# drilling ceiling joists



## subelect (Nov 25, 2007)

*Feeding an attached garage*

I am trying to get a better handle on 250.32 in preps for finishing wiring up a detached garage. The garage was built by a previous owner, no evidence of a GEC to the rebar, I will add one ground rod when I get the panel mounted. No metallic connections between the house (with the brk box supplying power) and the garage, no water pipes or struct. steel inside the garage.

I plan to bring 2 30 amp ckts (either 10/3 UF or RNC the entire length with #10s) into the garage's 8/16 QO panel. It depends what the boss wants and what the customer can afford.

With this situation, I believe that I am allowed to bond the GEC, the supply ckt's ground wire and the grounded conductor inside the detached garage's service entrance. Am I correct?

How do you remember when you can and cannot bond the grounded conductor and GEC inside detached buildings? I read my 2005 handbook several times, but I do not see an easy way to remember when you can bond and when you can't.

Thanks,
Rick


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## Jim Port (Oct 1, 2007)

For drilling have you thought about a right angle drill and a short bit? How many joists do you need to drill through? You could also try the long flexible bits, like Dversa-bit. They can get you in trouble by allowing you to drill into unseen things like wires and pipes. They can also come out in unexpected places like through the finished floor above.


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## cghelectric (Sep 22, 2009)

Is there any strapping? you can sneek under the joists if so. Alot of the houses in New England have strapping which makes that job alot easier.


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## Jim Port (Oct 1, 2007)

Rick,

IMO you would just be better off to run the 4 wire feeder and isolate the neutrals and grounds. The 08 has removed the 3 wire option for feeders to an outbuilding.


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## woodchuck2 (Sep 18, 2009)

Is there any kind of molding around the ceiling? I have pulled molding before so i could use the 1" or so of ceiling to work with. I just roto-zip the drywall out and exposed the rafters/floor joists, flexable bits can be you friend here. You can see any pipes and wires at this point too. Its not easy because of limited space and nails but i have ran circuits this way when there was no other option. Nail guard it the best you can , re-install the drywall, mud the joints and renail the molding yourself so no harm is done. Time and materials is the only way to do this and make a buck.


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## John Valdes (May 17, 2007)

Why are there two subjects, from two different OP's in the same thread? A drilling through joists thread and a sub panel thread in one.


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## user4818 (Jan 15, 2009)

I think drilling blindly through joists is a really bad idea. I say this only because I have seen first hand what can happen. 

I was working on a fire alarm project on a condo complex and it involved installed tons of MC cable in finished buildings and almost all of it was snaked in. Anyway, in the course of drilling blindly through ceiling joists one of the electricians went right through an SER cable which was the main feed for one of the dwelling units. It was a real nightmare to patch too. They ended up having to put 12X12 J-boxes in closets to splice in a new piece and of course they had to open up the ceiling to replace the cable as well. 

Anyway, I strongly discourage drilling through multiple joists if at all possible. One mistake like hitting the aforementioned plumbing pipe and your day and profit is pretty much ruined.


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## John Valdes (May 17, 2007)

subelect said:


> I am trying to get a better handle on 250.32 in preps for finishing wiring up a detached garage. The garage was built by a previous owner, no evidence of a GEC to the rebar, I will add one ground rod when I get the panel mounted. No metallic connections between the house (with the brk box supplying power) and the garage, no water pipes or struct. steel inside the garage.
> 
> I plan to bring 2 30 amp ckts (either 10/3 UF or RNC the entire length with #10s) into the garage's 8/16 QO panel. It depends what the boss wants and what the customer can afford.
> 
> ...


If you are only bringing a MWBC (sounds like what you mean) to the detached structure you require no GEC. You never bond the EGC and the neutral anywhere but at the service, and in the case of a 3 wire sub panel installation with grounding electrode that is now forbidden in 2008.

If I were doing this job it would be a 4 wire feeder, not a MWBC or two separate 30 amp circuits. JMHO.


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## oldschool (Aug 2, 2008)

Stardrill said:


> Does anybody have tips on how to drill ceiling joists through a 5" hole?
> 
> A customer wants me to add recessed lights to his existing layout in his kitchen.
> I have to drill through 5 joists to get to where he wants his next light.
> ...


if the room above is carpet you can roll the carpet back about a foot

set your circ saw to the dept of the subfloor

cut a slot a few inches wide, drill holes, wire lights, put in some 2x4's for braces, and put the sub floor back

roll carpet back and tuck it in under the baseboard

charge extra for this or tell the HO they have to patch whatever drywall you cut


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## oldschool (Aug 2, 2008)

Peter D said:


> I think drilling blindly through joists is a really bad idea. I say this only because I have seen first hand what can happen.
> 
> I was working on a fire alarm project on a condo complex and it involved installed tons of MC cable in finished buildings and almost all of it was snaked in. Anyway, in the course of drilling blindly through ceiling joists one of the electricians went right through an SER cable which was the main feed for one of the dwelling units. It was a real nightmare to patch too. They ended up having to put 12X12 J-boxes in closets to splice in a new piece and of course they had to open up the ceiling to replace the cable as well.
> 
> Anyway, I strongly discourage drilling through multiple joists if at all possible. One mistake like hitting the aforementioned plumbing pipe and your day and profit is pretty much ruined.


I was drilling thru ceiling joists once from the first floor and my diversa bit went thru the floor above,out the carpet, into the bottom of a tv, and out the front.:yes:


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## Celtic (Nov 19, 2007)

John Valdes said:


> Why are there two subjects, from two different OP's in the same thread? A drilling through joists thread and a sub panel thread in one.



...because the mods are asleep at the wheel :thumbsup:


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## te12co2w (Jun 3, 2007)

I've hit a water pipe and a wire by blind drilling. Not the same day. Ruined my day twice. I try not to do that anymore.


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## partimer31 (Jun 9, 2009)

I did it once, and the drill bit can right up though the wooden 2nd. floor.

Had a wooden floor trade person, repair the hole in the floor, customer
didn't complain at all.

Now I have a dry wall man covering my back, when it comes to sheetrock.

I ask the customer if I can open the ceiling, dry wall man does it.
I install the recess lights, dry wall man repairs ceiling to customer
satification.

A wooden ceiling same thing. Had to put in five extra lights after they
just just finish the ceiling. The guys took down all areas of the ceiling where the new recess light had to be installed, and then they put it back up. Heck it's only money. And for those without, call your local handy
man.

On one job, I think they put and took down a sheet rock ceiling three
times, because the other trades didn't get there work done fast enough on a remodeling job.

Yes I am not without faults. Even when I think there nothing in the way of my drill bit, well you know the rest....

Well I could just keep on going, but the rest of guys are thinking they have heard enough all ready.


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## McClary’s Electrical (Feb 21, 2009)

With today's modern cameras, there's no need to drill blindly, at the first joist, drill a 3" hole wtih a hole a hole saw in the middle 1/3 of the joist. This usually takes a right angle attachment. Then peek in with the camera, and drill the next with 1" flexbit. Don't drill after breaking through. Take bit out and look again with camera, you're already at the third joist. Drill that and stick fish stick in. Go to other light and repeat process, only this time, you only need to get through two. It's easy once you get going and forewarn the owner you may need to open the ceiling, just in case. But I take pride in being able to go ina finished home, and add 4-6 lights in a finished ceiling without tearing anything up. That always impresses the owners. Anybody can put them in with the ceiling down. I enjoy a challenge.


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## 220/221 (Sep 25, 2007)

> I think drilling blindly through joists is a really bad idea. I say this only because I have seen first hand what can happen.


+1 ^


Do you know how *easy* it is to cut and patch drywall?


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## TOOL_5150 (Aug 27, 2007)

220/221 said:


> +1 ^
> 
> 
> Do you know how *easy* it is to cut and patch drywall?


AND make it look like there isnt a patch? No, not easy.

~Matt


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## 220/221 (Sep 25, 2007)

> AND make it look like there isnt a patch? No, not easy.


Sure it is. It's WAY easier than electrical work. Chicks can even do it :laughing:

Some 1x2,drywall screws, masking tape, 15 minute mud, a mud pan and a couple flexible knives. A dropcloth is also a good idea.


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## bobelectric (Feb 24, 2007)

California Patch?


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## partimer31 (Jun 9, 2009)

Stardrill

"Everyone here has learn from there previous mistake". How much of a 
mistake can you afford?

Something, you need to consider, I believe you said you were adding one
more recess light. The need to drill thru ceiling joists with the plan
to use bit ext.'s tell me that your new light is more then a foot apart from the 
existing ceilling recess lights.

So have given thought about, about checking the new location for you re-
modeler recess light, before you start drilling. And if your lucky, you find
the dry wall attach to strapping, and the wooden furring straps are not
apposing you, then you should be able to slide your new wire right over the 
back side of the customer dry wall ceiling. 

Yea, I once got lucky too.


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## steelersman (Mar 15, 2009)

220/221 said:


> Some 1x2,drywall screws, masking tape, 15 minute mud, a mud pan and a couple flexible knives. A dropcloth is also a good idea.


I also patch my own holes. But instead of 1x2's I use 2x3's cause 1x2's almost always split apart when I put the screw in and I don't feel like pre-drilling them. I've never heard of 15 minute mud. I know they have 5, 20, 40 and 60 minute mud, but from my experience I'm better off using the regular joint compound. I hate mixing the quickmud.


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## steelersman (Mar 15, 2009)

mcclary's electrical said:


> With today's modern cameras, there's no need to drill blindly, at the first joist, drill a 3" hole wtih a hole a hole saw in the middle 1/3 of the joist. This usually takes a right angle attachment. Then peek in with the camera, and drill the next with 1" flexbit. Don't drill after breaking through. Take bit out and look again with camera, you're already at the third joist. Drill that and stick fish stick in. Go to other light and repeat process, only this time, you only need to get through two. It's easy once you get going and forewarn the owner you may need to open the ceiling, just in case. But I take pride in being able to go ina finished home, and add 4-6 lights in a finished ceiling without tearing anything up. That always impresses the owners. Anybody can put them in with the ceiling down. I enjoy a challenge.



But you're still drilling blindly into a joist and have the possibility of putting the pilot bit into a pipe or wire.


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## steelersman (Mar 15, 2009)

oldschool said:


> I was drilling thru ceiling joists once from the first floor and my diversa bit went thru the floor above,out the carpet, into the bottom of a tv, and out the front.:yes:


I had a similar thing happen to me not too long ago. The bit went through the floor above. But it came out under the HO's bed. It didn't damage anything, except for the carpet which won't be seen under the bed anyway. The funny thing about it is that the HO was sitting on the bed watching TV when I did this.

I will never use these bits again. I will always just cut the drywall out and drill the right way.


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## McClary’s Electrical (Feb 21, 2009)

steelersman said:


> But you're still drilling blindly into a joist and have the possibility of putting the pilot bit into a pipe or wire.


Once you get it started, take the pilot bit out. If done carefully, there can be wires on the back side, and you won't hurt them. Take your time


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## Stardrill (Mar 8, 2008)

[quote Is there any strapping? you can sneek under the joists if so. Alot of the houses in New England have strapping which makes that job alot easier.


> quote And if your lucky, you find
> the dry wall attach to strapping, and the wooden furring straps are not
> apposing you, then you should be able to slide your new wire right over the back side of the customer dry wall ceiling. quote
> 
> ...


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## BirdLaw (Sep 25, 2009)

mcclary's electrical said:


> Once you get it started, take the pilot bit out. If done carefully, there can be wires on the back side, and you won't hurt them. Take your time


Doing something carefully on the end of a 5 foot rod a couple of joist bays over while you are blind is very hard and not foolproof. You can't guarantee that the drill bit or pilot (self propelling) tip didn't nick the insulation and later cause arcing.

Spend some time with a good taper, he'll show you how to make patches quick and clean.


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## BirdLaw (Sep 25, 2009)

The only time I have seen furring strips on ceilings are in condos to isolated noise from units above and below. The furring strips are metal and act as springs to dampen sound.

What is the purpose of wooden furring strips on ceilings in houses?


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## user4818 (Jan 15, 2009)

BirdLaw said:


> What is the purpose of wooden furring strips on ceilings in houses?


To give the board hangers a nice wide piece of wood to screw into. :laughing:

That's a great question and I'm not sure of the answer. I know that it's a common practice in parts of New England and maybe some other parts of the country. I've never really known why it's done here and hardly any place else.


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## partimer31 (Jun 9, 2009)

The builder I work for, straps all ceiling joists built with conventional
timber. It gives hime a better looking ceiling sheetrock job, after all the taping is done. It also allow him to get the sheet rock level.

And his ceilings look great.


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## BirdLaw (Sep 25, 2009)

partimer31 said:


> The builder I work for, straps all ceiling joists built with conventional
> timber. It gives hime a better looking ceiling sheetrock job, after all the taping is done. It also allow him to get the sheet rock level.
> 
> And his ceilings look great.


How does strapping give it a better looking sheetrock job?

How does strapping make sheetrock more level? Unless he is using a laser and shimming the strapping to make it perfect, how is it any different than screwing the rock directly to the joists?


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## partimer31 (Jun 9, 2009)

You answer your own question.


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## BirdLaw (Sep 25, 2009)

I did some Googling. I have found that strapping a ceiling is good for the following reasons:

When wires are strung below the joists, such as in basements.
When sheetrockers suck and need more surface area to screw or nail into.
When the builder thinks the ceiling will crack from the joists moving during settling.

The last thing is the only one that would be worth it in a new house, but I really don't think there is an epidemic of cracked ceilings in the millions of houses built without strapping.

partimer31, I still think your builder is full of crap. He sounds like one of those guys who just does something because he saw it done that way before. He didn't put any thought into it himself.


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## BirdLaw (Sep 25, 2009)

partimer31 said:


> You answer your own question.


Wouldn't it be easier just to post the phrase "I don't know"?


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## partimer31 (Jun 9, 2009)

Birdlaw, post your home phone number and your 911 address, and be
happy to pass along what you think of him. :laughing:


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## BirdLaw (Sep 25, 2009)

partimer31 said:


> Birdlaw, post your home phone number and your 911 address, and be
> happy to pass along what you think of him. :laughing:


What's a 911 address?

To be honest, I'd rather you put some thought into your posts before you make them. Instead of taking some Hack's word for it and spreading misinformation, have some pride and act like someone who uses his head for a living.


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## fraydo (Mar 30, 2009)

BirdLaw said:


> What's a 911 address?


The address that appears on the dispatcher's screen when you call 911hone:


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## captkirk (Nov 21, 2007)

Well I drill with extensions all the time, but your trying to go over six feet. Thats a tough one. Its almost easier when your in a room and your adding say 6 cans. You now have three different pull points and usually have only two joist to go through at a time. 
I really think in you case unless you can do it from above or find another way to your proposed location your probably better off cutting and patching.


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## waco (Dec 10, 2007)

I worked with a good electrician who used a very long, flexible drill for some reason I can't recall. Ended up going through an upstairs bathtub rim.

Jobs in existing houses require a close and expert assessment to determine the technique(s) which have the best chances of success and blind drilling, in my view, isn't one of them, although, in my younger days, I was apt to assume there were no pipes or other vulnerable things in the path of the job. Luckily, I was usually right.

I now subcontract drywall repair and finishing which allows me to get in and get out. What was that somebody said? "Electric work is 90% technique and 10% electric."


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## nrp3 (Jan 24, 2009)

Most everything around here has strapping. Why, I don't know. Certainly helps with fishing. Saves a bunch of time instead of drilling holes through floor joists. Have to do some searching for round nail ons with back nails.


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## steelersman (Mar 15, 2009)

nrp3 said:


> Have to do some searching for round nail ons with back nails.


Do you mean the standard 8-b nail ons? And why would you need that? Just use a cut -in box for a light or a recess can for a recess light.


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## mattsilkwood (Sep 21, 2008)

I've seen ceilings furred down in basements to get past old wireing and such and ive seen it on remodels where they go over the top of th old ceiling, but I don't think I've ever seen it on new construction. Maybe some type of hurricane strapping?


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## nrp3 (Jan 24, 2009)

I like the round bakelite ones with the metal bracket on the back. I'd like to say there were some black plastic ones like that as well. The smart box rounds work good, but pricey. Which round cut ins are listed for fixture support? You may be right, maybe using cut in cans is faster. I would rather not cut drywall.


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## MDShunk (Jan 7, 2007)

mattsilkwood said:


> I've seen ceilings furred down in basements to get past old wireing and such and ive seen it on remodels where they go over the top of th old ceiling, but I don't think I've ever seen it on new construction. Maybe some type of hurricane strapping?


No, it's a northeast phenomenon. In new construction, it's a carryover from remodeling 200 year old homes where you have to strap the ceiling to get the sheetrock semi-flat and level. In an old home, the joists are often hand-hewn or at least a lot less uniform in dimension than modern lumber. With the old plaster ceiling, that was no big deal. They could make it flat with the plaster application. If you've gutted the place, you really need to strap the ceiling to prep for a decent looking drywall job.

Strapping serves no real purpose in new construction, near as I can tell. It's just tradition. In homes, they strap the ceiling with 1x3 wood lath. In commercial work, they normally strap the ceiling with hat channel. It is kinda handy when fishing wires perpendicular to the joists when doing old work. You just never really know if the ceiling is strapped or not until you make your first can hole, or whatever.


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## MDShunk (Jan 7, 2007)

nrp3 said:


> I like the round bakelite ones with the metal bracket on the back. I'd like to say there were some black plastic ones like that as well. The smart box rounds work good, but pricey. Which round cut ins are listed for fixture support? You may be right, maybe using cut in cans is faster. I would rather not cut drywall.


Yeah, when the ceiling is strapped, the brown "Union Boxes" work the best. Most other round nail-on boxes would only grab the joist by a whisker if you try to use them. The Union Boxes have the nails at the far back. If you made me guess, I'd say they were designed with this intended use in mind.


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## leland (Dec 28, 2007)

oldschool said:


> if the room above is carpet you can roll the carpet back about a foot
> 
> set your circ saw to the dept of the subfloor
> 
> ...



I've done this,works out fine. My Dads house is 200yrs old with 21" pine floors and beams.I removed the 2nd floor tongue & groove boards with a small roto Z blade and replaced them,challenging but worked out slick.

Again as stated, You sure it is not strapped off?


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