I-joists on an old dimensional lumber floor I’m remodeling a room on my first floor and will need to move a HVAC duct, make it run across 4 joists of the second floor. Room is gutted, and I can see second floor has a 3/4" OSB subfloor on dimensional 2x10 joists, 16" OC, 13’ in span:

Ducting is 6" round so I cannot drill through the dimensional lumber I have in place without compromising it. But I could if I had i-joists (a 9-1/2" i-joist allows up to 7" roles per manufacturer). So I'm considering this:

Assuming this is my only option, but being happy to be proven wrong, my problem is: a 2x10 is actually 9-1/4" but the i-joist is 9-1/2", so I see two options to make up for the 1/4":

Align the top of the i-joist to the top of the current joists: that would bring my ceiling 1/4" lower only on those 4 joists so I'd need to shim every other joist to match. I'd also need to notch the beam and top plates so the i-joist can sit lower

Align the bottom of the i-joist to the bottom of the current joist: same issue, and even greater pain because it would mean ripping the subfloor upstair, shim the top of the other joists and re-install it

So #1 seems easier since ceiling is already gutted but I'd need to bring the whole first floor ceiling down.
Yet another option is go with #2 but route a 1/4" rabbet on the underside of the subfloor for the top of i-joist to tuck into. The subfloor is 3/4" which would leave 1/2" and I was planning on adding a 1/2" underlayment for hardwood floors on top of it anyway, so doesn't seem to me there would be a problem:

Looking for any ideas besides the ones mentioned here, or to be talked out of my hacky third option
Notes: Shaving 1/4 from i-joist flange is out of question, per manufacturer's manual. And I read i-joist manufactures make it a pain on purpose so builders are not mixing dimensional and engineered lumber due to differences on expansion rate, warping, etc. but that doesn't seem to be an issue on my case (I thought about sistering the current 2x10s with i-joist but after reading that I changed to replacing it altogether)

I think an I-joist is a good solution.
Your existing 2x10 floor joists have dried out over time and are stable enough to mix with I-joists.
However, I question the 7” allowable hole size. I’d double check with your I-joist manufacturer and follow their guidelines for size AND distance from bearing point.
There are many sizes and grades of I-joists, so be sure to coordinate all that with the manufacturer. I have no doubt the 9 1/2” I-joists will be strong enough for your 13’ span.
I’ll give you a third option: Option 3: Use the 9 1/2” I-joists at 12” on center. Align the lower chord with your existing 2x10’s (this allows you to use the existing bearing walls, beams, etc.) so no adjustment for replacing the ceiling. Then, use 1/2” plywood subfloor instead of replacing your 3/4” subfloor. (1/2” plywood on 12” centers is as “stiff” as 3/4” plywood on 16” on center.) You won’t notice the difference.
The underlayment can be reinstalled or the existing underlayment or it can be removed throughout the space and new installed for uniformity.

Split the duct into 4 3" pipes and put those through 4 3" holes in the existing joists.


Can I patch and tile over a phone jack? I am tiling a backsplash in the kitchen and there's an unsightly phone jack that I will never use. Is it advisable cut the wire, remove the box and patch over it? That's a stud behind the gap between the two electrical boxes.

Yes, if the wire is out of service, remove the plastic panel, secure the wire with insulation tape and put your tile over it.

"Out of service" not connected to the main telephone system!

If it connected, but you have other PSTN jacks in the house, cut the wire ONE by ONE with insulated wire cutters!. Then insulate each wire with tape and finally the entire wire.

You will also need to remove the socket on the right, and then replace it when you done tiling, as the mounts need to sit ONTOP of the tile, and the plastic cover will hide the mounts nice and flush.

You could also leave a nice message for somebody in the telephone box, when they take the tiles down in 25 years, that it was a telephone wire.. or where you buried your gold treasure. Heheheh

Bandage the insulated tips with duct tape if using electrical tape as heat over time will loosen the tape, and you don't want a short on your phone line. The bandaging might be overkill but it's safer.


Using Both Sonoff Wi-Fi Switch and Existing Wall Switch to Control Light EDIT: Oops, I meant to say hot/neutral for (+)/(-). I'm not completely educated in this as you can tell. ^_^;;

I live in the U.S. I'm attempting to figure out if it's possible to hook up a Sonoff Wi-Fi switch to my house's light fixture, let alone if it's possible to do it with the existing wall switch. I know there's Wi-Fi switches you can buy that only require you replace the existing light switch, but they're super expensive, and the Sonoff is only $4. So I want to get this to work so I can use my phone to turn the light on or off no matter where I am in the world. I also want to still use the existing wall switch to control the light. But I'm not sure it's possible since Sonoff outputs two wires whereas a regular light switch just cuts off the (+) wire to control the light.

Here is the current wiring setup of one of my ceiling lights and its wall switch:

The AC's (-) connects directly to the light's (-). Then the AC's (+) goes down to the wall switch (a switch leg wire, I'm told it's called), then back up again to the ceiling and into the light's (+). This way the switch turns on or off the (+) to activate the light.

My plan, if it will work, is to mount the Sonoff box above the light's junction box in the attic. Power the Sonoff with the AC's (+)/(-) from the light box, then feed Sonoff's outputted (+)/(-) back to the light. Simultaneously, have the AC's (-) connected to the light like now, then still have it's (+) going to the wall switch and back to the light to turn the light on or off like now.

This is my wiring plan:

Would this wiring setup work to control the light with both Sonoff and the wall switch? If my diagram is correct, do I need the extra neutral wire going into the light, or is the one going through Sonoff enough?

Thank you!

First, everything about the Sonoff stinks like cheap Cheese, so good bet it is not UL listed.  RoHS and CE is nothing, and UL/CSA listings are often forged by those offshore manufacturers.

Mains electrical is serious business, and the stuff is already very cheap - $20 for a proper smart switch for instance.  The only reason that price seems high is you have found this thing that is cheaper in several ways, most bad.  Who cares? There will always be a cheaper piece-o-junk out there. Your time is valuable too.

In NEC jurisdictions you cannot install things not approved by your local inspector, who does not run his own testing lab, but simply gets a list of approved appliances from UL or similar entity. NEC 110.

You cannot mount outside a junction box

An electrical device cannot be mounted outside a junction box as you plan, unless the labeling or instructions tell you to install it that way - the labeling and instructions are part of the UL listing, the listing is contingent on it being installed properly, and it is illegal to install it contrary to those instructions (NEC 110.3).

Parallel switches in your plan are semi-OK

The fact that the Sonoff has netural coming in is simply due to the fact that it is a powered device and needs neutral for its own power.  Whether it is switching neutral, I cannot guess:  It may be possible to bypass its neutral output and serve the neutral from the other side - that depends (again) on the UL approved labeling and instructions on the device.

If that's the case, then having both the smart switch and the plain switch feed the light should be fine.   The key rule is that in any cable, currents must be equal - cancel each other out.  That is to avoid eddy-current heating.

Low voltage remote switches are even better

If Deepesh Golani's method of accessing the internal switch works, and (again) is supported by UL approved labeling or instructions, that is an even better way since it does not involve significant currents.   If that power is low voltage, you would escape the requirement to use Class 1 wiring techniques, and could run remote switches with thermostat wire for instance.

I don't quite get your diagram, this has been done by alot of people, the sonoff goes on the switch live out of the switch, so light switch stays on forevermore and you just use the sonoff to disrupt the flow of electric IE she goes on and off, but im UK and we have very different electronic setups so I could be wrong


Wire two 14-50 outlets to 50 amp breaker Was wondering can I add two 14-50 outlets to one 50 amp breaker using 6/3 wire and connecting with wire nuts?  Also, recommend PVC or liquid tight flex conduit?  Will be in the garage.

I want to add two electric car chargers.  Wire will come out of panel and to a junction box. From here, one 6/3 wire to one 14-50 outlet and another 6/3 wire to another 14-50 outlet.  Is this ok to do?  Only one charger will be in use at a time.  I have seen some wire nuts that can accept two 6 gauge wires but not three, which is what I will need.  Any ideas where I can find those?

Also, my HVAC guy gave me some leftover liquid tight so was thinking of using that but can also use PVC.  Any recommendations?

On 50A circuits, the rule is one breaker - one homerun - one outlet (NEC 210.23) The only exception is circuits which supply only cooking appliances (210.23C).  If you want to use two devices on one circuit, unplug the one you're not using and plug in the one you are.

It may be legal to feed two outlets with 2 breakers in a sub-panel.  However I would think an inspector would look askew at a 50A breaker in the main panel serving two 50A breakers in a sub-panel.

It would probably be allowed if you had an interlock which allows only one breaker to be on at a time.  Those are readily available, intended for generator interlocks.  Just backfeed them - this is allowed unless the breakers are GFCI or AFCI.  (and even if they are, move them around so they forward-feed.)

For wirenutting stuff that big, I use screw-down terminal blocks, they are more reliable.

I wouldn't worry about liquid-tight unless you actually expect water ingress.

I use metal conduit if the area is dry and unlikely to rust.  It qualifies as a ground path, so pulling ground wires is unnecessary.  As you may need to pull another set of 6 AWG... For 6 AWG wire, the hard max in 1" conduit is 6 wires.  Sure, that's pullable - if you have an electrician's truck full of special pulling tools.  But I don't, and I don't want to call that guy, so I wildly overbuild conduit. I use oversize conduit and lots of access points (junction boxes, conduit bodies) with no more than one 90 between them.  At that point I can usually just push the wire through, without fishing.

If you're running conduit, don't use 6/3.  That is sheathed multi-wire cable, informally called Romex, and it's stiff and miserable to pull through conduit.  You are not allowed to remove the conductors from the sheath unless they have appropriate markings of their own, which they won't.  The right stuff to use in conduit is stranded single-wire THHN (in dry areas) or THWN (in wet areas) - at 6 AWG size, most wire will be combo THHN/THWN.

See what your equipment requires.  If you're in conduit, and it doesn't need neutral, don't put it in - you can always add it later. You'd use NEMA 6 instead of NEMA 14.  Never use NEMA 10, it is obsolete.

Edit: I need more space to answer your comment.

From what they said on the website, Juicebox only needs 2 wires (plus ground). It is a modern style "switching" power supply which chops any input 110-250V into what it wants. What they call "red neutral" is only neutral in a 120V hookup, in 240V it is the other hot.  So, no neutral. Saved you a wire.  It is legal for Juicebox to wire their NEMA 14 plug with no neutral, I honestly have no idea if it's legal to not connect neutral on a NEMA 14 receptacle.

The website says two Juiceboxes have the intelligence to share a connection of limited current capacity.  That is not unprecedented.  Some washer-dryer combos are designed so the washer daisy-chains off the dryer, making it unnecessary to run a separate 120 service. The washer and dryer coordinate to not overload the 240V 30A circuit.  They are UL listed to do that if connected according to the manufacturer instructions.  Ditto Juicebox.

Over 50 amps, plugs and sockets are not allowed, you must hardwire the electrical connections.  Check a voltage drop calculator on the web for the wire size.  The site I used called out #3 Copper or #2 aluminum assuming a 75' run. However, you'd want to run aluminum anyway, because with large wires, metal content is a big part of the cost.**. When splicing this "big stuff" you use connection blocks with screws that typically use hex keys.  They're about $10 each at your local electrical supply house.  Grats, you graduated out of the big-box stores.  Never look back.

Breakers protect wires, so the breaker must match "the thinnest wire", i.e. The wire in the circuit with the lowest ampacity.  If that puts you between breaker sizes, you can go up to the next offered size, e.g. 80A. If you really want to run 100A wire, you can do that.

You have high aspirations and I would run conduit to match - no smaller than 1-1/2". Use larger boxes for working room... And think really hard about where your bends and/or conduit bodies are going to be. That big wire will be stiff.

**The infamous problems with aluminum wiring pertained to an alloy now outlawed, being used for small lamp and outlet wiring. That doesn't save any money, because in small wire, little of the cost is mineral value. It was done post-war because it was simply impossible for the surviving copper mines and smelters to satisfy post-war demand.

Q: can I add two 14-50 outlets to one 50 amp breaker
I read a lot of NEC Article 210, and focused on 210.23. I see no restriction on outlet count. I have to conclude: you can have two or more outlets or receptacles on one 50 amp breaker.
Everything else about Harper's answer is great advice (although I personally think going above 1 inch conduit is a bit much). I would have just commented on his answer, but I'm not allowed to comment.
The section of the NEC he references doesn't restrict the number of outlets on a 50 amp breaker. If you interpret the permissible load as a restriction on outlets, then no circuit breaker in the house can have more than one outlet on it and you have to ignore that the section is exclusively about multiple-outlet circuits.

National Electrical Code 2014
ARTICLE 210 Branch Circuits
210.23 Permissible Loads, Multiple-Outlet Branch Circuits. In no case shall the load exceed the branch-circuit ampere rating. A branch circuit supplying two or more outlets or receptacles shall supply only the loads specified according to its size as specified in 210.23(A) through (D) and as summarized in 210.24 and Table 210.24.

This section is actually about multiple outlet circuits and the load they are allowed to carry. So a 50 amp branch circuit must only carry a 50 amp load. This is ensured with a 50 amp circuit breaker.

210.23(C) 40- and 5-Ampere Branch Circuits. A 40- or 50-ampere branch circuit shall be permitted to supply cooking appliances that are fastened in place in any occupancy. In other than dwelling units, such circuits shall be permitted to supply fixed lighting units with heavy-duty lampholders, infrared heating units, or other utilization equipment.

So immediately, this says nothing about restricting outlets. In fact, it's actually defining what "fixed" or "fastened in place" loads can be wired to a multiple-outlet (210.23) 50 amp circuit (210.23(C)).
Let's look at the referenced table too.

Nothing about only 1 receptacle. It references back to 210.23(C) for permissable load, but that's not a discussion of how many outlets can be on the circuit.
Here's how I think about it: An outlet is not a load. It is only the potential for a load. 210.23(C) discusses connected electrical devices (lights and stoves) that put an actual, defined load on the circuit. That's why it doesn't mention outlets.
The circuit breaker protects the wire, outlets, and a device plugged in from over drawing current, over heating, and starting a fire. If the circuit breaker protects at 50 amps, then the wire and outlet must be rated to handle 50 amps. If two 50 amp devices are plugged into two 50 amp outlets on the same 50 amp CB, and those devices actually draw full 50 amps (rare) or above 25 amps each, and they are used at the same time, the CB will trip. That's it's job, to protect the wires. And presumably the user won't plug too many devices in again.
This is the design of almost every circuit in your house. (There are exceptions for the small-appliance branch circuits, outlined in 210.11(C)) Multiple outlets are on almost every breaker. If you plug in a bunch of space heaters, you will trip the breaker, but the wiring will be protected.
Having said all that, check with your local inspector.
While I'm here, I might as well complete the answer... although Harper's answer perfectly covers everything else.
Q: using 6/3 wire in conduit
Don't use 6/3. You need THHN for conduit.
3/4 inch EMT conduit can take four #6 AWG wires. Code requires no more than 40% fill of EMT (NEC Chapter 9), so you can calculate this yourself. I haven't looked up PVC, but if you use 1 inch PVC, you'll be good and it will be a lot easier to pull.
Another tip: The ground wire is not considered current carrying and can be smaller. (2014 NEC, Table 250.122) For a 50 amp circuit, you can use a #10 AWG THHN copper wire. This will save some money and make pulling much easier.
Q: I have seen some wire nuts that can accept two 6 gauge wires but not three, which is what I will need.
Use terminals blocks or "polaris connectors." Search for polaris connectors online, and you'll get a lot of results.
Q: recommend PVC or liquid tight flex conduit
I would use EMT. I've seen PVC sag a little with time, so I think EMT looks better. Also, you might be able to use it as the ground return (although I would feel safer with a ground wire).
If it must be PVC or liquid-tight, I would go with PVC, but I haven't used either in a long time. Liquid-tight might be more expensive to get fittings for and it might be more difficult to install.


Is a butt edge to tapered edge drywall joint OK? I’ve got some smaller areas I need to fill with drywall in a room, and fortunately I had some pieces from cutting others while staggering. I used them to fill in the gaps, but I didn’t like how they looked as they were butt edges against tapered edges. I took them down and used a fresh sheet to ensure all tapered edges met.
However, I feel like I wasted an entire sheet just to achieve this. Is it fine to have a butt up against a tapered edge?

It depends how fussy you are. A perfect finish is easier if you have the only joints at tapers and corners.

What I do with butt edges, which also come about when you're putting in a drywall patch, is to peel off the outer most layer of paper on the drywall about 1" or so back from the edge on both the pieces.  Then just apply mud, joint tape, and mud like you would for a taper joint.
If you peel off too much paper, then you're liable to have an edge show where the peeled off section meets the un-touched drywall.


What type of bathroom window for max airflow? I don't have fans for ventilation at the moment and may choose not to have but I have big windows in bathroom. What type of window should i install? The common ones here are those rectangular ones that open from the top, with hinges at the bottom. The window swings open to inside.

The best types of windows for airflow are double hung windows ─ ones that open from the top and bottom. The top part lets out hot air and the bottom part allows fresh, outside air to flow indoors. This works especially well if the top window is near the ceiling, say, within a foot. Windows that open only at the bottom don't really allow a lot of airflow, since they don't allow any air exchange.Edit: If having windows that allow for good ventilation is important to you, then you should invest in one of the following window styles:
•Single/Double Hung
•Casement/Hinged
•Awning or Hopperfrom http://schmidtroofing.com/best-windows-natural-light-ventilation/AndWith a double hung window you can open the bottom and top of the window at the same time. This allows cool air to enter the bottom and hot air to escape out of the top. It makes it possible to ventilate a room using just a single window and to do it effectively. When trying to ventilate a room with single hung windows you need multiple windows in order to create airflow, and they still aren’t as effective as double hung windows at getting rid of warm air.from https://modernize.com/windows/types/double-hung-windows

I'm going to post this as an answer, even though I feel your question is one that cannot have an answer.

A: One that opens

Everything else is subjective. Your environment (wall opening facing N S W E? Location on planet, mountains, valleys, near external water?) plays a big part in this. If you live in a 4 seasons climate, using "just a window" is foolish. Even if it isn't a 4 seasons climate, a cold night, or a hot muggy day, and having max airflow is a BAD THING.

Generally speaking, opening a window of any "normal" size, in a bathroom with a shower for example, is more than sufficient for almost any bathroom unless its a steam room. Of course, the window has to be NEAR the water sources, within reason.


If metal expands when heated, how does heating a bolt loosen it? If you're having trouble removing a stuck bolt, common advice is to heat the bolt up.  But if metal expands when heated, wouldn't heating up the bolt just make it harder to remove? How does heating the bolt get it unstuck?

The answer is surprisingly simple: the bolt expands, but the nut expands more.

What is happening here is good old thermal expansion:

The bolt is heated and expands outwards, its radius increasing
The nut is heated and... expands outwards, its radius increasing

Now, since the nut's radius is slightly greater than the bolt's, and since the increase is proportional to the rest length, the nut expands a little more.

Iron has a thermal coefficient in the 10-5 / K ballpark. It means that for each 1 K increase in temperature you have an increase in size of 10-5: a 1 m rod becomes 1.00001 m long.

If your bolt has r = 1.5 mm, and the nut has R = 1.501 mm, what happens is temperature is increased of 500 K? Well:

r = 1.5*(1+500*10-5) mm = 1.5075 mm
R = 1.501*(1+500*10-5) mm = 1.508505 mm

As you can see, before heating R - r = 1 μm, while after R - r ≈ 1.001 μm. It increased!

Please note my numbers are quite wild and used just to make an example. I am sure that I got the starting values wrong, but I hope they help to get the message across anyway.

Put a penny in a door jamb and close it. The door will be almost impossible to open, because friction will hold it in place. The flexing of the rest of the door will prevent it from moving. A rusted bolt is essentially the same principle - many small bonds formed on the threads of the bolts by oxidized metal prevent it from turning.

The heat and expansion of the metal simply served to break those bonds. It has nothing to do with thermodynamics or any other science-y nonsense. It is the simple mechanical action of the expanding metal breaking the rust.


What type of wire for sub panel to detached shed in Colorado? I am getting so many different answers on what to run to my detached shed. I am going to pull permits soon and have it inspected before hand - but im trying to blend in the codes for what it is allowed in Colorado

So, I am building a 200 sqft shed that will power up around 5 or 6 outlets along with 3 security cameras, power tools such as table saws, circular saws, battery chargers etc.

ive been told to use a double pole 30 amp with UF 10-3 wire to feed my sub-panel (which will be 70 amp sub panel) The sub panel is going to have 2 x 15 amp circuits and 1 x 20 amp circuit for my tools.

I also been told to run a 70 amp with number URD #4 cable (4 wire) to feed the 70 amp sub panel.  I am not sure if thats overkill, or if that will give out TOO much power to my 70amp sub panel and if that will be too dangerous?

So, my shed will be about 70 feet from my main panel, so I will have to dig a trench. I was also told not to use a conduit (pvc pipe) for the UF rated wire - instead it will be bare burial. is that code?

Use a fat conduit and appropriately sized THHNs instead

Direct-bury wire (UF) is vulnerable to excavation damage and difficult to upgrade if you want more power at the shed later.  Hence, it's better to slap a fat PVC conduit in now while you're digging the trench for the first time -- conduit's cheap compared to the cost of renting a trencher.  Inside the conduit, you'll use 3 THHNs of appropriate size and color for 2 hots and 1 neutral (voltage drop control will likely mandate a larger size than the 10AWG minimum you were thinking of) as well as an appropriately sized bare copper ground (10AWG for a 30A feeder, 8AWG for a bigger feeder up to 100A) wire.

Don't skimp on the subpanel either

Buying small electrical panels is penny-wise and pound foolish as a larger panel now is always going to be cheaper than upgrading later.  I'd recommend a 100A/24slot subpanel at a minimum here (you can always feed a large subpanel with a small feeder, just not the other way around -- remember that the protecting breaker must be the bottleneck so it can keep you safe from overloads). You'll also need a main device (it can be a breaker or a molded-case switch) at the subpanel to serve as a disconnect switch for the shed in addition to the breaker in the main panel protecting the feeder.  (That's so you, or the FD, can shut power to the shed off quickly if it catches on fire -- "firemen don't deal with wires" after all.)

Last but not least, you'll need a ground electrode (Ufer ground if you haven't poured the foundation yet, rod if you have and need something you can put in now) in addition to the grounding wire -- the grounding wire provides a fault path (safety drain) back to the source while the ground electrode dissipates built-up static charges, induced voltages from lightning, and the likes.  Don't forget to pull the bonding strap or screw from the subpanel when you put it in!

It is always best to use copper over instead of aluminum yes it is more expensive but we are talking about safety of people not burnt by fires and shorts and arcing that happens alot more in aluminum and hardly ever with copper why risk a fire  or death it is a proven fact by fire fighter that when it comes to electrical fires in homes most of the time it was caused by an aluminum wire connection of dissimalar metats or the instability of aluminum with heat in the current with expansion and contraction causes the connection to come loose arc and spark causing a fire even if it was not dissimilar metals


Bedroom not getting enough heat I have a dedicated HVAC unit for the rooms on the second floor of my house.  A bedroom at the opposite side to where the HVAC unit sits doesn't get enough AC or heat.  Right now, in winter, that room could be 10 degrees cooler than other bedrooms on the same level.  I confirmed the vents are open in the room.  It seems not enough hot air is reaching that room.   What could be the problem?

There's a supply vent that seems to disproportionately and needlessly heating the hallway and top of the stairwell.  I tried to close the vent but that didn't improve the situation in the cold bedroom.

Try closing all of the other vents, this should blast that room. If not, then that room's duct is either grossly improper, has a blockage or the ducting has separated. If it does blast that room, & hopefully it does, then you'll want to keep that configuration for the most part. It's called Balancing & you'll want to just crack the other rooms & hall to a little bit more open for an equal or Balanced distribution or you may find that just 1 vent (hall) really affects the Balancing. You'll have to remove the grills that don't close & block them with cardboard inside the fully re-attached grill for testing or Balancing & also to repair their operation or replace them.

Could be your system (vents) need cleaned


What is a strong glue for bonding metal? I have a (cheap) garage door that has the metal frames/hinges connected to the actual metal door by some kind of glue.  The glue on one part of the frame has broken off.  What is a glue that is strong enough to hold 2 pieces of metal together?  This is about a 1.5 foot length of metal that is about 1/4 inch wide.  The garage door opener connects to this piece so there is quite a lot of push/pull and vibration, so it needs to be very well bonded.

This-to-That recommends JB-weld or LePage's Metal Epoxy.  I've never used either, personally.

The important thing for this is going to be surface prep and clamping, I would assume.

You might be able to use a CA glue (ie, "super glue"), but you'll need additional reinforcement to keep the bond from shearing (eg, glue then bolt it in place, but 1/4" is kinda narrow to bolt through; also, I have no idea what sort of clearance issues there might be if there are bolts sticking out)

Try Gorilla Glue; it bonds to everything.


Smoke alarms go off in the middle of the night for no apparent reason and then is fine Tonight at about 2 AM my wife and I were awakened by our fire alarm system going off in full alarm mode. I quickly jumped up and pressed the button to reset the system and they all stopped. We checked the house and everything was fine. We had the same thing happen about a year ago, again in the middle of the night.

Our house is almost 3 years old. We have 8 fire detectors and one carbon monoxide detector. The carbon monoxide detector is in the basement near the furnace. The are all hard wired together and have battery backups.

Is this normal? Should I be concerned? Do I need it checked by a pro? What may be the cause? Are we haunted?

You may have batteries getting old. You need a battery tester (not expensive). Even new batteries can be faulty, and supply low voltage to an appliance. This will cause a fire alarm to false-trigger, sometimes.

Town could also be switching grids.  Happened to me 3 years in a row just after batteries were changed.


How to remove water based wood stain splashed onto painted surface How do I remove the water based wood stain from my kitchen wall. I got some on my kitchen wall while I was staining my kitchen cabinets?  I tried to remove my using soap and water on a sponge. It did not work. My kitchen wall is painted with water based satin finished paint.

The primary difficulty you are facing is that virtually all paint is somewhat porous, water based paints generally more so than alkyd (so-called oil) based paints. It is complicated by the fact that the stain that has been added is also water based. While there are plasiticizers in water based paints used to make them more stain resistant, these only partially prevent absorption of staining materials.

Soap and water is a good first start for most stains (after gentle blotting). The next step is usually a stronger detergent based cleanser, such as Fantastic. A test should be made on an inconspicuous area before trying any cleanser. If the test does not indicate serious compromise of the paint, proceed to attack the stain.

First put a bit of the cleanser on a paper towel or clean rag, and try rubbing the spot. If that does not work (or work well enough), try spraying directly on the stain and rubbing with the paper towel.  If some stain is being removed, keep turning the towel or rag to a clean area as you work. If this works, wipe the area with plain water when you are done.

If this does not work, you could try solvents, such as alcohol, mineral spirits, or acetone, but any of them are almost certain to compromise the finish. They also give off serious fumes and need to be handled with care.

Even the gentler detergent based cleansers may leave the paint with a different sheen from the rest of the wall. If the area is small and near trim, it may be worth dabbing a bit of matching paint over the stain. Depending on how long ago the wall was painted, it may blend and match well. If not, you may be facing a repaint of the section.


Electrical - GFCI tripping I was replacing an outlet in my bathroom with a gfci outlet. When I throw on the power, it trips but not only that, it takes out a set of lights over the mirror which are connected to a double switch on the wall. The other switch is fine. What should I be looking for to fix this issue?

Because "continuing the circuit" is a completely different thing than "placing a load inside the GFCI's protected zone". Especially where switches are present!

I get it. You've installed receptacles for decades.  You know (other than split receptacles) the extra 2 screws on the receptacle are for continuing the circuit onward.

Now you also know there are some receptacles (eg. USB) that only have 2 supply terminal screws.  They do not provide any method for continuing the circuit onward.  With those, you are forced to pigtail the receptacle and use a wirenut to splice its supply with the onward wires.

GFCIs are like that too, GFCIs only have two supply screws.  They are conspicuously marked LINE and they are the only terminals not covered with warning tape.  (The warning tape says, in so many words, "For Wizards Only".)So, similar to a USB, these should be pigtailed with a wirenut for continuing the circuit onward.  Only the LINE terminals should be used.  This is especially true in a retrofit situation like this, and double especially when there is a switch in the same box.

Everything I have said so far is about continuing a circuit onward, which is what you are trying to do.   Now we're going to turn the page.

GFCi devices come in several packaging styles.  There,s the GFCI+breaker, the plain GFCI deadfront, and our friend the GFCI+receptacle.  All of them provide a "GFCI protected zone".  Obviously, on a GFCI+receptacle, the protected zone is the built-in sockets.

However, all of them can extend their zone of protection beyond the device itself. (That'd be kinda necessary on the breaker and deadfront, eh!?)  How to do that is beyond the scope of this answer.  But you may know a rule that currents must be equal in any cable.   That rule applies in spades to any GFCI zone of protection.  This makes it rather tricky to work with them in switch boxes.

However there's generally no value or benefit to putting hardwired bathroom lights, fan, heater etc. on a GFCI.

Bottom line, pigtail everything to LINE and call it good.

I am afraid I have to respectfully but strongly disagree with the idea that removing the load from the GFCI protection is an acceptable solution.  That's along the lines of putting black tape over the OIL light on your car's dash so you don't have to deal with the irritating red glow.  It's better to at least try to figure out what's going on and see if there's a potential hazard.

There's a reason GFCI protection is required in bathrooms, it's a place where faults are more likely to be dangerous due to proximity to water and plumbing.  GFCI's trip levels are tiny but so are the actual voltages that can harm a person.  Even a mind jolt in the bathroom can be dangerous - even if the zap doesn't do much damage, the fall might.

I'd first test the receptacle itself.  Temporarily remove the load wires and cap them, and see if the GFCI will hold with no load.  If it holds, plug in a load - something simple like a lamp - see if it holds.  If it holds, see if it trips as it should with a GFCI receptacle tester.  (If you have solenoid voltage tester, you can also test a GFCI by testing voltage from hot to ground - the load of the solenoid should trip the GFCI.)

At that point I'd replace the load wires and see if the GFCI still trips.  If so, disconnect and cap off the downstream loads one by one.  If you determine one of the loads is leaking voltage, you can decide whether to replace it or run it without GFCI protection.

If it trips with all the loads disconnected, that points to a wiring fault, which is bad news - it may be difficult to track down - but it is potentially dangerous, and should be corrected.


How do I fix a garage door opener light that loosens in its socket? The light on my garage door opener keeps getting loose in the light socket, causing it to not work. Giving it a slight turn to tighten it fixes it temporarily, but it comes loose again within a week or so. I'm assuming it's the vibration of the opener that's causing the problem.

How can I prevent the light bulb from coming loose in the socket?

First unplug the opener. Now look in the light socket. See if the small metal tab at the bottom is nearly flat. Carefully pull it up a little bit so it applys more spring tension to the bulb. Also, they used to sell "rough service" Incandescent bulbs for openers, but I have had OK luck with compact fluorescents.

Try wrapping the threads on the light bulb with Teflon tape. That will give the bulb a snugger fit in the socket.


How do I troubleshoot power receptacles? I just bought a recently renovated house and the house inspector said that all the plugs in the basement worked.

Well... I plugged in several devices into the plugs and they don't power on. If I use my voltage tester I can see that the plugs are indeed 'hot', however they do not actually provide any juice.

All of the affected plugs are on the same breaker as well as the lights for the basement. The lights have no issues turning on.

What are some steps I can take to figure out what the problem is?

Update:
I opened up one of the plugs to see if there was anything visibly wrong. All of the contacts appeared to be wired correctly. I swapped out the receptacle for a new one I had purchased and I wired it into place. I attempted to plug a small test lamp into the new receptacle without fully screwing it into place and a bolt on the hot side that wasn't fully tightened brushed the side of the metal box thingy and caused a spark! eep! I'm guessing that means the power and the ground are working. I turned off the breaker and screwed the receptacle in properly and tried the lamp again and still nothing.

Update 2:
I purchased a receptacle tester and the receptacles all show blank, yellow, yellow which seems to indicate that they are wired correctly. Next step I will hook up a volt meter.

Update 3:
Ok I plugged in the multimeter and it only goes to 30... to make sure my multimeter wasn't out of whack I plugged it into my working outlets and the needle went to 120V. Soo, for some reason I only have a quarter of the voltage I should have, weird.

Update 4:
Resolution, so I caved and hired an electrician.
It turns out the wiring for the plugs ran through a light fixure. Inside the light fixture all of the neutrals for the plugs were wired to each other, however, they were not wired to the main neutral!
The electrician screwed a wire nut on the 2 bundles and low and behold, working plugs everywhere. Thanks for the help everyone!

As I said in the comments to the OP and to Aaron's answer, there are several wiring failures that could cause an NCVT (non-contact voltage tester; usually a pen-looking thing that beeps when you point it at a live electrical wire) to light up, and some that even a plug tester can miss, but that would prevent a "real" load from being plugged in. The first thing to do is get a 3-lamp outlet tester (preferably with GFCI testing) to supplement your NCVT. The tester will correctly diagnose most of these things:

Open Hot: the black wire is present in the box but disconnected from the plug (or otherwise not making good contact). An NCVT can still light up if the wire is close to the faceplate. However, a plug tester will diagnose the issue. The fix is to flip this outlet's breaker, open up the plate and make sure all wires are firmly connected to the proper terminals on the outlet.
Open Neutral: the white wire is present but not properly connected to the outlet. Again, a NCVT will light up if the hot is properly connected (maybe even if it isn't), but a plug tester will properly diagnose the issue. The fix is the same as for an open hot.
Broken/Worn/Bent Outlet Contacts: The wires are hooked up correctly, but the outlet's contacts have poor or no continuity with the plug's blades. You may hear arcing (a rough crackle) as you plug in the tester or an electrical device. A tester MAY show correct wiring at a glance, but if you jiggle the tester the lights will blink off. Replacing the outlet is the solution here.
Neutral-Ground Swap and High-Resistance Ground: This would tend to affect an entire house's wiring, but it can be localized as well. What is happening is that the white and bare wires have been switched, and in addition, the ground (which normally ties back to the bus strip in the service panel and has full continuity with the neutral) has lost some continuity back to the service panel. There are several situations in which this can happen, most of them involving attaching grounds to house plumbing and then changing that plumbing along the way. An outlet tester may not diagnose this; the expected read is an "open ground" or "open neutral" (remember this would mainly be a problem if the neutral and ground are switched), but if there is some continuity then the tester may not show a problem.
Poor Continuity Of Hot Or Neutral With Outlet: One or more wires is making very poor contact with the outlet terminal. A plug tester may miss this; there is enough continuity for the tester (which only draws a few milliamps for its LEDs) but even a clock radio would have issues with the load induced by the poor continuity. The solution is to rewire the outlet securely, and if the wiring is sound on the plug then to check other wires in the box (with the breaker off of course). The next most likely culprit is the "bundle" of neutral leads that's normally in an "upstream" J-box; make sure all wires are wound tight and properly secured with a wire nut and electrical tape.

Sounds to me like your plugs could be connected to one of the light switches meaning that when you turn on a switch it will operate the plugged in appliances as well; some people do this when you do not have a decent light source in a certain area they can plug in a lamp and use the switch to turn it on/off or a radio or something of that nature. Test the light switch with something plugged in this may answer some of your issues.


Can landscape adhesive be used for a masonry fire pit? I'm building a fire pit...Just like in this video.

At 1:40 he is using an adhesive (looks like versa-lok concrete adhesive).  I didn't think it was needed, but I like the idea.  I thought video would use it on the base, but they use it only on the courses.
I didn't see anything about high heat in on the tub.
Is it effective under heat?
Can something like this give off dangerous fumes when heated?

Regarding Loctite PL 500 landscape adhesive (mentioned in the asker's answer)...

Service Temperature: -20°F (-29°C) to 150°F (66°C)

No, landscape adhesive (or at least that specific product) isn't rated for temperatures encountered in a fire pit.
That said, if you put a bead toward the outside of the course rings I'd expect it to hold up fairly well. Temperatures out there may get high enough to soften it, but probably wouldn't burn it.
Of course, there may be landscape adhesives (or products that could serve as such) with higher temperature tolerance.

I talked to a sales person at a hardscape place.
He gave me:
Loctite PL 500 landscape
EDIT:
I used the PL 500 Landscape adhesive towards the outside and it's solid.


Should I peel off the top layer of vinyl in preparation for tiling? I'm preparing my kitchen floor for ceramic tile. Currently it's a sheet of vinyl(linoleum?). The plan was to sand off any gloss and tile over it. I was going around the edges picking off any loose areas and I noticed the top layer of the floor is peeling off and leaving behind a paper like layer which looks to be glued to the original vinyl floor. So it seems the vinyl layer is splitting in half. What would be the better surface to tile on? The paper like surface or the sanded vinyl? Please don't recommend pulling it completely off as that is out of time and budget.

Unfortunately, you NEED to remove or cover the old vinyl. If you attempt to tile over an unsecure base, you are wasting yout time and money because the tile will not stay down. In your case, if you go over the splitting vinyl, the vinyl will continue to separate and up will come the tiles.  If you go over the paper layer, the mortar/quickset will not stick properly. If you don't want to strip everything, which is a very thankless job, and your subfloor may not be the greatest either,  then screw down a layer of Hardi-backer. Hardy-backer or concrete board is the perfect base for your new tile.  Good Luck

Look - I understand you need to do this quick and you know its wrong to put on vinyl. You came and asked a specific question and I though about it (out of the box) I got your answer. This is not the correct way as pointed out by your self and everybody else.. but you already knew that.

You might even get away with this  for long term solution. You selling quick? moving out form rented place? Doesn't matter. You asked how to lay tiles on vinyl. I will tell you how!

If you going to be doing it the wrong way, you might as well do it a little bit right to make it last longer!

You had a good idea with taking the gloss off, don't take too much time sand papering it. Just scour it but don't penetrate it. You don't want water to get to the paper under it. You will get some kind of rot and bad smell.
You need to secure the vinyl so that movement wont cause cracks in grout and make the tile come loose.
It is not easy but what you can use is some kind of building mesh - very thin and it doesnt need to be wide. It can even be some kind of builders wire(the stiff stuff)

It will be quite expensive to lay the whole floor with this. So at least cut it into strips or get you local DIY store to do it for you. Run a strip 2cm-3cm length wise so each tile comes in contact with this.
Because you got concrete under there you will have to drill a few holes and attach the mesh and wire in certain areas with screws, tightly! so it doesn't pull away(upwards easily) sideways does not matter.
This isn't the best drawing but it illustrates what you gotta do. Black squares the tiles, orange is the mesh/wires, blue is like the screws/bolts fastening.

What is critical here the the mesh strip or wire does not pull upwards too easily. You will then lay mortar as usual and on top of this wire taking care that the mortar wraps around, sits inside the mesh nicely.

The mortar will still NOT stick to the vinyl but what you have created is a superficial surface that reinforces the mortar and will help the tiles disperse weight and stress over larger areas with out cracking. Because the mortar hardens it will keep the mesh from moving sideways that is why it must be fastened in a uniform way so it does not lift up. That is the key here.

NO  This is not the the correct way to do it - you know that - If you finish it off nicely and let it set properly it should be OK.

Liberty is painfull....


When installing hardwood floors, should I use rosin paper, roofing felt, or nothing underneath? Why? I've installed hardwood floors, over top of OSB subfloor with a layer of roofing felt in between.  I copied this from the hardwood floor contractor who did a kitchen in my home once. He'd been in business for 20 years so I trusted him.  I think he said it was to prevent squeaks.

Is this true?

Does roofing felt used in this way also provide a vapor barrier, and if so, why is that important under hardwood?  I can understand why it would be useful on a roof.  I can understand why it would be useful for housewrap.  Under a floor?

I read elswhere that rosin paper was originally used to keep floors clean (protect from the dust from drywall finishing, for example), and make it easy to slide floorboards. That seems pretty minimally valuable. Do I care if my OSB gets dusty?  I usually shop-vac the OSB before laying down the floorboards, so is this really a benefit?  And using rosin paper to ease sliding boards during install?  Really?  I never noticed a problem sliding the boards. Is this because I'm really strong?  (not likely).  Maybe it's because I'm using OSB as a subfloor which is a pretty smooth surface? I can imagine using plywood as a subfloor, in the days before OSB, might/could cause hitches when sliding boards during installation.

Do either of these layers provide sound-deadening or anti-squeak qualities?  I figured the lack of squeaks was from using a sound, level subfloor, and installing the T&G tightly.

This question gets asked a lot in various DIY or even contrator forums.  The problem is, there doesn't seem to be a general convergence to a single answer.

OK here we go. First of all, the most common reasons for squeaky hardwood floors are age and installation over uneven subfloors, where any movement of wood on wood makes the sounds. Age becomes a factor when the subfloor ages, shrinks a bit making the nails holding the hardwood a bit loose. Adding either a layer of felt or rosin paper isolates the wood layers and helps to minimize squeaking  wood to wood. A lot of the squeaking on older floors are actually the nails moving in the subfloor, so today we use threaded nails, and for the most part and that solves that problem.  So in your case, it certainly can't hurt to use some paper.  Good luck.

None of the above. You should be using a pad designed for flooring; it prevents squeaks, insulates your floor and on the higher end pads, has a moisture barrier built in. The padding is more expensive but worth it. If you decide to go without, silicon paper is the minimum underlayment you want.


Remove garbage disposal piece in bottom of sink I am replacing a new sink in my kitchen and this piece is from the garbage disposal

Do I just break the glue / putty free and pull it out?

You need to loosen the 3 screws that push the collar (top piece in your image) against the bracket (bottom piece) into the sink. Once that is done, a lock ring will be visible (underneath where the collar currently sits). Use some pliers to remove that, and then all the pieces on the underside can be removed. You can then break the putty / silicone to remove the gasket from the drain hole in the sink.

All that said, if you're tossing the sink, it's much easier to just buy a new garbage disposal installation kit, which contains all the pieces shown in your image. Install the new kit on your new sink, and then install the old garbage disposal on it.

You can, or you can pick up a new one at your local big box DIY store. There are a few different variations but that one looks like a common one to me. Either way, you will need some plumbers putty to install the new one.


Painting Over Old Walls The stairway in my mother's house has been unpainted for a while. I recently asked if she wanted help with it, and now I'm out of my depth.

There's a layer of old wallpaper that she and my brother started removing a while ago. It took forever and left a rough brown residue (first picture.)

Another area appears to have been plastered over at some point (second picture.)

There are areas where this wallpaper seems like it would be very difficult to get off, and other areas where it's crumbling off.

After some research online it seems as though scraping and sanding are definitely in order, but after that some sources suggesting using lining paper to cover minor bumps. Other sources have said that this isn't what lining paper is for. My questions are:

Am I on the right track? Is there a standard way to handle this?
What is lining paper and will it work to cover minor imperfections
before painting?

I feel your pain.  In some rooms I had 2 layers of wall paper and the upper layer had been painted - SWEET.. yeah!

I have had your issues tried the sanding methods.. I tried joint compound to fix the imperfections, and used flat paint - that kind of works - but lots of work and not perfect.

For how much wall are you talking about I would pull the old drywall and replace with new - Faster, Cheaper, Better.

Assuming you are in the USA The drywall will set you back $10 a piece, and the joint compound about $8. Joint tape about $6 . Given it is a stair way there probably is not much dry wall ..

After my experience here is my opinion: I would Remove and Replace (R Square for short) the dry wall with new as I think it is faster, cheaper and will turn out better and you should be able to use any sheen paint you like.

EDIT

To answer the question about the liner..

Basically a tape product - personally I wouldn't use it.

You can however sand and then use a thick primer to cover up small imperfections.
Just don't expect thick primer to go on like paint - it doesn't, it is work - but for stairwell maybe you take the plunge - worth a shot anyway but will cost you some green for that primer.

To help you understand the process a bit more I attach a video for a drywall surface repair. As a preface to the video so you can understand the purpose and reasoning behind how it is done. In the video the reason for the thick primer is to keep the fibers down and have a surface suitable for the joint compound. It works but can be tedious depending on how much area has to be fixed. The sanded areas of your wall - well you get the idea from this video that it works similar except you are not adding joint compound over those areas.

This video will give you an idea of some fixes
Dry Wall Paper Repair Process using thick Primer

If you dont want to replace drywall, o suggest using a texture and just put the texture over the entire wall
 You can make designs on it, while wet and that should cover any imperfections.


Can I add a 30 amp breaker to a sub panel being fed from a 50 amp breaker I have 100 amp service panel that feeds a sub panel with a 50 amp breaker. In the sub panel, there are currently five 15 amp breakers that feed three rooms worth of lights and two outdoor outlets used to run 2 Christmas light controllers. All lights are LED and there is a celling fan on one of the breakers. I need to add a 30 amp breaker for an electric in-wall oven. Can I put this breaker in my sub panel, or should/must I make room in the main panel for this breaker?

Assuming you've got 6 gauge wire feeding the sub panel, you should be fine. As long as you aren't pulling more than 50 amps through that sub panel at once, you don't need to worry about over loading the panel. That's what the 50 amp breaker is there for.

it sounds like your 100A service is full and your sub would be over loaded with an oven of that size on bkr count , it could be done if the load was measured and low enough not to be a problem (with all the led & christmas lights on ect),however I would think about a larger service.I stand by my original statement with a 100A main a 30A oven what about waterheater, furnace blower, refridgerators, washer and dryer. these all add to the load that was not discussed, a 100A service panel is very small by todays standards and they have already added a 50A sub, I am a licensed electrician and I would not be pushing a small pannel that far knock me down more i really dont care I am trying to keep someone from burning thier house down.


Switching 3-phase power between two appliances using a 3-phase switch In my garage I have an electrical 3-phase dryer.  I want to add a new 3-phase  air-conditioner. I want to be able to switch between the two of them, by using a 3-phase switch. This way, only one of these two appliances, can work at any given time.  In the market, such switches, for residential use are already available for purchase.

I was told by two electricians that I am not allowed to install the switch, because such installation is a violation of the building code. My questions are:

Is my proposed installation of a 3-phase switch a violation of the building code?
If the answer is a 'YES', then why is it so?
If I cannot use this switch, what are my legitimate options to make the dryer and the air conditioner able to only work one at a time?

I really don't know why you couldn't. If the switch is made for residential use for that purpose I don't see why not. They said it was against the building code? Not the electrical code? I could not see why the carpenters would care what the electricians did (building code versus electrical code).


How do I stop lights from flashing when I turn on my table saw? I just installed a hanging fixture for two 40W T-12 fluorescent bulbs over my table saw. If I power up the saw when the lights are on, they flash off and come right back on (after the usual flickering). The saw is 1.75HP, 110V, 14A, and the circuit is 20A.

The receptacle currently powers the table saw from one outlet and a 1.5HP dust collector and the light fixture plugged into a power strip from the other outlet.

I know there is a big draw on the house's power when I turn on the saw, but this is a pain. Can I plug a UPS or other voltage-stabilizing device in front of the lights and dust collector to make this go away? Should I plug all the devices into a UPS? Or, should I deal with it and stop whining?

Thanks!

When an electric motor turns on, there is a thing called "inductive kick". What this means is that for a second at start up, the motor looks like a short circuit and draws more than the rated amperage. Voltage is dropped as well. This is corrected by huge capacitors in an industrial situation. In your case, the combination of large current drain and a resulting voltage drop causes the ballast for the florescent lights to fail to deliver proper voltage to the bulbs.  This is common.  I would move the plug for the lights to another circuit. The only other thing that will cure the problem is a motor starting capacitor.

I believe that the lights are cutting off because the motor is drawing all of the available current when it starts. In other words, the lights which are on the same cicuit are being deprived of power. If you use a variable frequency drive (VFD) to control your motor, then the motor will only be allowed to draw a limited amount of current.

From wikipedia: In starting a motor, a VFD initially applies a low frequency and voltage, thus avoiding high inrush current associated with direct-on-line starting.


How do I install a GFCI receptacle with two hot wires and common neutral? In my kitchen, I want to replace a regular 120V receptacle with a GFCI-protected receptacle. The instructions describe what to do with a regular 2-wire + ground feed, with and without daisy chaining to other receptacles, but not how to do it with a 3-wire + ground feed. Please describe how I should connect the new receptacle.

Here's a diagram of how the non-GFCI receptacle is currently wired, in my best 6-year-old artistry:

I think it's connected this way so that each receptacle in the kitchen has their two sockets supplied by different breakers. At the service panel the circuit is controlled by a joined pair of 15A breakers. I assume the white and black are separate 15A lines and the red is a common neutral (?).

Here are the instructions for connecting in a 2-wire scenario.

How do I connect this? Or should I consult an electrician?

EDIT

From The complete guide to home wiring

The first problem is that you may be using the wrong cable and breakers.  NEC calls for 2 20Amp small appliance circuits in the kitchen, to accomplish this you'll need to switch to 20Amp breakers and #12 wire.

The next problem. You'll have to pull new wire anyway, if you want to hook up GFCI receptacles. GFCI receptacles will not work properly with a shared neutral, you'll end up with nuisance tripping with a shared neutral.  GFCI receptacles work by monitoring the balance between hot and neutral, so if the neutral is shared the GFCI will not work properly.

To wire up the kitchen properly, you'll have to pull 2 new 12/2 cables from the breaker to the kitchen (all #14 wire on that circuit will have to be replaced). Then install 2 20Amp breakers, to supply the kitchen.  You'll install the GFCI's as the first receptacle on each circuit, which will protect all downstream receptacles.

You can share a neutral between 2 GFCI receptacles.  The catch is you'll have to pigtail the neutral to the receptacles, not use the neutral from the load side of the first GFCI to feed the second.

So you should be able to do something like this...

But not like this...

You'll then be able to use the load side of each receptacle to feed other devices, like this.

white, black, red wires/GFI receptacle

white carries unused power back.
Black n Red carry power in (to power your crap)
But be careful ( if black wire is attached to a breaker at the electrical panel that is labeled an even number and the Red is attached to an odd number (hard to notice stamped numbering on cover beside breakers) Odd to odd OK     Odd to even Not ok = 240 boom!
So if Black X  and red Y then proceed with:
black to Line holes on gfi (crap hooked up to Load)
Red wire dont hook up, twist together to pass to next location. Next location hook red to LINE on gfi and dont connect black.
just don't land black and red on same location, red gfi = microwave  black gfi = fridge red gfi = blender black gfi = coffee maker
White wire should go directly to each gfi without detour. don't use white from load or line off gfi but twist a bunch so 1 white hits black gfi 1 one white hits red gfi 2, back gfi 2, red gfi 2 ....etc.

regular non-gfi rules

you can share the white wire coming from any receptacle with the same color as long as the same colored wire and it's brother white wire are hooked up to a known even or odd label (stamped next to breakers) odd to even cross 120+120=240 even to even 120+120=0 since its the same Phase (odds are phase 1 separated from power on phase 2 evens) odds are all virtually the same 120 evens are virtually common with each other at 120. red and black make 240, red and red make 120 did i miss anything?


what is the woodworking technique used to build this piece? I'm interested in building a side table similar to the one shown in this link. The woodwork technique looks complicated for an inexperienced builder (like me). How was this piece built?

This is a box joint. Some might call it a finger joint. Here I've cut out a small piece of one of the blow ups on the site.

Note the straight sides. The idea is the pieces mate together, indeed like the fingers of two hands, set to cross alternately. Without glue of course, the joint would have no strength at all. By the way, in my opinion it is a relatively poor example of a box joint. See that there are voids along those joints, that were then filled, probably with a wood filler.

A dovetail joint would have angled sides on the mating pieces, looking something like this (from Wikipedia):

You can see the difference is in the angled faces.

How was the table built? It appears as if this was done by hand work, or if a table saw was used, measurements were not done with perfect accuracy. Were I to do this, I'd use a router table, with incredibly precise bit placement, enabled by a good router fence, like an Incra-fence. A table saw would not leave flat bottoms between the fingers (UNLESS you have a good dado blade. Cheap dado blades will not do that.) The cuts CAN be done by hand work with a saw and chisels, but to do that with sufficient accuracy, it would require a fair deal of skill with those hand tools. IF you were to try this by hand, start out with some practice pieces of wood. Make a dozen joints first, only then would I trust your skill with the tools. Practice joints are a good idea anyway, with any tools.

You might check out some videos about making box joints. Youtube has lots to be found, like this one, where a table saw with a dado blade is used. Or this one, where you can see it done by hand.

Can you do this better? The fact is, the table you would get from this joint will not be terribly strong. A far better choice would be to use dovetails, which will resist torsion better using the physical shape of the dovetails, as well as glue. See that the fingers here mate along faces that can resist the torsion ONLY by means of glue. A dovetail joint is clearly stronger.

If you cannot manage a dovetail joint (I assume this is to be by by hand work, so using only saws, chisels, etc.) then I would strongly suggest that a stronger joint will be found by having MORE glue surface. The fingers in such a joint are plenty strong enough. If a box joint like this will fail due to torsion, then it will fail along those glue joints. So I'd suggest at the very least, using more glue surface here. That is, instead of having fingers that are 2 inches wide, make fingers that are about 1/2 inch side, thus creating very much more surface to be glued because there will be more fingers. Yeah, I know, it will make for more work. Do you want it to last? Really, best would still be accurately cut dovetails.

It does not appear as if any dowels were used here. BUT, to be honest, were I to build this table, I'd consider finding a way to insert small dowels, hidden inside each joint so they cannot be seen. This is easily doable. Again, the idea is to build the joint so that it resists torsion by more than simply glue surface.

Finally, as people will state, a well made glue joint is stronger than the wood it joins. HOWEVER, the glue joints I see in the picture above are not that terribly well made. There are clear voids. The mating faces are not that tightly mating. If this joint fails, which can easily happen, it will be by the fibers of those fingers tearing in shear, but it will happen along those glue joints. You can see joint failure happening in this video. Essentially the fibers right next to the glue joint will be seen to delaminate.

It's board joined together using a dovetail joint.


How can I attach a metal soap dish to tile? What is the best glue to use when you glue a metal soap dish to a tile in the bathroom.

My approach (depending on the mating surface available, shape, etc.) would be to use pure "clear" silicone along with a bit of foam tape.

Cut a small piece of foam tape to act as a temporary anchor while the silicone sets. Place it in the center of the soap dish back panel in a location that allows you to apply a bead of silicone entirely around it (to effectively seal it in).

Once the silicone is applied to the back of the dish, stick the dish to the wall and press firmly. Wipe any extra sealant from the wall and dish.

Optionally, once the silicone sets (2-4 hours should do), run a small bead around the dish to seal it further and improve appearance.

When in doubt, epoxies will bond most hard things to most hard things. As @ojait said, thoroughly clean both surfaces first.


How to fix spacing with a California corner Ugh.  So I just framed two walls that form an interior corner.  When I layed out the walls, I did the typical mark the centers on the 16's.  What I did not account for, however, was the corner. I did a California corner, which means that the drywall is not actually starting from the end of the baseplate (for one of the walls), but rather 3.5" from the end.  So how do I fix this?  It's a ~15' wall, so can I just add a stud 3.5" past the 8' mark and then have the drywallers cuss at me for having to do the adjustment to the normal spacing?

Sounds like you know the answer, and I'm sure the drywallers have seen way worse than that.

Don't worry about it, as long as you're 16"oc or less you're perfect. Most Corners, Doors & Windows are where spacing shrinks. I've got 2" spacing at the corners in my place & 4" by windows & doors. However, do worry about how you're drywall's going up. Do not accept a Horizontal install on the walls. Get Vertical in writing & on the Contract.

Do you really want some monkey-see-monkey-do idiot "pros" literally ruining your awesome new work with their absurd Horizontal butt humps, laughable floating butt "fixers" & fire code violating flexible seams & imbecilic baseboard twisting bottoms? Of course not. Again, get it in writing that the drywall will be installed Vertically & therefore right. And, Fire Them on the spot if they violate it & won't do it right...there's plenty of installers out there.


How to install Light Fixtures - no ground in the ceiling box I am trying to install a lighting fixture that I bought from Ikea.  The ceiling box has one black, one white, one blue, and one yellow lines (as in the photo below).  But, I cannot find a ground line in the box.   Can anyone explain how I can connect the ground line in the lighting fixture?  Also, I would like to use a switch to turn on and off the lighting, but I'm not sure which hot wire I should use. I guess it may be blue or yellow.

Thank you!

If you don't know, get an electrician. Your life and property are at stake.

I could make some educated guesses here but if you followed them, had a problem, and I found out about it, I'd feel bad.

There should be a bare ground wire up in the box somewhere. Connect the green wire to that.
The lamp black goes to yellow.
The lamp white goes to white.
The little double white goes to your bulb.
The black and the blue in the yellow wire nuts are just pass throughs not used for the light.


Would there be a problem installing 20A switches on a 15A circuit? I've installed 20A switches on 15A circuits before, namely on the circuit supplying my kitchen lights. It was primarily to take advantage of the side-clamp wiring available on these beefier switches instead of the curl-and-screw flavor of side-wiring, or the push-in wiring, that you normally see on 15A S/P switches.

A friend of mine says that having a switch of higher capacity than the branch circuit breaker can cause the breaker to trip. I say he's full of it; a switch is a switch, and a 20A S/P will just be beefier than a 15A. As long as it's rated for at least the amperage draw of the circuit, you're fine, IMO.

Thoughts?

On a related note, does the same apply to outlets? He may be confusing using a 20A switch and using a 20A outlet; the outlet, unlike the switch, supports plugging in appliances that will draw >15A, and if you do, that WILL trip the breaker (though as 20A outlets support plugging in parallel-bladed 15A appliances, if you KNOW the branch is 15A and don't try to plug in a T-bladed plug, you're still OK).

You are correct on both counts:

There is no problem with using a 20A switch on a 15A circuit, as the breaker will trip and protect the switch from over-current.

Using a 15A switch on a 20A circuit is potentially dangerous though: the circuit may draw up to 20A, but the switch will be overloaded at that point which may cause it to overheat/melt/start a fire.
Really this is the same as wiring: you can use larger wires (with higher current ratings) but not smaller wires

A 20A outlet is not allowed on a 15A circuit. It's not really "dangerous" since the breaker will (should) trip at 15A anyway, but it is bad to knowingly install it this way.

You must take into consideration the guage of the wire running in the wall.
If it is not rated for 20A it has the potential to catch fire.

The electrical codes are designed to STANDARDIZE for SAFETY- don't create a situation (20A plug on 15A circuit) that only YOU are aware of.

Refer to the codes, it's not a matter of opinion.


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

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

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

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


Getting single handle faucet off with no set screw I am trying to fix a leaky single handle faucet but I cannot find a set screw or really any way to get the handle off. I tried prying off and just pulling. There are no screws under or behind the lever. Any advice?

Perhaps the screw is from underneath and the assembly needs removing first.
Had a similar tap to deal with and the top slid into the body - with several o rings and was held in place by a set screw from the base. Only way was to remove it from the sink first.


Metals in pool turn water green after adding shock, what's the solution? Our pool hasn't been opened in 4 years. We are finally in the process of resurrecting it from the dead, and have spent a lot of elbow grease (and tears) to get it to the point its currently at. Last night the water was a blueish turquoise, but was still opaque and very hazy (still couldn't see to the bottom of the shallow end). I added 5 gallons of liquid chlorine ("shock") and instantly the water turned green.  I read up on it and it looks like if there is a lot of metal in the water, such as iron, chlorine has this affect.

However, all the articles/forums/info I find on this problem don't really have any good posted solutions, so I figured I'd ask:

What's the solution here? Is there a pool chemical I can buy that will help "get rid of" these metals and turn my water back to blue-ish haze?

There are several independent variables to manage in a swimming pool or hot tub:

pH balance
halogen balance
calcium hardness
total dissolved solids

Nearly everyone is aware of pH balance, but what most people don't seem to understand is that pH can swing wildly unless total alkalinity is increased sufficiently to provide an "inertial buffer" with total acid.  Then moderate changes in chlorine or bromine content do not affect the pH so much.

The other thing most people are familiar with is chlorine.  Bromine can be used instead and is just as effective at killing bacteria but with possibly less skin and eye irritation.  At my pool store, they are priced the same.  The standard home pool test kit measures both pH and "free chlorine equivalent".

Calcium should be added to soft water to prevent the water from attacking and rusting metal components of the pool and filter system.  This is a particular problem for areas such as the Pacific Northwest which has naturally soft water.  Most well-based systems will have some calcium, but if it is not adequate, some supplementation is cheap insurance for minimal maintenance.

See this for a detailed and reasonably approachable roundup of pool chemistry.  Note that everything affects everything else, so reading it twice is probably necessary to gain full insight.

In my experience, green water could be caused by either iron or copper in the water, like someone's lost jeans rivet inside the drain.  A chemical to precipitate and flocculate the metals need be done only when it is a problem.

If the history of the water is uncertain or a lot of junk has entered the pool water since it was last filled, there is no substitute for draining and refilling it.  This reduces the total chemical load to the minimum and will make it simple to balance.  To maintain that simplicity, insist that all pool users shower before entering to remove sunscreen, oils, perfumes, deodorants, etc.

Add calcium hypochlorite and a non-metal algicide.run pool pump overnight


Does new panel needs to be up to new code? I'm adding a 40A breaker to the existing panel in my condo to charge an EV (Electric vehicle). I called the city and they said that as long as I have space for the breaker that would be ok. I do have the space but I have to move a 15A breaker to the other side of the panel (Panel is challenger SL12(8-16)CGN) where the connection tab is is the opposite side. Then get the 40A and a 15A breaker. These old breakers are very expensive, $25 for the 15A and $50 for the 40A, maybe because they have the connection in the corners and not the center. The place was built in 1986 (Southern California). I can buy newer breakers and a new panel for about $100 (Square D homeline panel and breakers).

Would I need to use AFCI breaker (new NEC code) if I change the panel? That would change the price too much to do it.

Thanks

I finally called the city and talked to an inspector. My city, Diamond Bar (California) said that I did not need to have AFCIs. The GFCIs were already in the outlets in the right locations so a new panel with regular breakers was ok.

Panel is challenger

STOP! FULL STOP!

These are horribly dangerous and this needs replaced ASAP!

http://www.brubakerinc.com/home-services/challenger-electric-panel-fire/

https://inspectapedia.com/electric/Challenger_Electrical_Panels.php


How can I use a separate transformer to provide a C wire to my thermostat? Update 02/02/2019
I appreciate all the responses and help but unfortunately i must have not seen the emails stating there were responses!
I am now looking into a NEST thermostat and was curious if they too, use the same connections.
Lastly, looking for a quick recommendation on which WiFi Compatible therms are preferred by the memebers that respond!
Thanks again your knowledge is highly appreciated!
Bob

I Purchased the Honeywell WiFi Prog Thermostat to replace my Round Digital Honeywell Thermostat.
I have separate Heating and Cooling (Heating is a Weil McLain Boiler for Hot water baseboard and Hot water(no tank) and Cooling is a separate unit that was added later.)

Wires:

RC Cool
R Heat
W Heat
Y Cool
G Cool

3 wires from AC unit and 2 from Heater.

If I were to go the separate transformer route to power the thermostat, where would I land the 2 wires?

C and ???

You guys down voted the only answer that is correct and up voted one that is completely wrong!!! You CANNOT use just one wire from a transformer and expect to get it to do a thing for you. The simple answer to your question is that if you add a transformer you want to tie the lines from it to Rh and C. Most modern thermostats I know of expect to pull power between Rh and C. You do NOT want to tie Rh and Rc together since your heating and cooling are on separate transformers and you don't know if they are truly floating.

The complex answer is that you should check to see if the control board of your heating system doesn't, in fact, have a common terminal and nobody bothered to run the wires for it. If it does, it might be simpler to just pull 18/3 wire from the heater to the thermostat. Depending on the run, you can use the old two conductor wire to pull the three conductor wire through.

Bear with me on this story. I believe the above "recommendations" are wrong. Simple reason is you need to have a complete circuit as you stated. I purchased a Honeywell RTH6500WF for installation. Much to my surprise, I found out you had to have a "C" terminal. The HON adviser stated I needed to add an additional 24 volt transformer - which I did, a HON AT72D 1683. I ran it off the 120V for the furnace so that it is off when the furnace was off. Heat and wireless worked great. That was a year ago. Summer came. I turned it to AC and had nothing. The "fan on" also never worked. Using the "R" from the furnace and touched it to the "G" and the furnace fan went on. Touched "R" to "Y" and the outside condenser went on. Problem is in the HON Thermostat!

So I call HON again. Seems that they are not really focused on helping us DIYers. First adviser said he could only help me with programming. Electrical work must be done by an experienced HVAC person. I understand, but I NEED AC. So hung up and called back. Next adviser said basically the same thing. Have your HVAC person add a "C". I said I have a "C" but where does the "Load" or "R" connect. Sorry cannot help you.

So we moved to trial and error based on various videos on U-Tube. The HVAC call out fee is 250 USD so it is more than a new thermostat and it is only 24 V. So here is what I found. The "C" lead from the added 24 volt transformer goes to the "C" on the thermostat base. I then to the "Lead" or "R" from the added 24 volt transformer to the "R" block. I hooked the "R" from the furnace and hooked it to the "Rc" on the thermostat base. Nothing on the thermostat. (Hooked up the other way around gave me heat but no AC). So I said my prayers and found the jumper. I jumped "R" and "Rc" on the thermostat base and EVERYTHING WORKS. I have AC, manual over ride on the fan and heat. Good luck on getting your system up and running.


Outlet Relocation and wiring I have an outlet I am going to move up the wall.  The outlet has two cables running to it.  My question is, if I run a new straight down from my new outlet location, do I just tie together all three cables together at bottom, cap them, same color, and wire up the new outlet at top with the other end of the new cable?

I will be putting a blank face plate at the bottom where the tie in will be per code so it is accessible.  Please let me know if this is correct, I have some electrical knowledge just have not done this before and want to make sure it is acceptable.

Update:

The tabs appear to be intact, so am I safe to assume if I wire this up like I spoke of I will be ok?

Your plan sounds good, except for one thing you do have to check.

Anytime you remove an outlet, make sure you are not falling below the minimum outlets required.   In particular, a 6-foot cord from an appliance anywhere along the wall needs to be able to reach a power outlet.  It appears your old outlet is near a threshold, so if it's moving farther from the threshold, that is fine.

Looking closely at the pictures of the sides of your outlet, I'd say NO. It looks like the tabs have been broken off so that each plug of the outlet has a separate supply of power. Is one outlet switched while the other is always on?

I'd suggest running two new cables down from the new location to the old and tying one new black/white to one set of black/white in the old box, the other new black/white to the other old black white, and tying all the grounds together (as the two grounds appear to be grouped now.

In the new box, either reusing the old outlet or breaking the tab off of a new outlet, wire it up the same, with one of the new wire's black/white to one pair of screws and the other new wire to the other pair of screws. Make sure, of course, to tie the grounds together and ground the switch.

Of course, if you're looking to remove the switched control of one of the plugs or have both of them switched, then tie one new cable to the appropriate white/black pair in the old box and run that up the wall to the new location and do not break the tab off of a new outlet. Make sure you cap the unused wires in the old box.


Can I run a washer hose up and over a door? Currently my washer is on one wall next to a standing drainpipe and blocks access to an exterior door. I would like to move the washer to the exterior wall, next to the dryer, but that would require running the drain hose from one side of the room to the other.
I would like to run the hose almost completely straight up so it clears the door (the door is 7ft tall), then to turn and slowly slope down over the door, turn again (the distance between the washer and the corner of the wall is roughly 4ft), and then continue to run on a slope down the other wall (this distance is roughly 5ft) into the standing drainpipe.
I've read in a few places the water can still pump correctly as long as the hose isn't higher than 8ft, however, every video I've seen the drain is also that high and the hose doesn't then go back down. Also, would it be best to use a hose for the full length or can I use PVC pipe?
Any tips or advice would be greatly appreciated!

This may work depending on your washing machine.  You can test it by holding the hose up high (get a longer one if needed) and see if the machine drains correctly.
In my neighborhood, it's common for washing machines to pump water from basements up to the street level.  The reason is our sewer service lines are shallow.  Many homes just let that laundry water go out to the storm drains (the city allows it) so their washing machines are pumping the water up around 7 or 8 feet.  In my house, we use the sewer for laundry, but the way it's plumbed, the drain is nearly that high.  It works fine.

No, this will not work.  The drain system in a washer is designed to work with a pipe that is about 4' above the floor.  This is why they come with a drain hose that will only fit in a drain about that height off the floor.
If you try to make it drain higher up, which is what you are doing, the pump will not be able to push the water that far or, if it is able to, it will be overloaded since it wasn't designed for that purpose.
Let me suggest two options:

Move the washer to the area near the pipe.
Move the drain pipe to the new location near the washer.

Failing that, the only solution I can think of would be a drain tank next to the washer with a pump that has the capability of draining as you have drawn.  But that solution seems like it could be a recipe for disaster over time.
The only exception to this would be if the specification for your particular model of washer says that a lift of 7' is acceptable.  But this is going to be the exception not the rule.
EDIT:
You noted in the comments that the manual for the washer says 96".  So yes, your plan will work.  I'd use PVC pipe but a hose should work as well.


What is this roof constructed from? I am trying to answer questions about the construction of a roof and was wondering if it is possible to tell from the picture attached, and if so what the construction is?

EDIT: The roof is difficult to access however I have one additional picture from a slightly different angle which may or may not help. The house was originally built around 1890 (although I am guessing the roof has been reconstructed since then).

It looks like it could be a foam roofing material to me. That's a relatively new development though, as in less than 20 years old. It's used a lot on older buildings however because it's just sprayed on as a liquid that expands and foams up to get into all of the crevices in old tar paper and gravel or rolled roofs, without having to remove the old roofing. It also adds quite a bit of thermal insulation, typically lacking in old roofs and buildings. I've heard that now 90% of buildings in Arizona are getting foam roofing done now.

I see what looks like gravel. If it is it is probably a hot mopped asphalt roof that has been painted with a sealer like snow coat or another sealing paint like solar flex , these are thick and many times white or silver in color. . After another look I see wrinkles around the sky light so it could be a membrane roof that someone has coated to fix a leak. Those would be my guesses a clearer close up photo would be helpful but the wide angle was not a waste.+


Safety of "Safe" Solvents I put off stripping the paint of my interior trim until the winter, since there were so many more pleasant outdoor tasks during the warmer months. Now that it's time to fish or cut bait, I'm thinking about ventilation.
The paint I am trying to remove seems to be latex, just a coat or two, and not terribly ancient. (I'm very confident it's not lead-based). I started out (over the summer) using denatured alcohol as a stripper, but it was pretty slow going, lots of scraping, so I recently picked up some multi strip, which has dibasic esters, ethoxyproprionate, and benzyl alcohol as active ingredients. Not as dangerous as methylene chloride, but not exactly non-toxic either.
If I don't want to open my windows in January in Chicago, should I just put this project off until spring? Or will I be fine with the natural ventilation of my forced air system? The effected area will be in just two rooms--living room and dining room.

If you're trying to just remove latex paint, it might be better to try something more targeted at latex paint.  That usually means less chemicals in the cocktail involved.
There's a product called Krud Kutter, Latex Pain Remover that contains Acetone, and something called Dipropylene Glycol n-Propyl Ether.  Googling the latter indicates there's some decent evidence from valid sources like NIH that this stuff is relatively low toxicity.
https://pubmed.ncbi.nlm.nih.gov/15705495/
In general, I'd choose a more targeted stripper with the least toxic substances you can find than a general one that'll take off everything.
It seems strippers are getting quite a bit less toxic than "the bad old days" of methylene chloride.  I'd still be cautious of this stuff, since stripppers are still likely the nastiest chemicals most consumers experience.
There's other alternatives out their, like infra-red heaters (different from a heat gun).  Since you say there's no lead, this may present a completely non-toxic way to strip the latex.  I haven't used them myself, but I do recall a friend having good luck with them.

I would rather have posted this as a comment, but pics don't work in comments so I'm posting this as an answer.   Also while product recommendations are frowned upon here, I'll bend the rules a bit and post this.  I've had great luck with this product. It's pretty non-toxic, actually smells like oranges! And works pretty well. You have to have patience, it's not nearly as fast as a harsh chemical stripper and you may have to apply twice so as not to let it dry out. You'll still want to wear gloves and follow labelled directions,   But it's pretty environmentally friendly, easy to wash brushes and even the work product in plain water.


Flooring covered the ac vent Well I can't believe I did it . I put 1/4 Plywood down as a underlayment for stick down tile.i just got finished laying the tile and my son says daddy were is the a.c. vent I looked I said omg . Now what do I do the floor is done.. It's a trailer so what do I do go under the trailer? Wow

You should be able to gently tap the area close to where the hole is and listen for the hollow sound that a thin layer of plywood over a void would make.
Then using a 1/8 drill bit probe the area to locate the center and cut out a section large enough to give you a look inside. After that gently cut away the rest to the edges of the vent hole.

Find the other side, remove and drill through then make the hole and fit a new cover.

Or consider re-locating the vent if possible.


How do I disinfect a shopvac after possible contamination with hantavirus and other rodent diseases? A family member accidentaly vacuumed up some mouse droppings, and I was wondering what I should do with the vacuum to prevent the spreading of Hanta virus and similar nasties. It's a shop vacuum with a HEPA filter, and I have already changed the dust bag and the normal air filter. Should I also change the HEPA filter, or is that more than what's needed?

From the Illinois Department of Public Health

  The hantavirus is destroyed by detergents and readily available
  disinfectants such as diluted household bleach or products containing
  phenol (e.g., Lysol®). Choose an agent that is compatible with the
  item, object or area to be cleaned and disinfected.

I would change all filters, bags etc, clean out all dust that you can, and spray in an amount of liquid disinfectant with the vac running so it dissipates through the system, BEFORE fitting the new filters/bag.

(although you dont specify if this is a vac capable of handling liquids, a little spray disinfectant is unlikely to cause any damage)


Is it acceptable to splice a circuit in two opposite directions for outdoor recepts/lighting? Per the 2011 NEC, is it acceptable to...

Splice a circuit (using a junction box indoors) as long as I leave it exposed, use the correct wire connectors, and have it covered?
Use this run one side of the spliced wire to a pair of GFCI outlets at the base of my house(outside), and the other to a switch (inside) and then to a flood light (outside)?

So can I splice and can I have outdoor receptacles on same circuit as outdoor light?

Also, If anyone knows what section either of these are covered in the 2011 NEC and could tell me that would be great too!

We can't post what is not there. There is nothing prohibiting this and as Tester states, quite a bit of chapters 1 thru 3 apply in general, with spots in 4.
The NEC is NOT written in a way that you can simply look up a specific job you are doing. It can be very general and very broad, yet also specific on certain things.

I realize this question is 3 months old and the project likely done by now, but what is being proposed in the original post is fine.

The wiring code may also be locally governed.  However, I have lived in houses that have outside outlets on the same circuit with inside lights and outlets. This has always made me mildly uncomfortable, because of lightning strike issues, so I have modified that sort of wiring where I can do it without major rewiring; especially when expensive electronics are involved.


Kitchenette vs. kitchen electrical circuits I am living in a mother-in-law suite in the lower level of a 2003 home.   I just had a 6ft. kitchenette installed.  I will use a small fridge, a toaster oven, and a coffee pot.   The electrician installed one circuit that covers 3 wall plugs, only one of which (on top of counter, not fridge) has test/reset buttons (not sure what those are called).   Is this single circuit installation up to code?  Kitchens require 2 circuits, but what about a small kitchenette?

It called a Gfi outlet as long as the gfi is in the first outlet in the line from breaker it will trip before it gets to breaker box even if the last outlet shorts out our gets wet that is code in most states you are good and safe with that type of install


How can I determine the maximum wattage that I can hook up to a breaker? All of my heating is on one breaker, 240V on a double pole breaker, each marked 20A (it's a small condo). I wonder how I can determine the maximum wattage I can hook up to that breaker.

Power (Wattage) = Current x Voltage (P=I*V)

20A X 240V = 4800W

In Canada and in the United States (If i am not mistaken) total wattage is (A x W) x 80%.This goes to say, a double pole bridged 20amp breaker would be consider 40AMP. So 40AMPS x 120(Or corresponding voltage) x 80% = 4800 X .80 = 3840 would be the maximum voltage.

In order to find out how many fixtures you can put on that circuit, divide the total save load by the wattage of the fixtures.


Is connecting a 16A plug to 10A sockets for an electric water heater a problem? I had an electric water heater installed in my bathroom this morning. It uses a 16A plug but I only have 10A sockets in the bathroom (the only 16A in the apartment is high on the bedroom wall for an AC unit).

I know the hardware store sells powerstrips that can take 16A plugs, and which have 10A heads. The largest is rated to 4000w.

Would this be a safety hazard?

If yes, can I just replace the socket in the wall or do I need to get the whole damn thing rewired back to the fusebox?

ADDITIONAL INFO

The heater's plug has a built-in fuse, the kind that pop-up and can
be reset, and says 10 mA on it.
The heater offers 3 heating modes: 1000w, 1500w, and 2500w (the first 2 are individual heating elements, I assume)
I have two breakers for the bathroom. One is dedicated to one outlet, the other to the lights and another outlet. Both are rated 230/400V 50Hz 6000w IEC 60898 GB 10963

It depends on the power rating of the water heater.  From an earlier question, I see that you live in China, so your electrical supply is 220 VAC/50 Hz.  That means that the maximum power draw on a 10 A circuit is 2.2 kW (220 V * 10 A).  In general, you should draw less to allow a safety margin, if the water heater uses more than about 2 kW you should get it rewired because you'll be coming close to the maximum rating of that circuit.

Note: I'm not even considering the presence of other appliances on that bathroom circuit (lights, electric razors, electric toothbrush chargers, etc.).

Based on the additional info in the question, if you only use the 1000 W and 1500 W modes on the heater, the existing wiring should be sufficient.  If there's a way to prevent people from using the highest setting (like mounting the whole heater in a box where it can't be changed inadvertently), you should be OK.

First thing you need to check out the wire size in there. If wire size 4sq.mm or above you can change the 10 A socket to 16A.