PVC under slab = wet location?

[wirebender]

They used "or" between the 3 items and no comma after masonry so I suppose that makes them separate.

Not necessarily.

Now I am seeing underground as one thing and concrete slabs/masonry as another beacause they say in concrete slabs or masonry, not in concrete slabs or in masonry.

That's the way I see it.

Really? I wouldn't have thought that. If that's the case, case closed.

I realize that common sense has nothing to do with the code but even the NEC wouldn't consider something a wet location which is inherently moisture free.

 

[wirebender]

Let's try it again



I do not see how a vapor barrier changes this definition esp. since the vapor barrier is usually above the stone and the pipe is in or under the stone. Even if the vapor barrier were lower I don't believe the definition will help out. IMO

When we do installs like in the OP, we run the PVC on top of the plastic. That puts it in a concrete slab that is not in direct contact with the earth.

This is the same as the rules concerning CEEs.

 

[Dennis Alwon]

When we do installs like in the OP, we run the PVC on top of the plastic. That puts it in a concrete slab that is not in direct contact with the earth.

This is the same as the rules concerning CEEs.

I still don't see how that changes the def. of wet location. The slab is on grade the vapor barrier is just there also. I don't know the intent or agree with it but that is the way it reads, IMO.

 

[R Bob]

Maybe it's considered a wet location because of condensation as a result of the temperature diferential between the areas above and below the slab.:-?

Whenever I have seen conduit placed in a slab on grade the conduit is bone dry when it is installed. Go back some time later to pull wire and there is moisture in the conduit. Happens darn near 100% of the time. Every run of pipe can't possibly be allowing moisture in due to leaking fittings and breaks. Don't be standing at the receiving end when the line is blown!

Have also frequently noticed this when doing service calls.

Any thoughts?

I'm bracing myself for the onslaught.

 

[Dennis Alwon]

Maybe it's considered a wet location because of condensation as a result of the temperature diferential between the areas above and below the slab.:-?

I agree it is usually condensation.

 

[benaround]

Dennis,

I don't see ' concrete in direct contact with the earth '. I see

1 underground (or)

2 in concrete slabs (or)

3 masonary in direct contact with the earth.

 

[Dennis Alwon]

Dennis,

I don't see ' concrete in direct contact with the earth '. I see

1 underground (or)

2 in concrete slabs (or)

3 masonary in direct contact with the earth.

I'm with you on the first one but not the second. I believe there would be a comma before the or if that were the case. Actually I think it should read like this.

Installations underground, or in concrete slabs or masonry in direct contact with the earth.

If it was meant your way I believe it would be written " Installations underground, in concrete slabs, or in masonry in direct contact with the earth.

All I know is water will be in that conduit and it isn't worth the fight to prove it won't be.\

Where Charlie B when we need him.

 

[benaround]

Dennis,

In the Definitions section, they don't use any commas at all. It's just 'or'

that's one reason I feel the way I do. CHARLIE, WHERE ARE YOU !!

 

[Dennis Alwon]

Dennis,

In the Definitions section, they don't use any commas at all. It's just 'or'

that's one reason I feel the way I do. CHARLIE, WHERE ARE YOU !!

And I am saying they should have used a comma. I still think I'm right.

 

[Dennis Alwon]

Think of it this way-- why would it be a wet location above grade. That would mean everything above and below the slab was not wet location but the slab would be--- I don't think so.

 

[220/221]

They shoud have use commas or the word "in" masonry.

 

[benaround]

Dennis, I think you are right too, but charlies' rule, it says what it says,

I think it could say two things. A bit of the proper punctuation is in order here.

I'm done.

no i'm not, a concrete slab above grade is really a concrete deck, does, that, make, any, more, sense,?!!

 

[220/221]

a concrete slab above grade is really a concrete deck, does, that, make, any, more, sense,?!!

So is a deck a wet location or were you just speculating earlier?

I'm trying to learn so please signify if it's an opinion so I don't get confused.

 

[Dennis Alwon]

a concrete slab above grade is really a concrete deck, does, that, make, any, more, sense,?!!

I am not sure what your point is here. Yes it is a concrete deck but if it is surrounded by dry location areas then the deck is dry.

 

[mikeames]

When we talk about a device and grounding the code says that the device can be grounded if "its in direct contact" with a metal grounded box. That does not mean its ok to put a plastic barrier between the device and the box. If it direct contact means "nothing comes between" when grounding then its should also mean the same when talking about concrete and earth. Its should be consistent.

 

[benaround]

So is a deck a wet location or were you just speculating earlier?

I'm trying to learn so please signify if it's an opinion so I don't get confused.

speculating, but I haven't speculated in a long time, I'm trying to learn also.

Dennis, my point was a deck is not a slab, so dry location,I thought it was

but the more I read the definition, I thought the words said different.

220/221, I'll keep my speculating to a minimum to avoid confusion in the future.

 

[Dennis Alwon]

When we talk about a device and grounding the code says that the device can be grounded if "its in direct contact" with a metal grounded box. That does not mean its ok to put a plastic barrier between the device and the box. If it direct contact means "nothing comes between" when grounding then its should also mean the same when talking about concrete and earth. Its should be consistent.

So if there is stone on the earth then the slab is not in contact with the earth???

Can you insure that the vapor barrier will not get punctured and is a perfect seal?

I don't see the big deal. Run a piece of UF and be done with it. Sure I think it is bogus. I have seen NM cable used in a direct burial situation and it lasted for over 20 years till we dug it up.

That does not mena I will install nm underground or in the PVC for that matter.

 

[mikeames]

So if there is stone on the earth then the slab is not in contact with the earth???

No, stone is part of earth.

Can you insure that the vapor barrier will not get punctured and is a perfect seal?

Nope, no more than I can insure the integrity of wire insulation wont get damaged when pulled. I can do the best I can. [/QUOTE]

I don't see the big deal. Run a piece of UF and be done with it. Sure I think it is bogus. I have seen NM cable used in a direct burial situation and it lasted for over 20 years till we dug it up.

I am sure we all feel this way but this is the way all debates are.