Drawer Slides for Wide Drawers I installed an island in our kitchen using two prebuilt 36" wide cabinet boxes from home depot. The cabinet's came with crummy drawer slides which I would like to upgrade; however, in my research I've discovered two potential problems. The first is that the drawers are very large and therefore will inevitably carry a lot of weight, so I'd ideally like to get heavy duty slides. The second is that the drawers are very wide. There is only ½" clearance on either side of the drawers for slides to fit into: I haven't been able to find slides which are rated for a lot of weight which are thinner than ¾". On top of that most of the side-mounted slides I have found on the internet specify that the max drawer width is 24". Will using such slides on a 36" wide drawer be a problem?

Are there specific slides I should look into that can handle a lot of weight and can fit with these cabinets? It seems like there are fewer dimensional restrictions with under-mounted slides but those can be expensive and don't seem to be as sturdy as the side-mounted style.

We only have two of these cabinets, so I don't mind spending a bit more for good-quality slides.

`There are many slides that will handle #75 to #100 lb of weights.  See one hereThese drawer slide weight over 1-1/4 # each and 2" in height.
  I believe your drawer  will be more an issue at 36 width than the slides. The drawer that comes with the cabinet will not hold very heavy weight. The pre-built bottom would be too light. I built drawer 36" deep and about 30" wide with 1/2 plywood for the bottom. My drawers were filled with dishes and quite heavy. I use heavy duty full extension slides that rated at least for 100#.


What is best way to crimp a 1/4 inch copper pipe I need to cut and seal off a 1/4 copper pipe (that contains a gas) so that it's air  tight.  I bought a crimping tool and a cutter.  I plan on heating the pipe, then using the crimping tool (which looks like vice grips) to pinch the pipe shut.  Next, I will cut it, pinch the end closed, then solder the end.  After that, I'll remove the crimping tool.  I'd like to do this without letting any of the gas out, or ai in.  Will heating the pipe before crimping it help the crimper to seal the pipe, or not? Any other tips that you can offer for this procedure?
Note: This is a hobby project, and the copper pipe contains acetone and a partial vacuum.  It's going to be a thermal engine (basically a giant "drinking bird")
More Directions.  First, I'm going to solder a valve onto the tube.  Then I am going to suck out all of the air in the tube with a vacuum pump, and close the valve.  Then I am going to open the valve to suck some acetone into the tube, closing the valve when needed.  Then I am going to crimp the pipe, cut off the valve, solder the pipe closed and remove the crimping tool.  It's important that I don't lose any of the acetone or vacuum during the final solder step.  Also, acetone is flammable and I am using a torch.  The crimp seal must be nearly perfect.

acetone is stable at typical soldering temperatures, so that sounds feasible,
I would anneal the tube first, clean and tin the inside, clean off the flux residue then fill and proceed as described.


How to run cable from attic inside an external brick wall? My exterior walls are brick. inside it's dry wall. My house was built in 1950.  I'm not sure what's between the drywall and brick but I'd like to fish a cable down from the attic to this wall where my TV is located.

I'd like to drill a hole through the attic down into the wall cavity and then down to a hole I will make in the drywall.

My concerns are, will there (should there) be any horizontal studs along this cavity? And what would you assume is behind the drywall (on an external wall made of brick) on a house built in 1949?

I've done this with interior walls before, but I don't know whats on the other side of an external facing wall.

Stud finder seemed to only have vertical slats

I would cut out a square the size of a single gang box in the drywall, at your target height and see what's behind.  Depending on what you find you can use a set of drill bit extensions until you hit the top plate, then you can pull the wire back down with the bit as a guide.

Worst case you find you can't do it and you can stick a low voltage, old work, box in its place and screw in a blank outlet cover.


Missing a strike plate in a metal/steel frame I live in a house that was built in the 1950s. The door frame was made of metal/steel. Since I noticed that the strike plate is missing, I'd like to install a new plate. My question is -- what kind of screws should I be using? Machine screws? If you look at the photo below, the mounting holes look like threaded holes. Thanks in advance.

Yes, metal frames use machine screws, not self-tapping screws.

I’d order a plastic “strike box dust cup” too.

Btw, those existing metal tabs with the screw holes in them are made to be adjusted slightly. I’d be careful moving them, because the screws may not align if you move them too much. However, if the flat head screws do not “seat” properly in the strike plate, you can adjust those tabs.


How can I get rid of gnats and other flies all over my house? We just moved to a new place and we're noticing that there is a lot of gnats and fruit fly type bugs all over the house!  We've been killing 2 or 3 an hour and they keep coming back.  We find them all over, not just in the kitchen.

Is there any tips, tricks, products to get rid of the pests?  I have a pregnant wife in the house, so harsh chemicals are a last result.

EDIT:

So... we just found the source of the flies...  I got home from work to fine a Haz-mat team cleaning out one of the townhomes we share a wall with.  Apparently the guy is a hoarder and had been hoarding things like empty whisky bottles and pizza boxes.  The team had found human waste on the walls and rotten food throughout the house.  The flies that were living there were so bad that the neighbor below him called the police about it.  We  only shared some pluming lines with him, they shared an air vent.  SO GROSS!!!

There are plenty of recommendations out there on the web, but I can't say how well they work.  I think the lifespan of a gnat is something along the lines of 15 days, so you basically just have to remove their food source, and they'll be gone in 2 weeks.

Clean dishes quickly, keep everything clean, get rid of potted plants (they feed on the manure found in many types of soil that you might get for potted plants) or cover the top layer of soil with an inch of sand to prevent them from getting to the manure, look for any dead animal bodies (rats, lizards, birds, etc.)

I've also seen ideas for traps, which supposedly work pretty well, but just because you catch some, that doesn't necessarily mean that you'll get rid of their breeding grounds.  The basic idea is that you take a cup and put 1" of vinegar and one drop of dish soap in it, then cover it with something that resembles a funnel (curl up a piece of paper into a cone shape and cut the tip off.)  They'll be able to fly in because the funnel will guide them downward, but they won't be able to get out so long as you seal between the lip of the glass and the funnel (maybe fold it back down on the outside of the glass and secure it with rubber bands.  Like this:


How do I properly ground my subpanel that only has one neutral/ground bar? I am adding a sub panel in an unattached building. My sub panel has the  connection for the 2 hot wires coming from the source panel (a 40 amp double breaker) In addition it has one neutral/ground bar which has a green screw head for the ground and a row of places to connect neutrals. I am seeing advice on sites like yours to not connect the ground wire on the same bar as the neutral. So with only one bar I am not sure what to do with my ground wires. Do I need to install a second ground bar? I have the ground wire coming from the house that is well grounded through the house 200 amp service as well as a buried ground rods outside of the outbuilding. Do I use both and if so do I connect them both to the same ground bar?

The neutral and ground MUST NOT be bonded at a sub-panel.  They should only be bonded at the main service panel.  If you bond them anywhere other than the main service, the neutral return current now has multiple paths, including though your ground wire.

You should be able to buy a second bar for the sub-panel if it really is meant to be used as a sub-panel.  The neutral bar will need to be isolated (it should have plastic insulator separating it from the case).  The ground bar should be bonded to the case.

The ground wire from the house must be connected to the sub-panel ground.  Since it is a detached building the ground rods are also required by code and should be tied to the sub-panel ground.  The ground to the service is the most important because it will provide the low resistance path back to the service in case of a fault.


Type of glue for sealing cable entries I am looking for the name of a type of glue (I think brand recommendations are not permitted, so not that) which will seal an electrical connector to the socket it is plugged into in a reversible and temporary manner. I've scraped this stuff off before and it is usually some form of yellowish translucent gum. The exact use case is sealing a USB plug to a waterproof USB solar-powered power pack (and the other end of the cable to the similarly waterproof thing I'm plugging it into), so this can be used outdoors.

Not what you are describing, but "duct seal" is a (all I've ever seen is gray) non-hardening putty intended for plugging conduits to prevent various things (air, water, rodents, insects) from coming along with the wires, usually at building penetration points. Find it where electrical supplies are sold, though it may not be all that obvious on the shelf.

It is removable and reusable.

What you are describing sounds more like hot glue (which could work, though its performance exposed to sunlight may be dubious.)


Looking for a current-actuated timer switch I have a drainage pump with a level sensor. I'd like to have some protection in case of failure of the level sensor, which would leave the pump running dry while I'm not around, eventually leading to pump failure.
Basically I'm looking for something like a timer switch, but rather than starting at a programmed time and running for e.g. 10 minutes, it should start the countdown once it detects enough current being drained (say > 1 A), and cut off the power supply if it's still draining > 1 A after 10 minutes.
Does anyone know of such a product?

What you want is a current transducer with a relay output.
I use these to stop motors driving conveyor belts if the drive chain or belt breaks the load drops the current transformer senses the drop and trips a relay. Stopping the motor
The ones I use are fairly expensive AcuAMP act200-10-s
0-10v output  0-100 amp range  96$
I know automation direct carries them I use these on small motors in about 20 places in the mill.
No interest in automation direct I use there products.
The sensor is adjusted for the load and when the pump runs dry the current drops and sets the output a relay is what I use to interrupt the motor.
This could be used but a low level high level setup would be cheaper and make more sense.
Edit added for another method of control.
you could just turn off for a delay then pulse the pump if current high it keeps running if still dry it would shutdown.


Uneven ceiling, best way to fix it? Contractor responsible for preparing the ceiling and painting, neglected to mention the ceiling for bathroom is visibly uneven. 7cm difference from one end to the other. Looks also a bit concave. The contractor said it's not his responsibility and blamed it on someone else. Said best way to fix it is buying trims to cover up the edges between wall and ceiling. And advised against tearing it down and starting again, waste of time and still might end up uneven. Is he right?

In many cases a ceiing in an older home if replaced needs to have an attic strongback installed to occomdate the new ceiling.  As a home shifts with settlement of ground and foundation the current strongbacks are compromised.  So when installing ned to old, the old ceiling joists need to be supported.  When the old drywall was removed, the old strongback releases pressure and caused the joists to shift.  So work must be done to the structure of the attic.  It is obvious that the strongbacks and the joists are drooping. Is it the drywall guys fault?  Yes and no.  He is not a structure contractor.  It is the General Contractors fault.  And if the home owner was the GC...it is the inexperience of the homeowner.  When you hire a finisher to repair problems, you have bad results.  In a court situation if you attempt to litigate, the finisher will win the suit as he is there to install the drywall to the existing structure only...He does not have the skills for anything else.


How can I prepare uneven concrete basement floor for vinyl planks? I have roughly 600 sq ft of basement that needs new flooring after some unfortunate flooding this past summer.  We had carpet over concrete and are now looking to lay vinyl planks down. There is about 150 sq ft off to the side (L-shaped basement) that is very uneven.

I'm a first time home owner, inexperienced with these types of jobs, and just trying to figure out the best way to approach this.

Do we try to level out the higher area only? Grind it down, or self leveling concrete? Or lay down a subfloor throughout the entire basement?

The majority of the floor is even, with one section that was possibly a crack in the foundation "repaired" by a previous owner. Max variation is nearly 1/4" in some spots around the edge of that patch. They had laid some ugly VCT over top to try and hide it.

And yes, the water problem has since been solved. And if it makes a difference, the area that has the raised patch is not the area we had water issues.

Any advice is greatly appreciated!

Type of flooring dictates how "perfect" it needs to be, carpet being the least work. Vinyl is flexible so just no real drastic changes.

Below are the basic steps to fixing uneven concrete floors.

Use a straight edge and mark high and low spots. (Really exaggerated case in this image)

Or if you like gadgets, Bosch has a new laser out that lets you easily mark the uneven parts.

You use a grinder (with dust mask and safety goggles) for high spots. You can rent a large floor grinder or get on your hands and knees.

and SLC (self-leveling compound) in low spots. For SLC just follow the manufacturer's instructions. If the floor is really bad you may want to pour the stuff over the whole thing.


How can I temporarily fix a cracked bathroom sink? Last night I managed to drop something onto my bathroom sink, which now has a large crack in it and is obviously leaking when I turn the tap on. I know I will have to replace the sink, but I cant really afford that at the minute.

Is there something I can maybe put into the sink that will hook over the sides so the water drains into that and down the plughole instead of directly in the sink basin?

You can probably fill the crack with epoxy to stop the leak.  It might not look great but it will do the job.

Make sure the area is clean and dry, and that you follow the directions on the packaging.  If there is any chipping make sure to brush away any loose debris so that the epoxy will bond correctly.

As far as what type of epoxy to use, Home Depot carries a Marine Epoxy which they describe as:

  Marine Epoxy is a permanent, waterproof adhesive. The 2-part formula is ideal for projects requiring high bonding strength on surfaces exposed to water immersion. The adhesive can be applied and will cure underwater. It can be used on glass, metal, wood and other common materials.

This sounds like it would work well for your application.


Tape vs screw joining 4" duct When joining 4" round duct, like for fart fans or dryers, is it sufficient to just use sealant and aluminum tape but no screw or should I be using screws also? It seems that the tape alone would be good enough for this relatively low duty function.

Tape is not a mechanical fastener. It is a sealant. It is not acceptable as a way of connecting duct. The options are screws, hose clamps or zip ties depending on temperature.

I have used hose clamps to connect all the metal duct on my dryer exhaust. For the bathroom fan it will be a combination of screws and zip ties as there will be some insulated flex duct.

Also when sealing ducts you may only use one method of sealant either mastic or tape. You can't use both. They aren't rated or listed for use together.


helping with sprinkler conundrum I would like some suggestions on how to solve this issue. My end goal is to add a zone for my garden area. Below is my rough drawing. I'm trying to avoid having to dig from my current manifold box to the garden area. The second picture is what I'm looking to do.

The red zone which is zone 4, I'm wondering If I can turn that into a water mainline take that red zone all the way to Box 2 and remove the T for 4 sprinklers in zone 4. Currently, there is no Box 2 but I can add one there. Then attach the previous zone 4 sprinklers into the new manifold? could that work?

Or I could take Zone 4 into box2 and add an additional manifold. Then I would have to turn on zone 4 in order for other zones in box 2 work. Could I do that?

My Controller has room for 8 zones and I can run the additional wires to box2.

Yes, it's a fine idea to add another valve and manifold location and to convert that long section of red so that it's an always-on main line rather than just a zone 2 feeder.

Your desire to add a separate zone for the garden, rather than make the lawn zone water the garden too, is a good one for several reasons. For example, gardens and turf grass have different watering requirements; and broadcast watering over the garden wastes water and supports growth of weeds all over the garden.

When running wire to the new valve location remember that you need a conductor for every valve, plus one as a common, plus one or two spares for when "it would be nice if..." happens later. ;-)


High humidity in bathroom! I cannot for the life of me figure out where this excess moisture is coming from. My bathroom has humidity about 10% higher then the rest of the apartment. The living area is fine. I check the humidity on a Humidity monitor and it is always very high in the bathroom, around 68%
The thing is its only 30% humidity outside so its not coming from outside. I have a fan that I use every shower and leave the door open. If I open the window it drops to about 58% (that is with the outside being 30%) It won't get lower then 58. As soon as I shut the window it goes back to 68 or so. I see no leaks under sink, no condensation on toilet. I don't know where this is coming from. I live on the 2nd floor of a 3 floor apartment complex that is only 2 years old. I have lived on the 2nd floor of a 3 floor complex before and never had this problem. And that bathroom didn't even have a window. This one does. I don't get it. Can someone tell my why it is so humid? What gives?

Definitely get the Landlord involved. Unless there's a standing pool of water, much bigger than the toilet, there's no apparent nor logical reason for any room to stay so noticeably different.

I'd say maybe a backdraft through the exhaust fan from a faulty damper, but you've disproven that. In the meantime, check with the neighbors & see if either are doing anything strange or noticed the same thing.

I'd suspect the 1st floor got a Hot Tub or started Indoor Gardening. A Room Humidifier or Air Conditioning System's Humidifier wouldn't even do anything like your saying.


GFCI Outlet wired to non GFCI. Can I switch? I have a GFCI  outlet that is wired to another non GfCI outlet. So when either has a problem, they will trip off. My question. Can I reverse these outlets?   Let's say the GFCI outlet is on my left and the non-GFCI outlet is on my right, can I switch them and put the non-GFCI outlet on my left and the GFCI outlet on my right?

The physical location of the two devices does not matter, it's just how the GFCI is wired. If you wire a GFCI one way, it'll protect every receptacle after it - if you wire it another, it'll only protect itself. If you simply want the GFCI to only protect itself, then just switch the wiring and leave it where it's at. However, if you'd like it to be in that new location and still only protect itself, then you can switch them and just wire it correctly.

However, there could be a reason behind why the plain receptacle downstream is protected. If it's in a location that, by code, should be protected; then it should be protected. If you don't like them both flipping at the same time however, then you could flip the wiring as shown in the above image and get a second GFCI receptacle and wire it in where the plain receptacle is now.

Again though, like the comments mentioned, if it's supposed to be GFCI protected and you're constantly having them flip.. I'd recommend putting in a second GFCI.


Reduce vibration by bench grinder I live on the 2nd story. I would like to reduce the vibration caused by the bench grinder. I bought the grinder at least 30 years ago. Everything is original equipment. I have some carpet padding under it, but a lot of vibration is still transmitted to my floor.

Can you suggest some other ideas that will preferably cost the least.

Thanks.

Typically the only thing that will cause the vibration on grinder wheels like yours, are the wheels themselves being out of balance. My suggestion would be to get two new wheels (grinding stones).


Why does a steel door frame for drywall have a double return/backend Title pretty much says it all, but here is a picture just in case:

I think it has to do with the wall achors but I can't find a definitive answer.

Just to clarify: steel frames for masonry walls only have a single return/backend.

Stiffness is one reason, but not exactly in the way that was mentioned above. That return will prevent waviness as viewed from the room.

Also, raw edges are ugly, even if they return into the wall. They're difficult to caulk, too, as there's no real bond surface--the caulk just falls behind if there's a gap.


Can I tile directly over Artex? The entire of my bathroom is covered in artex and I'm planning on tiling over all of this—the entire room, not just the bath/shower area. The texture of the artex is very slight and 90% is only =< 1mm. A few areas are about 2mm but no more than that.

The general consensus seems to be not to tile over artex at all. I should either remove the stuff or board over it.

The artex is pretty old so I'm worried it may be asbestos based and I don't really want to try removing it or sanding it down—it sounds like a horrible job regardless of any asbestos.

Having to board over it with aquaboard or something similar will probably mean having to move the bath etc and I'm limited on time and budget so if possible tiling directly over the artex will be much easier for me.

Although the general consensus seems to be not to tile over the artex, I have seen people suggest it should be ok if the texture is less than around 2mm (including the guy at one of my local tile shops). Others seem to say the artex bonding may not be enough to hold the tiles and I'll end up with the tiles and artex falling off the wall.

Can I tile over the artex? If not—what's the quickest and easiest way to get rid of it?

It's basically plaster, so unless it has a bunch of water damage or hollow spots, which you should easily hear by running your hand over the surface. I'd go with tiling over it, since the bond is just as good as plaster & people tile over that daily.

However, not knowing its porosity you should first apply a Thin-set Bonding Agent. The Artex or similar product has lasted this long in a wet environment, so I think it's proven itself extremely well. What you may not realize is that your plasterboard behind the Artex also quite likely contains asbestos. So, leave well enough alone & finally add a locking layer that doesn't have asbestos.


Old double glaze: steam doesn't go I'm renting, bedroom has some big old double glazed window. The steam showed in pictures below formed a few months ago. It's still there and apparently will never go! As a result the view is totally spoiled.

Is there anything I can do to remove this steam?

Nope. The seals in the window have failed, allowing moist air between the panes. This window has lost a lot of its insulating properties and the glazing needs to be replaced. Talk to the owner.


How should I attach a C wire on my chromalox boiler? I have a chromalox canada boiler model EDB-2. Recently I purchased a wireless honeywell transponder and thermostat, and am trying to install them. I currently have W and R wires but am missing a common ground C wire, and am unsure where to connect it.  I have 18/3 and 18/5 spare wires.

I've enclosed photos of the inside of the boiler.  The LV terminals are numbered T1, T2 and 1-5.

An HVAC consultant was able to supply power to the honeywell transponder.  Unfortunately when we attempted to use the thermostat, the transponder lost power.  The HVAC consultant felt that the boiler could not supply sufficient power.

So how can I connect the transponder to the boiler?

Click for larger views

According to the wiring diagram, the transformer should be installed between the T1 and T2 terminals. Though you have not shown the wiring in any of the photos, so it's difficult to give a better description than that.

However, since the transformer is only rated at 40 VA (volt-ampere), the maximum current on the secondary side of the transformer would only be 1.66666667 amperes.

40 VA / 24V = 1.66666666666667 amperes

In most cases the only things on the secondary side of the transformer are switches and relays, so this usually is sufficient. When you go installing thermostats that draw more current than that, you start running into problems.

If you want to install a thermostat that requires constant power, you may have to upgrade the transformer and any fuses that protect it.


wires disconnected in back of dryer I have an Indesit dryer. I pulled it from wall whilst still plugged in and the wires inside have come loose. I'm not sure which wire connects where.

It is a yellow box labelled d.e.m f3cc73002v5 inside dryer and there are 3 wires loose: blue, brown, and green/yellow. How should I reconnect them?

a yellow box called d.e.m f3cc73002v5

That would be an interference suppressor. It has a useful circuit diagram on it which shows how it should be connected. It also shows what it contains (three capacitors and a bleed resistor)

Some images from eBay:

L is the live wire in brown insulation
N is the neutral wire in blue insulation
The terminals at the top of the picture are for the earth wire in green/yellow striped insulation.

Note that the middle brown wire has a plastic insulating shroud to keep it apart from the blue wire. That protection is important.

However if all these have been ripped out by force there may be damage that needs repair.

All the connectors on this device are male spade connectors. The wires that connect to them should have female spade connectors crimped onto them. If they have been pulled forcefully off, they are likely to be damaged - check that there are no broken strands.

A damaged wire or connection could start a fire.

A loose wire, could blow a fuse or trip a breaker or electrocute anyone touching the dryer.

The safest thing to do is to get a service engineer to check and fix it.


Disconnecting a frozen water hose from a spigot! How would I disconnect a water hose after it has been frozen from the spigot without stripping either connections?

Fill a bucket or pitcher with hot tap water and pour it slowly over the connection. It should come apart almost immediately, but you'll probably need to repeat the process to completely thaw the spigot. Run some water through it to be sure, then close it and let it drain properly.


Inspection of flue from fireplace Is it possible to inspect a chimney flue from the fireplace to determine whether it needs cleaning? Maybe with a flexible shaft camera? What is the procedure?

Of course if you can get a camera up (or down) the flue then you might be able to see excessive build up of carbon (etc.) deposits. However, it will be as black as can be up there and the small light on most USB type endoscopes might not be bright enough to really make an accurate assessment.

Generally, if you're thinking the chimney might need cleaning, it needs cleaning! Chimneys are usually cleaned on rotation by time, i.e. once per year. If you're a 24/7 wood burner through 5 month long winters, then twice a year might be needed.

If you're an occasional fire burner, the flue still needs regular cleaning, because occasional fires don't get the flue hot enough to burn off small deposits. In fact, a little used chimney can be more of a problem than one which is screaming hot every day.


Bad drywall job or water damage? My wife and I just moved into a “new construction” house in Philadelphia. A few weeks ago I noticed a hairline crack on the kitchen ceiling. A few days later when working from home I saw the spot in a different light and noticed how raised the area is around it. What I want to know is if it’s water damage or just a crappy drywall job by the builder. There are other raised portions in the vicinity, but this is definitely the worst/most noticeable. It’s not soft, and the crack doesn’t seem to have gotten any worse after rain/snow the past few weeks, there’s also no discoloration.

I’ve included pictures of the spot at two different lighting situations

Appears to be a very substandard mud (drywall compound, thus, drywall joint) job, probably put on without waiting for each layer to cure, possibly also poorly reenforced, thus the cracks. The "Visible hump" is from lack of skill or care in properly feathering the joint.

Question will be whether this is the best the builder can manage, so having them do it over is pointless (as that's certainly sub-par for new construction) or whether you say the heck with them and fix it right either yourself, or by hiring someone actually competent. You might also want to take a harsh, glaring light to other drywall surfaces in the home to see if this is really the only bad spot.


Why do gas water heater exhausts have an air gap before the chimney? Every conventional (i.e., non-direct-vent) gas water heater I have seen has a roughly 1" vertical gap between its exhaust port and the exhaust vent (or "chimney"). See photo below. What function does that gap serve?

How does the gap not pose a danger? I assume that we never want combustion byproducts potentially venting into indoor spaces. But if the chimney were to become blocked, or during any air pressure imbalance between the exterior and interior, this gap seems guaranteed to vent CO2 into the living space. (And if the burner is not functioning properly, the exhaust could include carbon monoxide.)

The actual amount of combustion air - i.e., air flowing past the burner to provide oxygen and leave with less oxygen but more CO2 and possibly other combustion byproducts - is very little. The gap allows additional air to flow in and the combined air, if the ductwork is designed and installed properly, flows through the ductwork and out of the house.
If you did not have the gap, the amount of air naturally flowing through would often be too little to flow at a decent speed and would instead be more likely to sit in the ductwork. Hard to explain, but it just wouldn't work right.
A few additional points:

CO2 is not the biggest enemy - CO (Carbon Monoxide) is.
Yes, if you have too much CO2 you will have problems (think Apollo 13). But any house, even without any combustion equipment, needs to get makeup air with more oxygen to offset CO2 produced by people. But CO is incredibly dangerous and even low levels can cause a problem. CO is primarily produced by incomplete combustion which can happen easily in any combustion equipment if air flow is too low or there are impurities in the fuel or if a burner is clogged or many other problems. Therefore, you should have CO detectors near any area with combustion equipment.

Temperature of the output is actually a different problem than it used to be.
It used to be that furnaces and hot water heaters were relatively inefficient and the exhaust would be hot and you would want to make sure it all got out so you wouldn't burn your house down. But since it was hot, and hot air rises, that was easy to do.

Now furnaces and hot water heaters are so efficient that there is a different problem - the exhaust air, which you still want to get rid of because of CO2 and other potential problems, is too cold! So it doesn't rise as well on its own. That places a lot more rules on how to vent the exhaust, to the extent that where in the good 'ol days you would replace a furnace or hot water heater and reuse almost all the exhaust ductwork, now there is often a lot of work involved. But I digress.


What size plate for 2 1-gang boxes side by side Whoever put the electrical boxes in our kitchen before we moved in put two separate 1-gang boxes side by side (an outlet and a toggle) instead of just using a 2-gang box. The plates covering them were two single plates that had the edges cut off so they could butt up against each other.

I would like to replace the plate, but a standard plate won't fit. The outlet and toggle are about 1/2" too far apart for a standard plate to fit. Is there a specific plate made for this kind of configuration or will I have to just install a new 2-gang box and patch around it? If there is a larger plate, what should I be looking for?

Short answer: No

Whoever installed the boxes didn't learn how to do electrical work properly. So consequently, you have two single plates that have been trimmed.

If you were to find a plate like this it would be a custom item and may cost more than it is worth.

Either you will have to keep the trimmed plates, or you will have to replace the two single gang boxes with a 2-gang box.

Good luck!


How should I reconnect this switch? I suppose it's a three-way. The red light it's the only hot wire. It was like that when I came to the house. But the wire on top of the red it's going to other room switch and light. The one next to it. It's going to the room light. And the one under it's going to the other switch same room. I don't know where the other one is going.

It's in a room with two entrances. One light. And no the other room switch and light are not working.

I found this too. But idk if it was from there.

This is my idea, but please post a picture of the other switch of that room.


When it's smokey out, why does more smoke get into the house in the mornings and evenings? We've had thick smoke outside our home for several days now due to the fires on the west coast. We're doing what we can to filter the inside air and keep excess outside air from coming in (covered fresh air intakes, the dryer vent, etc).
You usually can't smell any smoke indoors even though it smells awful outside all day. However, every morning and every evening the smoke smell comes in for a few hours. I'm curious what causes it.
My best guess is that the air pressure outside increases during those times and that causes the exchange of air to increase. But that's just a wild guess.
Can anyone shed on light on what's happening?

The most common issue when you have make up air on a hvac systems is when the kitchen exhaust or bathroom exhaust fans are turned on they usually push 80-1000 cuft and that air is sucked in vis the central heat or air ductwork. If an older home is is pulled in through all kinds of leaky air spaces.
The most noticed time when the bathrooms and kitchen exhaust fans are running pushing house air out and bringing fresh / Smokey air in.


Unusual wiring in ceiling box for installing light In each room of my new apartment, there are ceiling boxes under circular white plates where presumably you can install ceiling lights since there are none. When I take off the plate and pull out the wires, they don’t have the typical white, black, and ground wires. They have one “free”/one-ended wire and two wires that loop back up and are attached on both ends deeper inside the ceiling. In the picture, you can see one free wire and one loop.

There is also a smaller loop up inside the box.  Any thoughts? Not sure how to install the ceiling lights with the two loops and only one exposed end wire.

Do you have any wall switches that either don't seem to do anything or that control an outlet? If so, check with a non-contact tester to see if the switches have any effect on either or both of the wires. One possibility is that the "free" wire is a switched hot and the "loop" wire is neutral. If so, then you should be able to split the neutral (cut, wire nut the two ends + pigtail to lighting fixture) and use that together with the switched hot.

Thinking about this a bit more, a neutral passing through (but not split) is common in a switch box (where switches that don't need a neutral will have the wire present but not connected to anything, just passing through to the fixture) but I am not quite sure how/why that would be the case in a ceiling box like this. Each switched fixture should have a separate neutral going back to the main panel, together with the switched hot back to the switch and then with the hot back to the panel. So while I can see a way the neutral might loop through, I'm not sure it is correct - so you really need to determine if it is a neutral - and the correct neutral (though why there would be a different neutral in the same location is beyond me) - or not.

If you can't find a switch that has any effect on any of the wires in the ceiling box then forget about trying to do anything with it, as the wires are likely for something else - e.g., central smoke/fire alarm.

HOWEVER, before cutting any wires or installing anything:

Determine the active breaker for the circuit, shut it off and make sure there is no voltage on the wires
If you are renting, check your lease for what you can/cannot do and/or talk to your landlord. Even if you think it is just an improvement, there may be non-obvious reasons why this is not a good idea or simply not permitted. The landlord may (quite legitimately) only permit any wiring changes to be done by a licensed electrician. Or the landlord may not care at all as long as none of the other apartments are affected.


How do I remove a stair tread under linoleum without damaging the linoleum? I'm replacing some old 1970s railing in between my kitchen and family room (there's a step down into my family room.)  I ripped that out and exposed what looks like a stair tread that was ripped down and used for the step-down edge.  I pulled that out because it was beat up and we are changing stain colors.  In the pic you can see the "anatomy" of what I'm working with:

So the edge sits on the joist and the fascia board.  (It was glued/nailed to the joist.)

Now my problem is that I need to get the other section out.  It looks like the linoleum is sitting on top of it...so how can I get that out and not damage the linoleum?  Undercut it with my multitool saw?  Or is that a fool's mission and should I attempt something else?

You can try heating a section near the edge with a hair dryer to see if it softens the adhesive.If you are lucky only the edges were glued.Use a stiff joint knife to gently lift the edge.


How do I troubleshoot and repair clanging pipes? I recently noticed that toilet supply pipes have started to "clang" when the tank is done filling and the water shuts off.  It started when the kitchen sink (opposite side of home) spray hose started leaking and I replaced it.  It had been making a cavitating noise and was shuddering, but replacing the spray hose eliminated that.  I am thinking that there is air in the lines, since it is not as pronounced upstairs.  Is there a way to bleed it out, or is it a symptom of something else like water hammer?  House was built in '72.

"clang" when ... the water shuts off ... is it a symptom of ... water hammer?

Yes.

...

...

Arrestor


Back of stove looks burnt I just had to replace the bake element for my GE oven. While doing so I noticed the back of the oven looks like it is burnt. Is this ok?

It looks like the insulation is intact I have seen much worse. I would leave it as is even the ground. If you do need to change any of the spade / disconnect fittings make sure to get high temp ones, standard female connectors like mni10-250dfix  will not hold up well to the heat, with the thermal cycling they become loose and will burn the end off. I learned this years ago after repairing an oven and the new ends did not last long, I use high temp (900 deg) ends like FR9C-250.
What you have there looks ok to me and is quite normal at when element entrance area so I would say it is ok.


Connect light fixture to a junction box I have a junction box where wires from 3 electric cables are connected together:

Is there a way I can hook up a light fixture to this box? The fixture looks like this:

It looks like you plan on using the pull chain.  If that’s the case I think you need a black wire from the fixture to the black marette and a white wire from the fixture to the white marette. If there is a terminal on the fixture for ground you would join it to the other grounds as well which I think have their own marette if I’m looking at that picture correctly. There are several experienced people involved with this conversation who you should consult with first, but I believe it’s the easy answer.


Do I have to cover the entire floor while painting a ceiling, or can I simply cover the floor in the area I'm working? I've decided to paint my studio, which is a 770 sq rectangular space.

I'm going to need to paint the ceiling as well as the walls. I'm going to paint the ceiling first then the walls.  I'm going to use a roller for the majority of the work.

Do I need to cover the entire floor before I start painting the ceiling, or can I move the painters cloth as I paint?

I don't want to buy 770 sq feet of painters cloth.

As a general rule; remove from the area or cover, anything that you don't want to clean later and/or possibly ruin.

Any hardware store should have poly film in large rolls - big enough to cover that entire area for around $20.


Turning on Dishwasher With 4-Hour Delay During Extreme Cold Weather I have several rental properties in suburb of Dallas. As you know that these week we will be experiencing extreme cold weather down to single digit, which is very uncommon for Texas.
Aside from the regular preventive measures that I used to give to tenants, ie., wrapping up outdoor faucets, dripping kitchen faucets, turning on ice-maker, setting thermostat to at least 70F, keeping cabinet doors open, etc., I am also thinking of asking them to turn on dishwasher before they go to sleep, setting it to 4-hour-delay start. I hope this will induce more water flow during midnight.
Do you think that this is a good idea? Does this step pose unnecessary risk to the life of the appliance? Any input would be very much appreciated. Thank you.

Turning the dishwasher on it shouldn't make a difference as long as they leave their kitchen tap run a little stream of water.  This should keep the main service from freezing.  Inside the house as long as you have a heater (which you said setting the thermostat to 70F) which is what I keep my house around at all winter.  They will not freeze inside the house.
It has been -40 here for a couple weeks now.  As long as you have a slow stream of water the lines should not freeze.  I do live in Canada and most of our water and services lines are 8 feet or deeper outside however.  I cannot attest to how or where your water and sewer services are ran inside or outside of your home and how much insulation is in your houses.
We have had to run garden hoses across lawns in the middle of winter to supply houses with water when their main services get frozen.  As long as the water flows it should not freeze.  DO NOT turn it off however.
Depending on the depth of your sewer lines and where they run you could possibly freeze them up.  (Like I said ours are usually deep in the ground when they leave the basement of the house).  A larger stream of water would prevent this but would use more water.


Yard Drainage issues We have clay soil so we had our landscaper/yard maintenance person come out to see what could be done for our drainage issues...there were many low spots in the yard & even when he stepped on them, he could feel the sogginess.

What he finally suggested might fix the problem is to just dig up our existing yard totally (backyard)...regrade it, then put down a layer of gravel/sand, put about 3 inches of topsoil on that, then put new grass seed in...He gave us an estimate of around $3750 to do this. But one of the issues I think we might have is that our gutters in the back come down & go into the concrete which is away from the house but could that be causing our soggy yard?

Where is that water going & how could that be tested to see? We want to the most cost effective thing we can do but still solve the problem...what should we be looking at and how do we know what to do?

Seems a little excessive to dig up the whole yard and not just add dirt.  But to find out where the gutters drain just add some food coloring into the gutter drain and see where it pops up.  It should come out a white 4 inch pipe at the curb but could be coming out a overgrown yard popup.  FYI it is illegal to drain rain runoff into a sewer line if you happen to not be able to locate the outflow someone may have done a no no.


Should frameless glass shower door hinges be screwed into the wall at an angle? I recently had shower glass & door installed - but the shower door hinges have their screws (ones that go into the tile wall) are screwed in at an angle, so they do not sit flush against the hinge.

All the screws are this way except the center one, I am wondering if this is normal?
I asked the guy who installed it, he said it is purposefully done that way so that it would be able to withstand the weight of the glass door.
Some details of the project:

This is a torn down to the studs kind of project
There are double studs behind the tile where the hinges are
The door is a 90 degree door

Any of you know if this is normal?

Any of you know if this is normal?

I would say not normal.
Looking closely at the photos i would say that if the manufacturer had wanted the screws to be at an angle then they would have set the countersinks in the brackets at that specified angle so the heads did not stick out proud of the bracket, They did not. The countersinks are straight so therefore one can assume that the screws SHOULD go in straight.
I would surmise that  the installer is feeding you a line to cover his mistake.


390 MHz Garage Door Opener and Raspberry Pi I have a lovely Genie garage door opener (I couldn't find a model number but it looks like this) that I've been wanting to upgrade for a while. I'd like to open it with an RF transmitter attached to a Raspberry Pi, as I'm uncomfortable wiring the Pi directly into the opener as some tutorials suggest.

I have been using a Genie GT90-1 remote to open the garage for years, and it seems as though it should be simple to use LIRC with an RF transceiver on the right frequency. This is where I've run into trouble, because while the opener and remote appear to operate on the 390 MHz frequency (reference one and two) I am having trouble finding any sort of 390 MHz transmitter/receiver that will connect properly to the Pi, most devices operating at 390 MHz appear to be Genie replacement remotes.

Is there any way I can make this project work, or is it DOA? The main obstacle seems to be finding a transmitter and receiver. Can I use something of lower/higher frequency, or some other alternative?

Thanks

You're making this more difficult than it needs to be. Use a relay connected to the R pi. If you want it wireless, then have the relay switch the button on the remote. If you want it wired, connect the relay directly to the garage door opener to its terminals to open/close it.


Want to run a new Electrical cable to new shed On our property we have a older shed (10 x 10) connected to the main panel by a 15 AMP breaker( the direct burial wire is 14/2).
I've  extended that shed and want to add more outlets and overhead lights.I'm want to upgrade that  breaker from a 15 to a 20 AMP, then use 12/2 romex inside the shed and 12/2 underground..
Do i need to remove the older 14/2 direct burial wire completely  or can it just be disconnected?
Also ,am i correct in thinking i can old run one connection to the shed, as well as the older wiring in the shed which is 14 /2 needs to be  changed out for the newer 12/2, due to the  higher breaker?

Can you abandon the old wire in place? Sure. Well, technically I think I recall reading something in NEC about removing permanently-abandoned wiring where feasible -- let's just say it's infeasible to remove that direct-bury cable and move on.
Yes, if you up-size to a 20 A breaker you'll have to replace the 14 gauge wiring in the shed with 12 gauge.
So far as circuits and wiring from the house to the shed goes you have options. A detached building is allowed to have a single branch circuit or a feeder circuit. Choosing the feeder option entails installing a subpanel in the shed and a grounding electrode system too (it's not terrible, just a little more work and cost than you had in mind).
"A single branch circuit" actually means more than a person would expect. If you wire that as a "multi-wire branch circuit" (MWBC) then you can have two 20A, 120 volt lines going out there while still calling it one circuit.
There is another trick for gaining an extra circuit: Add some kind of outdoor lighting on that shed. You can have a switch in the house that controls the power to that lighting circuit. You can also have a switch in the shed that controls the light. And if there are a few outlets on the circuit too, that's ok.. To complete the idea, just leave the switch in the house turned on all the time so that the outlets are always live and ready for use.
The new wiring to the shed needs to be UF-type cable which can be direct-buried or pulled (wrestled) through a grossly-oversized conduit, or else conduit with wet-rated loose conductors like THWN. Don't use NM ("Romex") cable for the underground portion. The conduit wiring method is unfamiliar to many people, but it's worth consideration.


How can i add a common "C" Wire to this old system? I have an oil HVAC that was put in back in 1996. I sadly do not know the model of the furnace and cannot dig out any paperwork on it.  Anyways, i want to go with some of the bells and whistles for a thermostat which needs the wire. I took off the cover and i did not see anything like the pictures i have found online nor could i find a transformer people spoke of. Maybe it is just that old?  Anyways, here are the pictures from the inside.

Bottom Panel http://imageshack.com/a/img538/4057/CZfxrA.jpg
Tstat wires http://imageshack.com/a/img661/1037/6qklHB.jpg
Wiring Diagram http://imageshack.com/a/img912/9646/DoAYY7.jpg

The transformer in this model is in the Oil Burner Primary Control. It does not look like there is a terminal to add a C wire. You're out of luck, bub.

From the manual: https://customer.honeywell.com/resources/techlit/TechLitDocuments/69-0000s/69-0617.pdf


How does my refrigerator water line connect to the valve? I was shipped a new Whirlpool refrigerator today. I had an existing 1/4 " copper tube that I used as a water supply line.

I cut the copper tube with a pipe cutter, and I slipped a compression nut and sleeve on the line. I slid the tube into the water inlet valve and tightened the compression nut.

After turning on the water (and verifying no leakage) I ran a gallon of water out the front dispenser. Suddenly, the fitting to which I attached the compression nut popped out of the valve and sprayed water all over. Apparently, there is nothing to hold this fitting in there. Am I doing something wrong, or is the valve defective?

The compression nut does not leak at all, and the water flows smoothly out of the fitting when it's removed as in the second picture.

This is the view inside the valve where the fitting plugs in. You can see the screen in there that stops debris. I don't see anything covering it.

Update: As you can see in the second picture, there is a lip that something in the green valve is supposed to grab. I can see two metal teeth inside the green valve that probably retract to grab the lip. Unfortunately, I don't see any way of making them retract. The blue cover on the front is like a public restroom screw: it's slotted such that it can be screwed on but not off.

Sorry to have wasted people's time, but I did learn a lot. The technician came, and the answer was that the valve was defective. The inner parts should have been clamped tightly around the lip during the manufacturing process.


How can I seal the large gap around my fireplace in a way that is safe and prevents air inflows? I've got a spot by a fireplace that lets cold air in. Unfortunately its right where the metal of the fireplace meets the wooden framing/molding of the fireplace on the inside. This seems like something I should be able to take care of. Its a rather sizable gap (maybe 3/4 of an inch). I didn't think I could caulk such a large gap. I wanted to use some kind of spray insulation such as "Great Stuff", but the label indicates that its flamable (not to mention highly toxic and needs to be covered).

What should I do to cover this gap and prevent air flow in a way that's safe and effective?

With regards to sealing outside

Unfortunately I can't seal the outside without great expense. My home energy auditor has said that its likely that the area surrounding the fireplace is not insulated. He has told me that it would be expensive to gain access to the gap between each stud and blow in insulation.

He suggested sealing the crack on the inside as the most cost effective way to improve the comfort in this room. When he came and used his IR camera, the spot on the floor next to this gap was in the 30's in temperature.

There's a gap between black slate(?) of fireplace and white wooden fireplace frame.

You can buy concrete in a caulk tube. I actually just finished doing this same thing to my fireplace that I remodeled, here's the product I used for the smaller cracks that I wasn't able to do with my bulk batch of concrete:

http://www.homedepot.com/h_d1/N-5yc1v/R-100357212/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

After seeing the photo of the gap in question a high heat silicon sealant would give a better matching finish:

http://www.amazon.com/Meeco-High-Temperature-Silicone-Sealant/dp/B002CTRWRQ/ref=pd_sim_dbs_indust_2


How can I treat or replace steel bolts in aluminum nuts to avoid corrosion? I have a structure originally built from aluminum extrusion with channels using aluminum T-nuts and steel bolts. Over the years, the steel bolts have rusted, making them prone to stripping at the head and getting stuck in the nut. I'm going to replace a lot of the bolts to get rid of the rust. Worst case, I replace them with bare steel again, and accept that they will rust again over the next decade or two. I would prefer to avoid that. Can I grease the threads or cover the bolt head with plastic or wax or something like that? Is there a cheaper material than titanium that I could upgrade the bolts to? Are there other solutions I should be considering?

PS: The solution needs to be vibration-resistant.

You could try using stainless steel bolts, dip in an anti-seizing compound like "Coppaslip". Under the head use locking washer, a good option is the "Nord-Lock" it is a 2 piece device, 2 washers that have serrated edge on one side and a series of wedges on the opposite side. The serrated edges grip the bolt head and the structure, the wedge faces face each other. They work by tightening the bolt and the wedges lock into each other, to release you first tighten slightly then quickly release. They are reusable and anti vibration, I used these often when I worked in the mines. Try this site for information; http://www.nord-lock.com/nord-lock/wedge-locking/washers/introduction/


How to fix drainage from gutters? I have two drains on the side of my house that have been filled in and no longer properly drain. I know they dont go anywhere because I just finished trying to unclog them with a rented drainage snake that I rented from home depot (and my neighbour actually told me the same thing!).

So, i'm wondering the best way to drain my gutters now. Should I:

a) break up the concrete that's on the sidewalk (side of the house) and re-do a french drain system or PVC?

b) Plug in the drain holes with concrete and angle them away from the house, to the other side of the sidewalk. Then, dig a trench from the back of the house to the front and install a french drain system.

c) something else.

A little history...

This was originally a carport that was closed in to make an extra bedroom. They built it with 2x4's running on the flat, and it had no insulation, and the siding went right down to the ground. When we took possession of the house we knew the siding had to be done, but not the entire room inside! What we found was rotten 2x4's, and a moldy carpet. We ripped it all up, re-built that wall and the siding (as you can see form the picture).

For the bottom of the wall, since we weren't ready to dig up the foundation and re-pour a 6" border, we put down 4x4's, peal-on-stick and we flashed it. Then, added roofing tar in between the layers and on the outside.

If I understand your issue correctly, what you're calling a french drain may actually more properly be called a drywell. A french drain pulls in groundwater and moves it somewhere else, while a drywell is a place to get rid of water underground. I think what you're talking about is something to pipe your downspouts into, and therefore I'd call it a drywell.

That said, one can construct a drywell in a similar manner to a french drain, by digging a trench and filling it with gravel and a perforated drain pipe.

The key difference to understand, however, is that if what you really want is a drywell to get rid of water, it may need to be bigger than you think. The rainwater doesn't immediately disappear into the ground surrounding your drywell, you need to provide some storage space so that you can hold the water while it can slowly leeches into the ground.

You may want to quickly estimate how much water you need to deal with. Estimate the square footage of roof drained by these downspouts, and then multiply by a rainfall amount (some sources say look up a 5-year 24 hr rainfall amount for your area, other sources say simply use 1"), to get an estimate of the volume of water that could be flowing out of these downspouts.  It adds up quickly!

If you simply dig a hole and fill it with crushed stone, you may need a big old hole, as crushed stone can have a void space of around 40%, so you'd need a hole 2.5 times bigger than your estimated roof runoff.

Therefore, you may want to consider an underground structure for your drywell, rather than simply filling a hole or trench with gravel.

One such product is made by NDS, called the Flo-well. It's a nice compact solution that can sometimes provide a good match for an individual downspout. You can stack them or daisy-chain them if you need more volume. Dig a hole, place the well, and backfill with gravel then topsoil. Simply plumb your downspouts into the drywell with PVC. The flo-well provides open space to hold lots of water, and has holes in its sides to allow the water out into the surrounding gravel and soil.

Or you could go with something even bigger if required, like some of the giant structures from Cultec that can hold up to 1200 Gal each, probably overkill for your application. These are like underground archways with open bottoms for the water to leech out of. Again, you'd dig a hole, lay a bed of gravel, place the chamber, and backfill with gravel then topsoil.

I have no affiliation with either of these suppliers, but have done some homework on this product space as I have a drainage issue of my own that needs solving on a tight, urban lot.

NOTE: If you are extra lucky and your property has some grade to it in just the right spot, it may be possible to simply run a pipe underground from the downspouts away from the house and have it come out the side of a hill to a place that you don't mind being flooded with rainwater. This is way simpler than a drywell. Just make sure to maintain positive drainage all along the pipe run (1/8" per foot or so).

image from www.askthebuilder.com


Do wall-mounted door stoppers with embedded springs provide any advantages over versions without a spring inside them? When taking a look at the various different types of available wall-mounted door stoppers, I've noticed two main types - ones that are simply mounted to a small hole that had to be drilled, and another similar option - the difference that this second version appears to have a spring inside it. Would there be any particular advantages of mounting a springy type - would the spring in the stopper provide more protection against the stopper itself if a door was hit hard into it?

The difference I have noticed is the spring models are less likely to be pulled from the wall if they are hit by a stray ankle or vacuum cleaner. They will just deflect out of the way and return to the normal position. A disadvantage is some cats find it makes a great toy and will strum the spring for hours.


What happens when you test a smoke detector? When you press the test button on a smoke detector it obviously beeps, but I'm assuming it doesn't just test the speaker. So, how does the test work? I can't see a practical way to release smoke within the alarm itself, so does it use some other measure in order to break the flow of radiation?

Ionization smoke detectors use a radioisotope to generate a very small electrical current, which when interrupted causes an alarm to sound.   These types of alarms use a metal–oxide–semiconductor field-effect transistor (MOSFET) to prevent the alarm from sounding, as long as the tiny current is flowing from the detector.

A simple dumbed down version of the circuit, might look something like this.

Notice the 9V battery is connected to the Source contact of the MOSFET, the detector is connected to the Gate, and the Alarm is connected to the Drain.  This means that as long as there is a current on the gate, current will not flow from the source to the drain.  If something (smoke) interrupts the current flow to the gate, current will flow from the source to the drain and the alarm will sound.

If you add a normally closed switch to the circuit, like so.

Opening the switch will prevent current from flowing to the gate, simulating a loss of current flow from the detector. Which in turn, will cause the alarm to trigger.

So when you press the test button on an ionization type smoke detector, you're not actually testing the circuits ability to detect smoke. Rather, you're testing the circuits ability to react to a loss of current flow to the gate contact of the MOSFET. You're also making sure the battery is not dead, and has enough juice left to sound the alarm if need be.


What size wire will I need to feed a 3/4 hp pump? I have a 230 v pump that will be 210 ft in the well and will be 820 ft from the house with a total of 1030 ft the pump is a 3/4 hp Gould pump What size wire will I need?

For a Goulds (CentriPro motor), 2-wire 3/4 HP submersible (5 FLA, 6.2 SFA) 8 AWG copper is recommended for up to 1420 feet (5% drop) by CentriPro. The chart is somewhat vague as to whether that's one way or round trip length; I'm sure you could call and ask, but 6GA is good for 2210, so 4Ga is clearly not required on that variant. Of course, I don't know that this motor is the one you have since you have not revealed your specific pump model.

Three wire motors require an additional wire, of course. Also an above-ground Start/run control-box. They also have higher amperage loads for the same power (6.6 FLA, 7.8 SFA). 8 Ga copper will only get you 1129 feet.

If you have not yet purchased the pump, I'd strongly suggest the 2-wire version.


Condensation forming on garage roof despite insulation I have a condensation problem on the inside of my garage roof. I noticed it in November, lots of condensation forming on the roof but only at the back half of the garage which is slowly being converted into a utility room. This hasn’t been a problem before, my only thought was maybe the tumble dryer was causing the problem as it is also located in the same area. I decided to buy some foam insulation at 75mm thickness as the void between the wooden beams and the garage roof was roughly 150mm therefore I knew using 75mm would leave another 75mm air gap between the insulation and roof. I did the job using foil tape to seal all joints and even spray foam in small gaps but make everything as air tight as possible.
Today I decided to check the roof, running along side the garage is a full length passage way that has the same flat roof as the garage and I didn’t insulate this part as I wanted to inspect the garage roof over the utility room for more condensation. To my horror it is probably worse now. Water drops are dropping onto the foil back foam insulation with more condensation forming on the roof. It’s also so cold in there at the moment that some of the water is turning to ice. I can only assume one of two things is the reason. 1.) I need to also insulate the passage way too or 2.) some how the tumble dryer is still managing to penetrate through the insulation and create condensation. I’m slightly at a loss here. I’m not a great DIYer but will do what I can to sort this issue if anyone has any ideas?

The principle at work here is basically this: condensation, or dew, forms when humid air is exposed to a cold surface. More specifically, it forms on a surface when the temperature of the surface is below the dew point of the air. It's the same thing that happens when droplets form on the outside of a glass holding an ice-cold beverage.
One way to prevent the condensation forming is to keep the air-exposed surface warmer. Obviously the exterior of the roof is simply going to get cold in winter; there's nothing to do about that. What one can do, though, is apply vapor-impermeable insulation to the interior side of the roof deck and keep the interior space warm. "Vapor impermeable insulation" often translates to "closed-cell spray foam." With this foam applied the water vapor in the air can reach the foam's surface but can't permeate deeper into the roof assembly. The foam's surface is warmed above the dew point by heat from the room and condensation is prevented.
The other (and more common) way to prevent condensation is to control the dew point. This is done by controlling the relative humidity, which in turn means controlling sources of water vapor and venting whatever vapor is created. This is why we often use layers in exterior walls and roofs:

interior wall finish
vapor barrier
insulation
exterior wall substrate
exterior wall cladding

The vapor barrier prevents (slows) diffusion of water vapor into the insulation. If it were absent then vapor would condense in the insulation -- or, if the insulation were absent too, then the vapor would condense on the wall substrate.
The foil facing on your insulation should be a good vapor barrier especially because you've taped the joints. Somehow, though, vapor is getting around the barrier. Maybe you can improve this.
When you've done all you can to control vapor sources and to establish a vapor barrier, then next defense is to ventilate the roof/attic space to exhaust whatever vapor gets in there.


Dangers of bootleg ground and GFCI? Bootleg ground means a scenario equivalent to (deliberately) bridging the ground wire and the neutral wire.

How it was physically done (e.g. bridged screws on a receptacle, deliberately bridged wires in the wall without a junction box, or otherwise) is hard to find in a home one moves into. This DIY.SE post shows the dangers of bootleg ground: one fault can energize everything, including metal chassis. Does replacing the example’s regular receptacle with a GFCI receptacle alleviate the problem at all? This 05/30/2017, 09:39 Wikipedia entry implies it won’t, but doesn’t cite a source, so I’m not sure about its correctness.

This other DIY.SE post implies any GFCI with bootleg ground can’t be tripped by external testers but can be tripped by its own test button, but given that Wikipedia entry, I’m not sure which one is correct. If Wikipedia is correct, does that mean such GFCI can’t be tripped with either method?

I tested 2 GFCI receptacles and they’re on different circuits. I used the Amprobe INSP-3 wiring inspector circuit tester. One GFCI can be tripped by both its own test button and my circuit tester. The other can’t be tripped by either way. I measured .45 ohm ground impedance on the latter. Does that mean bootleg ground?
 This video says properly wired receptacles should have 1 ohm impedance. The video’s bootleg ground receptacle tested with .03 ohms impedance using the same tester. Amprobe throws a warning if it’s ≤.04 ohms.

How can I make such GFCI receptacle extend protection downstream and function properly without adversely affecting any other receptacles (on the same or different circuits), breakers, or main panel?

Is it as simple as disconnecting the GFCI's ground wire on the line side? Must I also disconnect the ground wire on the load side? Could this adversely affect bootleg-ground upstream receptacles?

Must I also disconnect all ground wires on the line and load sides of all downstream receptacles, too? Is it safe to leave said disconnected wires in the box or wall? Or, is the only solution to tear the walls apart?

Which does any GFCI disconnect upon tripping: ground, line hot, line neutral, load hot, load neutral? If tripping doesn’t disconnect ground, then wouldn’t a disconnected upstream neutral be dangerous if there's a load elsewhere on the circuit?

I’m in a guest house that has a (sub?)panel that likely sources from the old main house. The main house likely has bootleg ground receptacles and I don’t know what’s inside its panel other than it doesn’t have GFCI breakers.

The .45 ohms ground impedance was measured in the main house’s GFCI receptacle. The guest house has all non-GFCI breakers & non-GFCI receptacles, the latter of which measures .04-.07 ohms ground impedance. Are these bootleg ground? I see 3-conductor Romex when opening some of guest house's outlet covers but can’t search everything. I don’t know if guest house’s Romex is correctly wired or if it matters given main house’s condition.

Would installing GFCI breakers in the guest panel be safe or can the main house’s condition energize the guest panel?

If it’s safe, would these breakers protect everything downstream if some or all downstream receptacles or unmarked junctions have bootleg ground? Must I disconnect all downstream ground?

For the guest house, I have the same question if opting for a GFCI receptacle instead. What are the dangers of replacing a regular receptacle (that has 3-conductor Romex which might be compromised upstream with bootleg ground) with a GFCI receptacle in the middle of a circuit and connecting the GFCI receptacle’s ground?

If you don't trust a ground, don't connect to it - use GFCI instead.

If a GFCI won't trip with its own internal test button, it is duff.  Into the trash it goes.

Here is how GFCIs and ground wires are supposed to relate to each other -- or to be more precise, how they are not.

To the left you see unprotected hot and neutral coming in, out the right you see protected hot and neutral, which I've recolored.  Ground sails right by unconnected (normally).  Obviously, if your ground is corrupt/defective, this is bad news indeed.

"Wait, all the GFCI's I've ever seen have a ground screw."  No.  That thing you call a GFCI is actually a GFCI+receptacle combination device.  It provides a GFCI module, and also two sockets (wired past the GFCI). The GFCI can't use ground. Look at a GFCI breaker, it doesn't even have access to ground. The ground is for the sockets.  This means effectively, that ground screw is on the "protected" side of the GFCI.

So if the ground is bad, where should you cut the ground?  Before it reaches any protected loads, and remember, the ground screw on a GFCI+receptacle combo serves the protected loads.

Should you do anything creative like tie the protected-side ground into protected-side neutral? No No No! This post of mine explains how that utterly defeats the GFCI protection.  Wrap the ground wires with tape so they can't touch, and don't use them.

Detecting tied ground-neutral

If your panel is set up this way, the single easiest way to test your neutral-ground isolation is to disconnect your neutral-ground bond in your main service panel.  Now the only thing connecting neutral and ground is that long path of dirt between your grounding electrode system and the pole transformer's. If you also unhook your grounding electrode, your house's internal grounds should be fully isolated from neutral, and should megger out at a couple megaohms.  (Don't megger things in residences though, it could fry electronics).

Or test circuit by circuit.  It's a simple thing, on any given circuit there should be 0.000 amps of current flow on the ground wire. Nothing is supposed to use ground but test equipment.  Now, if neutral and ground are tied together, current follows all paths in proportion to their conductance (1/resistance) so a significant fraction of current will take ground instead of neutral (assuming there is a load).   Obviously a GFCI will detect the shortfall, but a clamp meter will detect the ground current directly.

I don't agree with that video's claim of nearly 1 ohm between neutral and ground. Copper wires have much better conductivity than that unless he has many hundreds of feet of wire between his lab and his main panel. There may be something peculiar going on in his test lab, or he is misunderstanding or misusing the equipment. You shouldn't have 1 ohm neutral-ground, that would limit dead-short current to 120A, which would not flow enough current to safely magnetic-trip a breaker.

In any case, a clamp ammeter around the N-G bond (or a circuit's ground wire) would soon show if any AC current was flowing.


Are Quick Connect Shark Bite Connectors Safe to use with a Boiler? I have a section of piping I want to clean up, and while out to buy some supplies to practice my pipe sweating I found out about Quick Connect Shark Bite connectors. I was told they work for both residential water and boiler applications but I wanted to know of examples or things to look out for.

My boiler operates between 120 °F and 160 °F @ 12 psi to 25 psi with the high temp cutoff at 190 °F.

In the winters it's become necessary to run the heat 24/7 for about a week at a time, so softening of the plastic seal because of heat is something I am concerned with.

SharkBite fittings are certified to 200 PSI and 200°F (93°C).

Lots more info available on the official shark bite website.

Here is a link   to FAQ on the site where I found this answer.


No loop to hang dish washer drain hose higher This is behind my dish washer and the drain hose has been like that for awhile (by laying flat on the ground):

I believe it should be hang up to make a loop on top, right? But there is no where to hang it behind the dish washer.

Under the sink, it is a long hose. I am wondering if I should mount it on the wall of the sink cabinet?

Please advise.

I think you have the right idea. It can't go behind the dishwasher - there is normally no space at all between the dishwasher and the wall.

Typically a dishwasher will be mounted next to a sink. The hose should be long enough that you can loop it up on the side or behind the sink so that it goes up to the bottom of the counter, or at least a few inches higher than the sink drain.

If the hose won't stay up by itself, screw a piece of metal or plastic strapping to the side or back of the sink cabinet near the top and loop it loosely around the hose to hold it up. Just don't loop it so tight that it crimps the hose.


Painting over cracks in ceiling Our kitchen ceiling has several cracks in the plaster. We need to repaint the ceilings and didn't know what our best option was for the cracks. We don't want to do some sort of plaster because we figure we won't be able to get the matching texture of the ceiling and it would be very obvious. We were thinking using good ceiling paint that the cracks would be concealed. Is this a correct assumption or no?

I encountered this in my first property, which due to the age of the building would have cracks in many walls and ceilings.

In my experience paint does not do the job.  Perhaps if you slapped a lot of thick, gloss on top of them you could "fill" them, but I don't believe standard interior matte paint will reduce visibility of the crack.

In an ideal world, you would tape over them and use some sort of jointing/finishing compound to cover the area approx 5cm either side of the crack along it's length.  A bit of sanding and paint and you're sorted.

However, with your ceiling this is either going to be impossible, or look very obvious after the fact.

Advice you don't want, but will definitely fix it: re-plaster the whole ceiling

Cheaper, but might not work: run some caulk (with the smallest nozzle possible) down the crack and smooth in with your finger.  Wipe away the excess and let it dry.  Paint over.  It may not be perfect, but it has the potential to work in the long-term as the caulking is more flexible and will allow for a little movement.


How much concrete is required to hold 125 lbs/sqft permanently? I have an garage with asphalt floor and concrete footings. I plan to put a 500 lb safe in the corner, partially on the footing. That's about 125 lbs per square foot including contents, permanently.

To make a level base, I plan to dig up that patch of asphalt and pour high strength concrete.

What depth and quality of gravel do I need under the concrete pad to safely hold this weight? What depth of concrete do I need?

Here are some additional details. The corner of the garage actually has a U shaped concrete footing with asphalt in the middle. The gap between the footings is too large for the safe. The portion of the footing holding up the garage wall has been repaired and is solid. The unused/bare footing and the asphalt is known to be weak due to insufficient base.

Base on your description:

Concrete strength does not appear to be an issue. With a minimal 2500 psi concrete the entire safe could bear on one square inch.
The size of the footing depends on the bearing capacity of the soil. Suppose the soil has a bearing capacity of 20 pounds per square foot. Then the foundation would need to be 25 square feet. Other soil bearing capacities would require larger or smaller minimum footings.
Placing a new foundation near an existing often has substantial engineering implications. The forces overlap on a portion of the soil because the bearing capacity of a soil is a function of it's ability to distribute loads. Consultation with a professional engineer may be in order.


What is the best way to repair MDF furniture? Our kitchen is made almost entirely from MDF.

We have 1 closet where the hinges have pulled out and several drawers where the screws have pulled out. The MDF around the screws has just been eroded so the screws no longer fix in.

What is the best way to fix these screws so they stay in?

For holes that are the right shape, but worn, add some wood glue, and screw it back in.
For a little extra friction, stick a little piece of one of those plastic coffee stirs in there too.

If chunks of mdf have broken off with your screw, you'll need to cut some more away,
and glue a replacement block in place.

It's important to use a clamp when gluing pieces together. Then lightly sand (just to rough the surface), clean, and prime, before repainting.


Will layered roofing paper help level a floor? We plan to have a contractor install new hardwood over existing heart pine that is not refinishable. An area of one room is unlevel in this 100+ year-old house. At least one flooring contractor suggested folding over and layering roofing paper in the low area, then adding luan over that, before installing the new hardwood. Is this a reasonable solution? We do not want to pull up the old floor and level it from underneath.

There is nothing wrong with using roofing paper or even shingles (my favorite) if there is a floor slight out of level.  Floor leveler is an option too but I usually use floor leveler for floating floors and shim traditional hardwood with shingles.

The reason for this is leveler sometimes has issues with staples or nails going through it.  I prefer shingles vs any other type of shim because shingles don't break, take nails well, and they don't need to be compressed.  There are limits to how much you can shim but that is true with a leveler too.  But innately there is nothing wrong with shimming flooring with roofing paper/shingles.

One thing I would add.  If you are redoing all the flooring, if you can have the joists checked out below it is a good time.  The flooring guys probably don't care about this - as the trades usually don't mix.  But the flooring might be able to be leveled with a set of jacks and the new floor could be installed without shims or leveler.


Unable to screw through plaster and lath wall I am trying screw in a 2 1/2" screw into a wall that I'm pretty sure is plaster and lath.  But when the screw is about 1 1/2" deep of drilling, it doesn't go in anymore no matter how much force I put in.  From a stud scanner, the area should be where a stud resides. I'm using a 20V DeWalt driver.

Has anyone seem such problem?

Best case is you've probably hit a concrete structural wall.  In that case use a hammer drill and cement screws or anchors if you really need more support than you get from the 1.5" in front of it.

Worst case is you're hitting a conduit or water pipe, in which case thank goodness you haven't managed to puncture it.

I'd look for a work box or some access where you might probe the wall to determine what's back there.  If it's the former case you'll see that.  If you don't see a cement backer then carefully drill probe holes around where you were trying to screw and see if you end up to one side of the thing you shouldn't be hitting.


Furnace entering lockout mode - air flow problem? I have a Nordyne KG7SA, about 2009 vintage, which has begun acting strangely. We started noticing that the thermostat would drop several degrees below the set temperature before engaging. More recently I started noticing it seemed to cycle very quickly several times in a row, then just quit. Then on Christmas Eve it stopped working altogether.

I was able to get it working again by turning it off and back on again, but it would only run for ten minutes or so before starting the short-cycle routing again, and shutting down.

After doing some Googling I came opon the thought that the filter might be too dense (it was one of those 3M "allergenic" filters). So I removed it and the furnace began working normally again.

Today (12/26) I picked up a new, lighter filter and the quick recycling started happening again after a few rounds of heating. I had the presense this time to observe the status code - alternating blinking red and green - which I'm led to believe indicate a one-hour lockout mode. This seems to be consistent with the delayed cycling we'd observed in the past. (Side note - why are these status code legends so hard to find online?)  When the filter is off and the unit is operating normally the status lights are solid red and green.

So in my most uneducated estimation it seems my furnace is having some sort of air flow issue.

One other point I should add - my dehumidifier filter is in dire need of replacement. It's a GeneralAir 1099LHS and I'm having a hard time finding new filters for it. Could this be contributing to the air flow issue I'm experiencing? If I set it to summer mode and bypass it (in the short term, anyway) might this alleviate the issue until I can find a replacement?

My main questions are, do I seem to be on the right track in my diagnosis? What would be some logical next steps to troubleshoot and isolate the issue? What might be some low-cost things to try in an attempt to solve the problem?

I'd have to say to get an HVAC technician in for a complete cleaning, overall inspection, adjustment and, of course, solving the problem...keep using the better filters, they're worth it to you and to the system.

Yes, it could very well be an air-flow problem and the filter removal may have partially addressed the problem. However, if you have cooling on top, then the filter removal, possibly, revealed the problem's deeper and you have a dirty A-coil. This, is what the air always blows through regardless of heating or cooling.

And yes, it could be your humidifier if a majority of air flows through it with your setup...uncommon for what I've seen. However, your blower fan or even burners could be clogged-up or you may have a circuit board, transformer, sequencer, limiter or even igniter that's failing.

Sorry, HVAC is just a bit too complicated anymore and even the codes thrown by them are commonly just a symptom and not the cause. If the unit's never been serviced since 2009, then it's definitely due and may have been wasting money for a couple of years.


Replacing pendant lights and have a question on all the ceiling box wires I'm trying to change our existing 2 pendant lights over our kitchen island to new ones we purchased. House was built in 2005 (modular home). After removing 1 of the existing pendant lights I panicked about why I have (out of the ceiling box) 3 white wires and only 2 black....I capped everything off with wire nuts...and STOPPED  :)
 Inside the ceiling box there were 2 black wires and 3 white wires that were connected with brass/copper color tube thing and squeezed together and then they had a clear big cap that looked like a wire nut. The 3 ground wires just have the copper/brass tube thing attaching the ends squeezed on. (see pic 1)

The old pendant light (see pic 2) had one yellow coated wire that was pulled apart into two wires, then one silver wire that was attached to the base of the pendant and 1 copper color wire that was I assume ground? Wiring was like this on the old pendant light to the ceiling box …They attached one of the yellow coated wires to the white (3) bundled wires of the ceiling box. They attached the other yellow coated wire to the black (2) bundled wires of the ceiling box. They attached the silver wire to the green ground screw of the plate.  They attached the copper wire to the 3 copper (ground) bundled wires inside the ceiling box inside the brass/copper color tube thing as described above.

I pulled off the tube connector thingy of the white and black bundles. I cut the copper skinny wire from the old light fixture from the copper (ground) bundle in the ceiling box. (you can see the tail end in pic 1 - the other end is still inside the tube connector on the bundle of the copper (3) wires inside the ceiling box).

Here's my questions:
1) why do I have 3 white and only 2 black wires in that ceiling box? Could the white extra be coming from the recessed lights elsewhere on the ceiling? Those lights are on a dimmer switch (which does NOT control the pendant lights)
2) Do I attach (from the new pendant light) black to the (2) black wires, white to the (3) white wires, and ground wire to that little piece of left over ground wire hanging from the ceiling .Or do I put the ground from the new light onto the green screw on the plate only?
3) I have orange, yellow and red wire nuts connectors (size in that order) - which ones to use for these large bundle connections since I don't have those brass tube connectors that you squeeze on?

The silver wire is also a ground.  Chains are not grounding paths so a pendant needs 2 grounds - one down the chain to the pendant, and the other for the box cover.

I suspect the manufacturer ran an extra run of 14/2 (12/2?) Romex from the switch to support a ceiling fan which you don't have (yet).  I bet the third black is folded up in the back of the box, but they tied this pair's white wire with the other white wires.  That's making my spider-sense tingle, but I can't say why.  Might make a good question.

Since the power is fed from the switch (no weird switch loops) you should be able to connect all blacks to each other, ditto the whites.  All grounds must  be connected together.  I don't see any obvious way that upper steel plate bonds to the maze of ground wires above it, and that makes me a bit nervous.  Is that a steel box above, and is the ground bundle bonded to it in some way?  I see a screw, but it's not green and may be a physical mounting.  Is the steel cover plate tightly screwed to the steel box?

As far as wire-nuts, each make of wire-nut is listed for certain combinations of wire.  For instance Ideal's 73B (orange), 74B (yellow) and 76B (red) are covered in a document titled  UL Listed wire combinations...    Generally I like to be in the middle of the working range for a wire-nut, so I'd go yellow for 3 wires, red for 4, and orange for something that seemed on the smallish range for yellow.


How Should I Fill In a Hole in Slab Around Floor Drain I think I have a good idea about how to go about this, but wanted to throw it out here to make sure I don't wander down the wrong path.  I recently installed a new floor drain.  I broke up the concrete in a circle around the old drain, maybe 14-18 inches in diameter.  Under 2-3 inches of concrete was gravel and a few more inches down was the clay dirt under the house.  Below is a picture generally representing this.  There was a 4" PVC pipe running up from the ground where the old drain was attached.  I cut off the old drain and solvent welded the new drain (also PVC) onto the end of the pipe.  Now I want to fill the hole back in and finish the concrete level with the new drain.

I have a pile of gravel, broken up concrete chunks and dirt which I excavated from the hole to access the pipe.  I could put some of this material back in, maybe fill in around it with sand, building up layers of that until I'm about where the concrete begins in the surrounding slab, and then fill that area in with concrete.  Does this sound about right?  Am I way off?

Also, I welcome any suggestions on what kind of concrete to use (or what to specifically avoid).  Once it's dry, I'll be grinding the surface of it (and the entire floor) in order to lay down a sealer or epoxy or something.

If the PVC drain indicates the age of the plumbing and the house, or at least when the slab was installed, there should be a layer of poly acting as a moisture barrier in between the concrete and gravel. Aside from that, all you need is to add the original gravel back into the hole and repair the vapor barrier and finish off the fill with a bag or two of concrete from any local building supply, big box or otherwise. A detail that would be good to do is be sure the hole cut inti the concrete floor is not all undercut. As in, the concrete should not be broken out so the hole is larger the bottom edge of concrete than the concrete at the floor level. A little undercutting is ok, but the concrete you add needs to lock in so it will not settle down away from the original concrete.


One dodgy lamp: Differential is triggered and several separate circuit breakers become differential-triggering. How is that even possible? I had a bit of a phenomenon on the neighbour's electrical circuit.
What was observed:

The differential had blown

What was tried:

I tried to to isolate the faulty circuit by trying to get the differential stay closed.
Trial and error resulted in several circuit breakers set to "open" until this was managed, with no obvious pattern. For example, the circuit breaker for the fridge and the circuit breaker for the oven both had to be "open". Closing them would trip the differential. Even then, the differential randomly tripped after maybe 5 minutes of stability.

What fixed it:

The neighbor remembered a dodgy lamp plugged in. It was indeed doddy, as the power supply was broken open with the transformer spool clearly visible and the grounding cable had broken loose.
After unplugging said lamp, all the ciruit breakers could be closed and the differential could be satisfactorily closed and stayed this way.
I'm not sure whether I "isolated" that lamp through opening one of the ciruit breakers earlier, but probably yes (judging from the inscriptions on the breakers at least).

Question:
How is it possible that a single device on the "power plug" circuit causes the circuit breaker of the "stove" or "fridge" circuit to become differential-triggering-when-closed?
I actually suspected a major problem with the cabling at first, like water intrusion or a rat having a final meal. I reckon one should have a professional take a good look at this phenomenon?

Perhaps a neutral-to-ground short in the lamp, which is not disconnected by opening its breaker, is creating a current path impacting other circuits.  I can't say exactly how as I don't know exactly how the multiple RCDs on a panel interact with one another through their common ground and neutral bus.  But it's the only possible explanation.  I'm guessing you are in a home with European-style RCD groups controlling everything in the house, is that right?


How do I remove concrete that has splattered on my brick pavers? We installed a brick patio, and splatter from wet-cutting the bricks ended up on the installed bricks.

How do I clean it?

Use a pressure washer with the widest angle nozzle held about 2 ft or more away from the pavers will take off the residue. Don't get too close or the intense water pressure will also take away the smooth finish of the pavers..


Mounting an outdoor ceiling fan in a pergola? I'm would like to mount an outdoor fan in a pergola in an attractive way.
In the first photo I like how the junction box (?) is hidden.

Everything I can think of doing is going to end up looking like the one in this second photo.

I am with you, the first one is much more attractive.
The jct box must be mounted on a cross member, 2x4?, and then they added boards with a hole for the jct box.
It would be just same as if it was in ceiling and drywall except the box would need to be set at the correct depth for the thickness of the wood.


Holes in brick mortar? There are a couple holes in my house's exterior brick mortar about 3/8" in diameter.  Is there any reason not to fill them in?  I only hesitate because my masonry knowledge is pretty much nil.  Both are beneath windows (one is far below, though), but I wonder if they could just be old anchor holes since one is below three anchors.
First hole:

Zoomed in:

Second hole (mind the photo bomb):

Holes near the bottom of the wall are "weep" holes that let any water that gets behind the bricks drain out.  These, however, are not weep holes and look like they were drilled to mount something to the wall.  Perhaps a hose rack or reel?
In any case, yes you can fill them in.  They are small enough that you could use some mortal-colored caulk.
By the way, you should probably address that crack also.


Can these walls support bookshelves? We are trying to add bookshelves onto our apartment wall; specifically, elfa system shelves (site is in Swedish, but I'm sure you can get the gist based on the photos). However, we are somewhat concerned as to whether or not the wall can support the shelves.
Our concern, however, is that the wall itself may not be ideal to mount into. It is built over the brick exterior of the building with approximately 5cm of empty space between the plaster wall and the brick. The drywall itself, unfortunately, does not run all the way to the ground: due to a water pipe that runs along the floor to a radiator, the plaster doesn't sit directly on the ground, nor on anything, really.

We have used a stud finder, but what it has found is... inconclusive. We could not really consistently find any indication of what the plaster is mounted on that we could use to also mount our shelves into, and so our only hope would be to mount the shelves directly into the drywall.
We are aiming to mount the rails with these kind of drywall anchors, but the concern of course is that I assume any description of how much weight they can support is predicated under the assumption that the drywall itself is well-supported. Unfortunately, we can't really tell if that is the case or not.
Our questions are the following:

Is possible and safe to mount bookshelves directly into the drywall?
If not directly, is there something we can do the help support the shelves?
More generally, how can we get a sense of how much weight can be safely supported?

We should not that this shelf would be above our living room couch, so since we don't relish the idea of always wearing safety gear while relaxing, we want to ensure that our shelves will be stable enough.

Not possible by just going into drywall.  The achors are not designed to bear that kind of load.  The reason this won't work is because of torque.  Drywall anchors are designed to support loads that are very near the wall (i.e. pulling, more or less, straight down along the wall).  Your shelf will probably have the load offset from the wall by a few inches, which will eventually pull the anchors out of the wall.  This is because of torque.   The farther you go from the wall the more torque you have.  While the shelf may hold for a while I would not trust it.
The torque on the anchors can be mitigated by putting in angle brackets.  These effectively redirect the load from the edge of the shelf back to the wall.  This is better, but I still wouldn't trust this shelf unless it is secured into something more than drywall.