower left pin, and the other to the upper pin.
Write down the reading.
Touch one probe to the lower right pin, and the other to the upper pin.
Write down the reading.

NOTE: Your readings may vary.
You should end up with something like this.

This tells me that the top pin is common, the lower left is start, and the lower right is run. It also tells me the compressor is still good. The reading from start, to run should always be the largest reading. The readings between start and common, and run and common should total up to the reading from start to run.
If the values are way off, or you get infinite resistance between the pins, replace the compressor.
If the compressor checks out, you'll want to make sure it's getting power.
Check the power to the compressor
After reassembling the compressor, plug the refrigerator back in. Set the refrigerator to a setting that should cause the compressor to come on. Using a multimeter set to volts AC (VAC), carefully probe the two wires connected to the compressor.  You should measure ~120 volts.
If you get the proper reading, you'll likely have to replace the relay and/or capacitor. If you don't get ~120 V, the problem is in the control circuitry.
Mechanical failure
If everything checks out, there's still the possibility that the compressor is seized. In which case, you'll have to replace the compressor.


What caused my toilet's flapper valve to become spongy and disintegrate (see pictures)? I just had the flapper valve fail one of my home's toilets.  The rubber had become spongy, sticky, and was beginning to disintegrate.  It's so soft now that it rubs off with the slightest touch.

The valve was installed by the previous homeowner, so I don't know its history.  However, since I've moved in, this toilet has been very seldom used.  It's in the "guest" bathroom, and unfortunately have guests over now who are inconvenienced.

I'd like to understand what happened here, so I can avoid something like this happening again.

Flapper valves in my bathrooms typically last about 2 1/2 years of so. Depending upon the type of material they either get mushy like the ones that you show or they start to get hard and no longer make a good seal. Since I do not add anything to the toilet water tank like a disinfectant or fragrant additive I have to attribute the degradation of the flappers to the water chemistry and the chlorine that the city adds to the water.

Flapper valves are relatively inexpensive and the type you show in your pictures only take a few minutes to replace.


NM cable from wall box to dishwaster I need to connect my dishwasher to an electrical box in the wall under the sink but it is recessed so the cable must come out through the front plate and not side knockouts. Out of the same box will also be coming a similar cable but for the garbage disposal. The wall box is a regular metal handy box, 2.5x4 or something like that.

Is it okay to have two 14/2 NM cables coming out of the front plate of an electrical box and be basically exposed inside an enclosure (sink cabinet) on its way to the appliance? Should I get a coverplate that has two knockouts through which I would fit two NM cables fitted with clamp connectors?

You should not run NM sheathed cable through a cabinet that has doors which open to allow storage.

You should be installing grounded receptacles and using appliance connector cords.


Can my garden furniture be saved? I have some hand me down wooden furniture. Unfortunately, with multiple moves and births in the last few years, it has gone a unloved.

The wood seems very weak, and is brittle when dry. One beam snapped when stood on by a small child.

My question is, can I save it? I will obviously have to replace the broken beam, but can I treat it so that it doesn't become firewood?

It sounds like the wood has already rotted or otherwise deteriorated beyond repair. If it is just a few pieces then you would need to replace those, but if the entire chair is rotted then it's likely destined for the scrap pile.

Generally speaking you need to finish the wood in order for it to hold up against the elements. Paint, shellac and varnish are some of the methods you could use.


Can I use extra wire from two separate cables to add a washing machine in a garage? I have two existing 12/3 NM-B cables that are used to connect two different circuits, which are distributed from a junction box close to the location I want to add a washing machine. The washing machine requires 12/2 wire, and a 20A fuse. Each of these existing 12/3 cables has a spare red wire. Can I use one of these red wires as neutral, and the other as load to the 20A fuse? Should I pull a new cable instead?

You should definitely pull a new cable for the washing machine circuit.

Problems with your solution

You can't use a red wire as a neutral (See NEC 200.6(A)).
Circuit conductors (wires) must be contained in the same "raceway, auxiliary gutter, cable tray, cablebus assembly, trench, cable, or cord" (See NEC 300.3(B)).
You have not clearly described where all the wires in the junction box come from/go to, or what else is on those circuits.  So there's no way to know for sure if it's possible to use them to power the washing machine.
Laundry branch circuits are not allowed to have any other outlets (See NEC 210.11(C)(2)).
Laundry outlets must be GFCI protected (See NEC 210.8(A)(10)).


Fix creeky old wooden floor The duplex I live in was built around the 1920s and still has the original wood floor but its very creeky and the neighbors downstairs are always complaining so I'd like to fix it.

I'm wondering if there is a way I could pull up some of the wood planks without damaging them so I can fix the problem underneath and put the wood back in place afterwards.  Or if there is a better solution.

Ive tried drilling screw but it hasnt helped.  And i mop the floor with polish every couple of weeks and for about a day the lubrication maxs the creeking lessen but only works for about a day.

My friend told me to try using sand.  He said that if I sweep sand all over the floor it will get into the cracks and act as padding to stop the creeking, but there isn't really much space between each plank so I'm doubtful that much sand will be able to work its way underneath the boards.  I'm going to try it later today though.

If you can locate your floor joists, you can use a longer, ~2-2.5" finish nail and nail both finish floor and subfloor to the joist. Once the subfloor is tightened down, you can spot nail the finish floor to the subfloor as needed. I did that in my 1928 house and it worked.


What to consider before removing a drop ceiling? My basement has a drop ceiling in a semi-finished part of it and we've removed many of the panels in the process of updating the house's wiring. With most of the panels off and clear view of how discolored and dusty they've become, we're thinking to remove the drop ceiling entirely and trash what's unusable or donate the panels and frame that are in tact.

Before we do so, I want to check what reasons there might be for keeping the drop ceiling and putting it all back together replacing damaged panels? I haven't been able to find a list like that though so I turn here.

We don't like the aesthetic or the materials, and we can use the extra couple inches of height we get. The joists showing above the drop ceiling are beautiful old beams, and we like seeing the utilities and guts of the house, making it easier to do maintenance as well. On the other hand, the house is drafty and on the 1st above ground floor, the wood floor is quite cold. Also very little sound insulation, and I know removing the drop ceiling won't help with that. Lastly, we'll probably rent the place out eventually, not sure if that has any influence on reasons to have drop ceiling or not.

Anything I'm missing? What should one consider before dropping a drop ceiling?

I think you understand the pros and cons, as you have listed them very well. However, if you’re considering renting the basement space out in the future, your number one complaint will be sound control: in both directions.

Removing the existing ceiling and exposing the joists, wires, etc. is a personal preference , but will allow you to add/move lights, add sound control, etc. in the future when you know more about what spaces are going to be used in the rental.

We just did this for a client, but painted the ceiling white. I think black on a low ceiling could feel “weighty”.


Pass CATV and ethernet over single ethernet wire I have a fiber-optic router which also outputs a CATV signal. CATV was unused previously (the service provider includes CATV in the pack but I've never used it before) so it was not taken into account when deciding a place for the router and the fiber-optic ingress to the house.
The room the router is at (and where the fiber-optic enters the house) doesn't have any coax cabling (no TV was put there, it's a "computer room").
Now I'm moving an old TV to a wall where I have a coax cable (TV/SAT) outlet and a ethernet outlet set up, and I want to set up DVB-C on that TV, coming from the router, and also ethernet LAN (for SmartTV related services)
The ethernet outlet on the "TV" has direct connection to a wall outlet near the router (so ethernet wouldn't be a problem), but the current TV/SAT coax outlet doesn't (and there's no easy way to cable it as it is now, those hoses go to a completely different direction and don't come near the "computer room").
So I'm wondering... is there any device I can use to pass the coax cable signal over ethernet? kind of like a MoCA system but the opposite (pass coax over ethernet, not ethernet over coax). Also, I'd need to keep the existing ethernet connection for IP. Not sure if such a thing exists, but that'd basically allow me to do what I need without having to run cables.
My option if that doesn't exist is to -try- and run (I'm not sure how polluted the conduit where the ethernet cable goes might be at some point, I didn't do the installation) a coax cable on the same conduit as the ethernet is in (have both cables in) and split it at the "router room" outlet: would that significantly affect ethernet data (using UTP cat-6 cable, not shielded) by running both on the same conduit? I don't really need that ethernet to be extremely fast (it's just for a FHD Smart TV) so some packet loss should be more thank ok.
There's a third option which would be adding a compatible wifi dongle to the TV and just replace the ethernet cable and wall outlet altogether for coax ones, but if I could avoid that, that'd be great.
I also don't have good experiences with wireless video transmitters (which would be another option), plus that'd also mean buying another STB for cable, which I want to avoid if possible (the TV already has a DVB-C tuner, which I suppose is what the router outputs through the CATV output)
I'm open to alternatives also which could be more work/cost effective than those presented. I'm extremely far from being an expert on these matters and there's surely something I haven't thought of

Based on this AVforum thread (from 2018), forwarding a coax-delivered TV/satellite signal over Ethernet isn't possible and if it were, it would probably be a bad idea anyway. Some relevant quotes in case the link dies:

Unlike say a HDMI signal you had previously which is just one signal albeit high bandwidth satellite signals are lots of different ones on the cable. Hence you use a satellite tuner to tune into the relevant frequency.
Sky Q uses a wideband LNB which has a frequency range of 230MHz to 2359MHz so not feasible to send all these signals this cables in a different manner down a CAT cable.I'm not certain what TV carrier the OP is using, but I believe the concept is similar no matter who the carrier is. --Ed

A good friend of mine is an aerial/satellite specialist and says it's not even a good idea to extend coax with more coax! Whenever there is a break in the copper joined by couplers or whatever, the impedance can change massively affecting signal quality. He doesn't even terminate to sockets and runs cable from LMB to Sky box because of these issues; he's been burned by this too many times.

Since it seems you have conduit in your walls, your best bet would be to pull a good quality coax cable (I believe RJ56 (or is it RJ59?) is the current "best") from the entry point in your house to as close to your use point as possible.
Both high-grade coax and Cat6 cables are well insulated against RF interference, and the Cat6 cables design even allows it to run next to power lines without picking up significant interference. (Note: it's still recommended to keep Ethernet cables away from power, but it's not critical in most use cases, and it's only a few inches.)


How can I smooth rough latex paint before repainting There are several rough areas in the latex paint in my bathroom.  I want to smooth them before repainting but I'm not sure how.  The finish is somewhat shiny (maybe semi-gloss, maybe eggshell).  When I've tried sanding latex paint in the past, it just turned to goo and clogged up the sand paper.  (The paint is recent enough that I'm confident there is no lead in it.)  I'd skim coat with wall compound but I'm afraid it won't stick to the shiny finish.  Stripping seems an extreme solution.  Any thoughts?

USG All Purpose joint compound sticks to shiny surfaces. you have to lightly sand the wall first only to prevent bubbling. All Purpose compound has glue in it. It stuck perfectly to my semi-gloss walls. I know this post is old but if anyone else comes by I wanted them to know. I got my information directly from USG


Bookshelf back reinforcement I was needing to reinforce 5 shelf bookcase that was leaning to one side and had sagging bookshelves. I had read about using 1/8 inch plywood/hardboard, but it seems to me that it would be too flimsy. Wouldn’t it need 1/4 inch material?It is leaning over a few inches based on how unlevel bottom set of doors are.

The backing doesn't need to be very thick to prevent the deformation (parallelogramming) you are seeing because it works by tension rather than compression. The edges of heavier backing would show more and require molding to cover them. Lay the shelf unit down on its front, square it up and use small brads or fine finish nails to attach the thin backing around the edges--top, bottom and both sides.

Sagging shelves are another matter. Are these shelves adjustable, say with pegs in holes? If so, you would have to stiffen the shelves on the front.

If the shelves are fixed to the sides, you would tack the backing to the individual shelves, this would help, but the front edges of the shelves might need stiffeners attached to the bottoms along the front edge, if the shelves are not made of stiff wood. These stiffeners would interfere with getting books in and out and limit the size of books that could be shelved. You could put stiffeners on one or two shelves and put the heavier books there.


Setting screws in concrete while it is still soft -how do I use epoxy in this case? Can I ? Should I? I am thinking about using Sonotubes and the adjustable post support shown below.
The idea is to rest the square with the screws on the sonotube to make sure the screws will be set with their heads level at the same depth and in vertical position.

Should I use epoxy? How do I apply it ? I want to make sure the screws do not rust a lot in time

Setting bolts in wet concrete is a standard practice, and using a board to hold them in place is a good idea.

You absolutely do not need any epoxy when setting into wet concrete. I don't know what effect that would have, but its certainly redundant. Epoxy is used when setting anchors into preexisting hard concrete which has been drilled.

Generally you wouldn't use regular hex-head bolts for this, you would use an actual anchor which would look something like this:

The bend prevents both pull-out & rotation once the concrete cures. These come in varying lengths depending on your application (eg 8, 10 inches) - but they are inexpensive so you can just err on the side of "bigger is better" assuming you have enough concrete depth (which in a post should not be a problem).

Where I live I think these are sometimes referred to as "J-bolts".