Concrete encased emt

[Rob1221]

Hello all, looking at section 12-1400 (EMT) it says its ok to put into concrete. Your thoughts on this, we are installing boxes in concrete wall system. 1st for me but the specs just say conduit. What have you done/used? Thanks

 

[infinity]

We install EMT in concrete quite often. There are advantages and disadvantages to using it in concrete. If it can be installed so that it won't be damaged during the pour then it's okay to use.

Welcome to the Forum.

 

[LarryFine]

Welcome to the forum.

Think of it as a concrete form that won't be removed.

 

[Rob1221]

We install EMT in concrete quite often. There are advantages and disadvantages to using it in concrete. If it can be installed so that it won't be damaged during the pour then it's okay to use.

Welcome to the Forum.

Thanks for the replys, as for the boxes could I get away with a 4x4 & mudring (duct tape it up) or do you prefer the masonry boxes

 

[infinity]

Thanks for the replys, as for the boxes could I get away with a 4x4 & mudring (duct tape it up) or do you prefer the masonry boxes

We use both types. For single gang applications with one device the masonry box is fine. If you're looking to pipe from one box to another than either a 4" or 4 11/16" box with a mud ring would be better.

 

[Another C10]

The only issue I've been aware of is the rust or deterioration at the point of where the emt leaves the encased tomb of concrete to the outside elements, typically wrapping those points with 50 mil tape or similar insulates that issue of concrete to air transition.

 

[Rob1221]

Thanks everyone, much appreciated.

 

[Joethemechanic]

rust or deterioration at the point of where the emt leaves the encased tomb of concrete

I hate that. I always come across it around here in parking lots because of the salt. Lighting, gate openers, guard shacks ect

 

[Sea Nile]

Some fittings may say they are listed for concrete, but if you read the instructions, they are only able to be in concrete if you tape them.

 

[darekelec]

Ground floor concrete slab is wet location so no emt there

 

[retirede]

Ground floor concrete slab is wet location so no emt there

I see you’re in NY. That’s a local rule, not NEC.

 

[darekelec]

Article 100
Location, Wet. Installations underground or in concrete slabs or masonry in direct contact with the earth; in loca- tions subject to saturation with water or other liquids, such as vehicle washing areas; and in unprotected locations ex- posed to weather.

 

[retirede]

Article 100
Location, Wet. Installations underground or in concrete slabs or masonry in direct contact with the earth; in loca- tions subject to saturation with water or other liquids, such as vehicle washing areas; and in unprotected locations ex- posed to weather.

But nothing in the NEC prohibits EMT in wet locations. NY has an amendment that does.

 

[darekelec]

And you are correct.

 

[Dennis Alwon]

I have used pvc in concrete walls but remember the original poster is from Canada