Can I run sub-panel conduit over cement into dirt?

[remagenman]

Hello folks, figured I would just run a sub-panel at shed, which is about 30 feet from main panel in garage.

I have a 2 1/2 foot cement pad on the outside of where the garage panel is located so I would have to bridge this cement pad with conduit where the 6AWG cable will run.

So it will be conduit coming out behind panel to outside of house, going down 3 feet to cement pad, bridging the cement with conduit and into dirt buried 18 inches in conduit to the shed.

Basically, can I bridge the cement pad instead of having to break it, is this a problem?

Thanks.

 

[Red 17]

I wouldn't do it that way even if allowed. That will always be a trip hazard and vulnerable to damage. Cut the pad, trench it, cover it back up. Serving suggestion.

 

[pattenp]

What kind of cable are you using?

 

[remagenman]

Thanks, plan to use 6AWG copper wire on a 60 Amp breaker. No trip hazard as I am the only one back here and the area is already covered by a table.

 

[Jim greengo]

I'd punch a trench through the concrete then bury the pipe.
I prefer to bury it deeper than 18" myself.
It only takes a couple of swipes of somebody running through there with a skidloader to turn 18" of dirt into 6" really fast.
If you're using a machine I'd start out closer to 24-30" myself unless you know nobody is ever going to be digging through there.

 

[Supertech]

Yeah man it will work. Run 1 inch emt on the slab and strap it down with one hole straps and tapcons. Then chageover to rigid nonmetalic (grey pvc) at the edge of the concrete. Use a 1 inch ridgid coupling, 1 inch emt compression co nector and 1 inch ridgid non metallic connector for the change over.


Ofcoarse thats assuming you have a 1 inch pipe bender and can bend a couple 90s.

 

[rlitman]

I'd cut a 6" hole through the pad at the bottom of the wall, then auger horizontally from the trench to under this hole. 30" should be each to reach across and back-fill with minimal damage. Much easier than trenching through the pad.

 

[remagenman]

Yeah man it will work. Run 1 inch emt on the slab and strap it down with one hole straps and tapcons. Then chageover to rigid nonmetalic (grey pvc) at the edge of the concrete. Use a 1 inch ridgid coupling, 1 inch emt compression co nector and 1 inch ridgid non metallic connector for the change over.


Ofcoarse thats assuming you have a 1 inch pipe bender and can bend a couple 90s.

Thanks, pretty much what I had in mind but just wanted to know if it was code allowed.

 

[Supertech]

Thanks, pretty much what I had in mind but just wanted to know if it was code allowed.

Theres no rule against running pipe on a slab. People do it all the time. Just strap it well

 

[pattenp]

Thanks, plan to use 6AWG copper wire on a 60 Amp breaker. No trip hazard as I am the only one back here and the area is already covered by a table.

Again, what type cable? NM,UF, SER? Or are you using individual wires of THHN/THWN? Some types of cable are not allowed in conduit when outside.

 

[alfredeneuman]

Run 1 inch emt on the slab and strap it down with one hole straps and tapcons.

A 1/4" space is required under the conduit for drainage.

Just do what Rlitman suggests

 

[ard]

I'd cut a 6" hole through the pad at the bottom of the wall, then auger horizontally from the trench to under this hole. 30" should be each to reach across and back-fill with minimal damage. Much easier than trenching through the pad.

+1

Even a 2" hole... Chisel and sledge... You could use a hose a 3 ft of pipe w a pinhole nozzle to 'trench' the 30 inches over to the hole. Position the conducts, gle, done.

MUCH better than pipe and fittings laying on the ground- even if code allows.

 

[Supertech]

+1

Even a 2" hole... Chisel and sledge... You could use a hose a 3 ft of pipe w a pinhole nozzle to 'trench' the 30 inches over to the hole. Position the conducts, gle, done.

MUCH better than pipe and fittings laying on the ground- even if code allows.

Heck id rent a core drill before fooling with all that.

 

[rlitman]

+1

Even a 2" hole... Chisel and sledge... You could use a hose a 3 ft of pipe w a pinhole nozzle to 'trench' the 30 inches over to the hole. Position the conducts, gle, done.

MUCH better than pipe and fittings laying on the ground- even if code allows.

The last time I did this, I used a 2-3/4" auger bit in my drill that was made for planting flowers. We dug the trench up to the edge of the sidewalk, under cut a few inches, and then augered across with a drill to meet the vertical hole. It was surprisingly easy, and I've used the same method to get irrigation lines across under a few other sidewalks.

I'd do that before I do a cut and cover, because you really want to limit undercutting any sidewalk. Too much and it will settle weird later on.

Anyway, slip a piece of foam insulation over your vertical conduit (so it doesn't get trapped in the concrete), and fill in the hole in the sidewalk with some concrete, and the hole will look much better than filling in a trench wide gap.

 

[ard]

Heck id rent a core drill before fooling with all that.

Eh, so to drill 30 inches sideways at 18" down?

IMO, the drill down through the slab (or chip it out) it depends on the quality of that concrete.

 

[walta]

It can be a very local question.

Where I used to live all sheds were consider temporary building and not taxed but they were also not allowed to have foundations, electricity or plumbing plus they required to be more than 10 feet from any building to slow a fire from spreading between them.

Walta

 

[bamawildcat]

I see all the time in industry where folks put a piece of unistrut attached to the concrete, then attach the conduit to that to span concrete.