Conduit Type

[Alwayslearningelec]

So I have cast in place concrete walls but IMO the spec( attached) doesn't really specify that application. Yes I guess you could get cute and follow the concealed in walls but I do think that would be irresponsible to run EMT in poured in place concrete walls. Should be RGS.

 

[roger]

EMT would be fine. If you check the information on EMT fittings the term "concrete tight" is used and can it be achieved with tape in some cases. I have used EMT in poured walls many times.

 

[Alwayslearningelec]

EMT would be fine. If you check the information on EMT fittings the term "concrete tight" is used and can it be achieved with tape in some cases. I have used EMT in poured walls many times.

So they are asking for compression fittings. Those would be concrete tight by default or you need a special compression fitting for concrete applications?

 

[roger]

So they are asking for compression fittings. Those would be concrete tight by default or you need a special compression fitting for concrete applications?

Correct, compression fittings are (or all that I'm aware of) are concrete tight. We always used steel fittings verses cast type.

 

[infinity]

Most steel set screw EMT fittings are concrete tight when taped. In poured concrete you need to do an adequate tape job or your EMT will fill up with concrete. That's one advantage of RMC with threaded fittings, no tape.

 

[LarryFine]

Most steel set screw EMT fittings are concrete tight when taped. In poured concrete you need to do an adequate tape job or your EMT will fill up with concrete. That's one advantage of RMC with threaded fittings, no tape.

Taping is still easier than threading. Compression EMT fittings are a decent compromise.

 

[Alwayslearningelec]

Most steel set screw EMT fittings are concrete tight when taped. In poured concrete you need to do an adequate tape job or your EMT will fill up with concrete. That's one advantage of RMC with threaded fittings, no tape.

Even tape compression fitting?

 

[roger]

Even tape compression fitting?

Not compression however it's not a bad idea

 

[infinity]

When installed in poured concrete walls the EMT can be damaged during the pouring process especially if the concrete is pumped in. Care needs to be taken so that the EMT is secured tightly within the form (typically tied to rebar) to ensure that it doesn't come apart. Threaded RMC eliminates that potential problem.

 

[tom baker]

In WA EMT cannot be embedded in concrete, on or below grade due to corrosion

 

[Rick 0920]

I've installed a lot of EMT in tilt-up walls also. I agree with the duct tape over boxes and fittings. You want to run your ground screws all the way in the boxes. you can back them out later, but if you don't run them all the way in, you won't get them in later. Another trick that worked well was using a short piece of 1/4" allthread through the back of the box, drilling a 1/4" hole in the form board, then using a fender washer and hex nut to secure your masonry boxes to the form. your boxes will always be flush with the finished surface and the allthread will come out easily after the forms are removed.