# Running EMT through joists?



## 99cents (Aug 20, 2012)

Cut it into short pieces? Run flex? Tell the GC to give you a shallow bulkhead?


----------



## splatz (May 23, 2015)

I asked about this a while ago, someone from Chicago where everything's done in conduit said you can fish 1/2" in. You oversize your holes a little, put it a little off center, and use some persuasion. I am dying to try it when I have some time to mess around but have not yet. 

I think with 2x6 framing you can oversize your hole enough to get some wiggle room while still not taking more than the rules permit out of the stud. 

I have assembled 14.5" pieces of EMT and it worked out OK. Nothing to brag about but OK. 

BTW, a drywall screw in the stud will go right through EMT, I'd use nail plates.


----------



## active1 (Dec 29, 2009)

We did it all the time in Chicagoland.
1.12 - 1.25 size hole.
Closer to the bottom makes it easier, but leave at least 2" of meat.
EMT has flex to it.
Make sure you holes line up.
Don't expect full sticks.
But 2' - 4' may be doable depending on factors.
The old homes had it done with RMC thru studs and joists.
All threaded 1/2 - 1" ridgid runs in wood framing.

Nailplates for EMT is a waist of time.
Most of the time the wood will strip, pipe dodge the screw, or screw too short.
It's only when the screw it the wrong type, have a good amount of wood in front, and a screw gun guy that wont take no for an answer.


----------



## 99cents (Aug 20, 2012)

active1 said:


> We did it all the time in Chicagoland.
> 1.12 - 1.25 size hole.
> Closer to the bottom makes it easier, but leave at least 2" of meat.
> EMT has flex to it.
> ...


3/4?


----------



## splatz (May 23, 2015)

active1 said:


> Nailplates for EMT is a waist of time.
> Most of the time the wood will strip, pipe dodge the screw, or screw too short.
> It's only when the screw it the wrong type, have a good amount of wood in front, and a screw gun guy that wont take no for an answer.


Last time I did it, for a TV over a mantle. I opened up the wall and ran 1" EMT in the 2x6 framing, pieced together. 

I left it to come back after the wall was patched to mount the TV etc. I went to fish in my junk, came to a dead stop about 3/4 through. Tried the other way, dead stop about 1/4 through. Much cursing, puzzlement, impossible! 

Pull the wall apart again. The homeowner patched the drywall himself, used way too long screws (maybe like a cheap deck screw that looked like a galvanized drywall screw) and went right through the pipe. YOU HAVE TO BE KIDDING. 

Now I use nail plate. It may waste twelve cents per stud, IDGAF.


----------



## scotch (Oct 17, 2013)

Short pieces remind me of looking at a boiler job in a basement where the guy....a pipe fitter .....had put in the hot water loop with lunch box lengths of 3/4" pipe and couplings ! I joked it would have been easier to tell his boss he's spending all the threading time , etc ....so just give him full lengths of pipe to save the company money !


----------



## telsa (May 22, 2015)

splatz said:


> Last time I did it, for a TV over a mantle. I opened up the wall and ran 1" EMT in the 2x6 framing, pieced together.
> 
> I left it to come back after the wall was patched to mount the TV etc. I went to fish in my junk, came to a dead stop about 3/4 through. Tried the other way, dead stop about 1/4 through. Much cursing, puzzlement, impossible!
> 
> ...


You don't want to hear my stories -- about long screws power-drilled into conductors.


----------



## B-Nabs (Jun 4, 2014)

Just curious 99, what's it for?


----------



## active1 (Dec 29, 2009)

splatz said:


> Last time I did it, for a TV over a mantle. I opened up the wall and ran 1" EMT in the 2x6 framing, pieced together.
> 
> I left it to come back after the wall was patched to mount the TV etc. I went to fish in my junk, came to a dead stop about 3/4 through. Tried the other way, dead stop about 1/4 through. Much cursing, puzzlement, impossible!
> 
> ...


A typical home or business could require lots of nail plates. Like I said it''s when someone gets stupid. Will a nailplate stop stupid. Maybe, maybe not. Get a continuity tester, fish tape, and find that screw. Remove and pull wire. Back charge. Goes with the territory.


----------



## MechanicalDVR (Dec 29, 2007)

telsa said:


> You don't want to hear my stories -- about long screws power-drilled into conductors.


I've seen way more 6"-9" roofing screws penetrate conduit and boxes than EMT in framing but you know it happens.


----------



## active1 (Dec 29, 2009)

99cents said:


> 3/4?


3/4" what?
RMC in wood? Yes, about 80 years ago.
3/4 EMT in wood. 1/2 is much easier because it is easier to flex, but if needed 3/4 can be done.
3/4 of wood before a screw hits the EMT on a stud the screw tends to strip in the wood. Most of the time the holes have play so it can push the conduit back 1/4 more before really hitting or off to the side at that point with 1/2" drywall your talking at a screw longer than 1.5".


----------



## MechanicalDVR (Dec 29, 2007)

active1 said:


> 3/4" what?
> RMC in wood? Yes, about 80 years ago.
> 3/4 EMT in wood. 1/2 is much easier because it is easier to flex, but if needed 3/4 can be done.
> 3/4 of wood before a screw hits the EMT on a stud the screw tends to strip in the wood. Most of the time the holes have play so it can push the conduit back 1/4 more before really hitting or off to the side at that point with 1/2" drywall your talking at a screw longer than 1.5".


1 5/8" is the most common drywall screw for 1/2" rock on wood studs, 1 1/4" for metal.


----------



## 99cents (Aug 20, 2012)

B-Nabs said:


> Just curious 99, what's it for?


I quoted a job where I need to take quite a few circuits off the main panel and move them to a sub. If I can get pipe in there it saves running a bunch of individual cables.


----------



## lightman (Oct 14, 2015)

telsa said:


> You don't want to hear my stories -- about long screws power-drilled into conductors.


It might be fun to start a thread about screws in conduit!


----------



## MechanicalDVR (Dec 29, 2007)

lightman said:


> It might be fun to start a thread about screws in conduit!


There is a reason they are called screws!


----------



## splatz (May 23, 2015)

99cents said:


> I quoted a job where I need to take quite a few circuits off the main panel and move them to a sub. If I can get pipe in there it saves running a bunch of individual cables.


There is no shame in doing it in ENT.


----------



## splatz (May 23, 2015)

splatz said:


> There is no shame in doing it in ENT.


And there will be no more arguing about the nail plates LOL


----------



## telsa (May 22, 2015)

99cents said:


> Cut it into short pieces? Run flex? Tell the GC to give you a shallow bulkhead?


This is so unusual -- so I'd just go with dinky EMT runs -- and lots of couplings -- and not slow down.

Above all, I would NOT injure the framing any more than absolutely necessary. 

No over-sized holes for me.

The real trick is to get all of your holes lined up.

Notches ruin the strength of most joists.


----------



## telsa (May 22, 2015)

splatz said:


> There is no shame in doing it in ENT.


My AHJ would have a fit... it's prohibited for power circuits hereabouts.

( Unless it's encased in concrete or slurry )


----------



## splatz (May 23, 2015)

Actually the shallow bulkhead mentioned in the first post might be the best way to go, especially if it's a long straight run along one wall. Let's say you could do what you need to do with 1" EMT. Strap the EMT to the bottom of the joists, and nail up doubled 2x4's like giant running boards along the EMT on either side. Just a little extra work to drywall and you have a nice soffit, you could put lotus lights in there, probably room for a spare conduit too, but it would probably be fishable in the future if you needed to. The more I think about it the more I like that for a basement.


----------



## 99cents (Aug 20, 2012)

With any amount of luck, there will be a beam in the vicinity that the GC can fir out to to accommodate the conduit. It would be an easy 90 and kick from the joist cavity onto the beam.


----------



## PlugsAndLights (Jan 19, 2016)

99cents said:


> I quoted a job where I need to take quite a few circuits off the main panel and move them to a sub. If I can get pipe in there it saves running a bunch of individual cables.


If you go this route, you may want to visit table 5C : ampacity 
correction for more than 3 conductors. 
P&L


----------



## active1 (Dec 29, 2009)

splatz said:


> Actually the shallow bulkhead mentioned in the first post might be the best way to go, especially if it's a long straight run along one wall. Let's say you could do what you need to do with 1" EMT. Strap the EMT to the bottom of the joists, and nail up doubled 2x4's like giant running boards along the EMT on either side. Just a little extra work to drywall and you have a nice soffit, you could put lotus lights in there, probably room for a spare conduit too, but it would probably be fishable in the future if you needed to. The more I think about it the more I like that for a basement.


Basements in Chicagoland is very common. 
That would be a good bid question about open ceiling or hardlid.
Often new construction basements were left unfinished.
If nobody cared conduits were surface mounted with j-boxes on the joists bottoms scattered. More often the GC would specify no surface mounted in much of the space. There would normally be a mechanical area to be a future soffit with HVAC, plumbing, and gas mechanicals. It would be a lot more than 1 conduit here or there. Never in my life have I seen an EC fir wood around conduit in an open cieling. Many times had to rework existing off joist bottom, had carpenders drop cieling height or build a soffit.

The 1st floor cieling is harder if you have a 2nd floor.
Can't always go up or down. Such as can light down a long hall. What are you going to do. Fir down the entire 1st floor? Or make decorative boxes connecting lights and fans?


----------

