Conduit encased in slab

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AC\DC

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Location
Florence,Oregon,Lane
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EC
Hello, I got a call this Monday to install some short runs of 3/4 pvc for some floor outlets and island in a 4" slab. I told them I would get to it today cause I was busy this week and next week. I forgot to mention they are pouring in 3 days and everything a rush, rush.

So The hole area is ready for Pour, I don't know why I was not called out sooner since this the plumber was done 3 month ago. Either last EC bailed or Homeowner was trying to do it themself and gave up. I just ran the pipe and secured it right on top of the rebar.

Home owner tell me that Concrete guy won't like that, ill have to go under the rebar and dig a small trench. I don't have a lot of experience with concrete encased conduits, will this cause problems in the concrete ?

I told the home owner " it will pass my inspection and no were in your 1 page plan you gave me does it state that conduits in slab must be under slab".

It would not take me long to just put it in under the slab. Though with this customer he comes at you from every angle and is rush, rush, mentality is making me mad. I am bidding the rest of the house. Though if I get it and don't put my foot down I feel he will be a constant bother the whole time.
I don't need the work so it's not a big deal if I make him mad.

1:Am I wrong in encasing the Conduit.? Will it effect the slab in those shallower areas

2:Should I just please the Home owner?
 
Depends on where in the slab the rebar is located and how thick the slab will be. Ideally it should be in the center of the thickness but that rarely happens because it moves during the pour (usually down from stepping on it). By running your conduit under the rebar you eliminate any possibility of it being too close to the surface if they pull the rebar up during the pour. Your conduit shouldn't move with the rebar.

If I were you I would move it though I don't know if I would trench for it though. It's only 3/4".

Also, is this really rebar or just reinforcing wire mesh. Not that it makes any difference.

-Hal
 
For 3/4" PVC in a 4" concrete pour on grade I see no reason why it cannot be on the top of the rebar.
 
I'm generally not involved w/ construction of homes or dwellings.
But having been on many slab pours though. It does seems little odd, that there not going elevate the iron to a degree w/something, as where it's actually being in the pour, and structural iron, not below the pour.

In any case, wouldn't think they'd raise the iron, more than .75 a inch max. Your probably fine..
 
AC\DC said:
It’s rebar and is flush with the sand. I thought it would be floating.
Click to expand...

That's where it winds up or is placed by unskilled workers. Rebar or mesh should be in the center of the pour to be effective. Too many times it's just thrown in on top of the base and concrete poured on top where the reinforcing does nothing. They make blocks for the purpose of supporting the mesh or bar during the pour.

I'm wondering if they are going to try and pull it up as they pour, disturbing your conduit and your stub-ups. Dunno now. I would be tempted to fix it because I would worry that if it gets messed up you know it's going to be a PIA to fix and it's going to be on you. At least if you put it under the rebar where they shouldn't have to touch it, if it does get messed up you can blame it on them.

-Hal
 
I just did a bunch of underground on a residential 2 story .. the engineer called out for any conduit in the slab to be on top of the sand and under the grid / rebar. I’m in California if that helps


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Actually, rebar should be in the upper third of the slab thickness. That’s probably why he wants your pipe below it (the rebar). But I see no reason for the pipe to be below the slab.
 
Well I tell him, they laid the rebar incorrectly and if they decide to pull the rebar up when they pour and mess with my pipe they will pay to fix.
If they want it under the rebar pour will have to wait till I have time to fix there mistake”
 
hbiss said:
That's where it winds up or is placed by unskilled workers. Rebar or mesh should be in the center of the pour to be effective. Too many times it's just thrown in on top of the base and concrete poured on top where the reinforcing does nothing. They make blocks for the purpose of supporting the mesh or bar during the pour.

I'm wondering if they are going to try and pull it up as they pour, disturbing your conduit and your stub-ups. Dunno now. I would be tempted to fix it because I would worry that if it gets messed up you know it's going to be a PIA to fix and it's going to be on you. At least if you put it under the rebar where they shouldn't have to touch it, if it does get messed up you can blame it on them.

-Hal
Click to expand...
I learned a ton about concrete construction when me and a friend of mine built our houses with icf's. After learning all this stuff it's amazing how much hack concrete work there is out there, even most of the "pros" don't do it right. Lack of adequate reinforcement, improper location of reinforcement due to not using chairs or bolsters, inadequate insulation under slabs in heating climates, not using any water reducing admixtures and dumping way too much water in the mix, improper (usually none) curing of slabs......
 
Sounds like homeowner is trying to be the GC & isn’t doing it well. Could be very liberating to walk away from it.
 
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