Getting to Burial depth

[Ss95003]

I have a 6" slab poured for an patio with a covered bar area. I had a piece of conduit run to get electrical inside the cabinet area. If I were to do it over I would have them dig a 18" trench but they didn't and I can't change that now.

So I have a piece of conduit at 6" what is the best way to get to 18" if I use two 90s I don't think I will be able to pull the wire, and would that have to be under the slab anyways? do I need to do 1 90 facing down and and just go to 24" direct burial?

 

[sberry]

What type of circuit is this? Single 120V and where does it originate from?

 

[Ss95003]

Yes, one 20amp 120V line that will originate from the breaker box.
Go from slab to side of house in attic to the breaker box. using UF wire.

 

[sberry]

If you gfci before it leaves the house it can go to 12 inches.

 

[Ss95003]

unfortunately the GFCI will be at first outlet.
So is my best code compliant option to just put a 90 on it and dig to 24"?
Does the 90 need to be all the way under the slab?
Can I just do 1 with the end open and wire running to bottom of trench or do I need to do 2 90s?

 

[tyme2par4]

I believe code allows you to protect the conduit with a couple inches of concrete if you can't reach the required depth. Although that may be more work than just digging.

 

[mm08822]

If you have pvc conduit under the 6" slab then it is ok as is with that covering.

If the conduit needs to extend past the concrete, then it needs to go down to 18" min soil cover. You could offset it down to the 18" with two 45 bends and with whatever length needed in between to get the required depth.

 

[Falcon67]

The way I read it, since mine was not going across a driveway, just the yard - was 12" with a concrete covering. So I put it down 12", ripped open a couple sacks of Quikrete, poured it in the ditch, watered it, filled in said ditch.

 

[mm08822]

The way I read it, since mine was not going across a driveway, just the yard - was 12" with a concrete covering. So I put it down 12", ripped open a couple sacks of Quikrete, poured it in the ditch, watered it, filled in said ditch.

If there is 4" or more of concrete covering and no vehicular traffic, it is 4" depth of conduit.

Otherwise, a 2" concrete covering requires 12" depth of conduit.

 

[ard]

"Getting to Burial Depth"

I was NOT thinking electrical as I opened this thread....

 

[Lotek]

"Getting to Burial Depth"

I was NOT thinking electrical as I opened this thread....

Same here...

 

[wyliesdiesels]

I have a 6" slab poured for an patio with a covered bar area. I had a piece of conduit run to get electrical inside the cabinet area. If I were to do it over I would have them dig a 18" trench but they didn't and I can't change that now.

So I have a piece of conduit at 6" what is the best way to get to 18" if I use two 90s I don't think I will be able to pull the wire, and would that have to be under the slab anyways? do I need to do 1 90 facing down and and just go to 24" direct burial?

4" depth under 4" thick concrete is code. so they did what was required.

MM's idea with 2 45* sweeps is the best idea. shouldnt be hard to pull with THWN wire. UF-B might be a pain in the but. I would use individual conductors and run pipe all the way to the panel.

The way I read it, since mine was not going across a driveway, just the yard - was 12" with a concrete covering. So I put it down 12", ripped open a couple sacks of Quikrete, poured it in the ditch, watered it, filled in said ditch.

mm answered you just posting the burial table for reference

 

[ard]

Why am I not getting op? Or it took a while...

Is he now looking to complete the conduit that is now in open soil, only 6 inches below grade? VSS a stub at the edge of the slab, 6" down? Not disturbing anything alread done??

Is this 1/2 or 3/4?

You might excavate under the stub, glue on a 10 ft piece (let the glue cure...well) and just push it into a sweeping offset. Might get to say 12 inches by the point it exits from under the slab. There will be a distance where that conduit is still not 18 deep.....Toss a bag of redimix to give you a 2" protective layers until you are deep enough. If code bothers you here...

Little conduit can be very flexible. I'm thinking within a few feet you will be under 18 inches.

 

[mm08822]

Should post table in the stickies.