Conduit in concrete slab

[iwire]

Is the joint under consideration an expansion joint? Technically, no.

That would be one opinion

Considering it's meant to allow contraction and expansion in my opinion it is a type of expansion joint.

It is certainly more then a 'control' joint.

By the NEC, is an expansion fitting required at such a joint? Technically, no.

Really?

If it is expected to move more than 1/4" (which we have no idea if it will or will not) it is required.

Check out 352.44.

We have no idea at all what temperature changes this slab will be exposed to.

 

[Smart $]

We get them where I live. The annual temperature variation during my time living here has been over 110F, which is about double "freezing to tropical".

Welcome to Texas. Now please go home.

According to weather.com Austin TX (just picked this city as an example) reports an average annual lo/hi swing of 40? and 96?F (i.e. coldest average low, hottest average high... by month), with record extremes of -2? and 112?F. For where I live, 15? to 86? average annual swing with records of -25? and 103?F. By comparison, there is a wider temperature swing annually where I live

Regardless, I'm talking temperature swing of the concrete itself during the curing timeframe (which in and of itself is quite debatable) :grin:

 

[Smart $]

That would be one opinion

I don't know of any one person that can provide more than one... do you?

FWIW, my opinion weighs heavily upon information I have learned directly from a concrete contractor... but I guess that would only be another opinion

Considering it's meant to allow contraction and expansion in my opinion it is a type of expansion joint.

Guess we're back to one opinion here :grin:

It is certainly more then a 'control' joint.

Certainly won't get any argument from me on this one

Really?

If it is expected to move more than 1/4" (which we have no idea if it will or will not) it is required.

Check out 352.44.

We have no idea at all what temperature changes this slab will be exposed to.

...and in 352.44 it states the reason as being thermal expansion and contraction.

My contention is the joint is for hydraulic contraction... but if you can provide an authoritative reference noting otherwise, I be glad to weigh that info into my opinion :smile:

 

[danickstr]

If the concrete contractor put greased fittings, then based on his experience it would be an expansion joint. I would tend to yield to his predictions which are based on his experience and liability.

 

[electricalperson]

i just normally dig a little trench for my pvc pipe in slabs. i dont likeother trades walking on them