Under Concrete

[augie47]

This is from the American Concrete Institute (ACI)

and

Engineers and concrete contractors look at embedded conduit as a necessary evil. Conduit doesn't provide much in the way of strength and can often weaken the concrete if not installed correctly. Keep your embedded conduit runs at least 2 inches back (or structural engineer's requirements) from the finish to avoid "pop-outs", and allow space between the conduit and the rebar for the aggragate to flow all around both. If installing in floor slabs, install the conduit under the wire mesh.

 

[kwired]

You can ignore the TITLES, but not the text. The first paragraph of each code article tells you what the article applies to.

OK, 300.5(A) tells you what to use table 300.5 for.

 

[102 Inspector]

Could Article 300.4(F) apply since this is a shallow groove in concrete. I'm on 2008 so not sure about changes, but it says "in a groove to be covered by .......... carpeting". Seems like surrounding conduit with patching material is the same as long as conduit provides physical protection.

 

[Dennis Alwon]

Could Article 300.4(F) apply since this is a shallow groove in concrete. I'm on 2008 so not sure about changes, but it says "in a groove to be covered by .......... carpeting". Seems like surrounding conduit with patching material is the same as long as conduit provides physical protection.

I could see that applying. So it would have to be 1-1/4" below the finished concrete.

 

[Charged]

Our structural engineers don’t allow this, I believe because you can’t get a decent amount clear cover over the conduit without disturbing the rebar or wwf. I know one time I forgot to remove it from the electrical specifications and conduit was indeed installed in the second floor concrete. When it got installed the contractor did not install expansion fittings at the building control joints, I believe the inspector flagged it. That was a messy situation and we worked together to come up with a solution to fix it with as minimal rework as possible, by that time conductors had been pulled as well. I definitely learned a lot through that and appreciate anytime I can get a better understanding of how things are actually done.

 

[Hv&Lv]

This is from the American Concrete Institute (ACI)
View attachment 2559489
and

Engineers and concrete contractors look at embedded conduit as a necessary evil. Conduit doesn't provide much in the way of strength and can often weaken the concrete if not installed correctly. Keep your embedded conduit runs at least 2 inches back (or structural engineer's requirements) from the finish to avoid "pop-outs", and allow space between the conduit and the rebar for the aggragate to flow all around both. If installing in floor slabs, install the conduit under the wire mesh.

I see this one a lot..
6.3.10 — Concrete cover for pipes, conduits, and fittings shall not be less than 1-1/2 in. for concrete exposed to earth or weather, nor less than 3/4 in. for concrete not exposed to weather or in contact with ground.

So for a second story floor pour, 3/4“ is the min.
I have yet to see a plan that doesn’t spell it out in the drawings where a second floor is poured.

 

[infinity]

I see this one a lot..
6.3.10 — Concrete cover for pipes, conduits, and fittings shall not be less than 1-1/2 in. for concrete exposed to earth or weather, nor less than 3/4 in. for concrete not exposed to weather or in contact with ground.

So for a second story floor pour, 3/4“ is the min.
I have yet to see a plan that doesn’t spell it out in the drawings where a second floor is poured.

That doesn't say whether or not that is a poured concrete structure or concrete over a steel structure.

 

[romex jockey]

Is there a burial depth for conduit in concrete that is inside a building

exactly what a concrete cutter confronted me with when he sawed thru a 480 3ph feeder Den...... ~RJ~

 

[Hv&Lv]

That doesn't say whether or not that is a poured concrete structure or concrete over a steel structure.

That comes from ACI-318.
I thought that was self explanatory unless I’m missing something here..

Is the “poured concrete structure or concrete over a steel structure” exposed to weather or in contact with the ground??
If it is either, then 1-1/2”.
If it isn’t, then 3/4”

 

[kwired]

Could Article 300.4(F) apply since this is a shallow groove in concrete. I'm on 2008 so not sure about changes, but it says "in a groove to be covered by .......... carpeting". Seems like surrounding conduit with patching material is the same as long as conduit provides physical protection.

Now look at which raceways are exempted from this in exception 1.

Still need to consider if cutting the groove will fly with other codes. If it significantly weakens a structural item it probably a no go.