RMC Conduit Burried

[DIYorBust]

I'm interested in runing burried RMC conduit to a shed from a garage. The garage is on a concrete pade that extends about 4 inches beyond the wall. Can I come up at the concrete pad, make a 90, and then use a 6 inch nipple to go through the wall, or do I have to somehow exit the ground flush with the wall?

Thank you,

DIY

 

[WorthFlorida]

Electrical work must use long sweeps designed for conduit, not 90 degree plumbing elbows. Any pipe from the ground must be SCH 80 in PVC or metal for impact protection. You can enter the structure at any height. It is far easier to use PVC sch 40 under ground and sch 80 above ground. It never rust, flexes and with good glued joints, water proofed.

https://www.familyhandyman.com/electrical/wiring/how-to-bury-underground-cable/

You can use this type of pull box as long it is approved for wet locations, usually PVC.

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[Sponsor]

 

[DIYorBust]

Electrical work must use long sweeps designed for conduit, not 90 degree plumbing elbows. Any pipe from the ground must be SCH 80 in PVC or metal for impact protection. You can enter the structure at any height. It is far easier to use PVC sch 40 under ground and sch 80 above ground. It never rust, flexes and with good glued joints, water proofed.

https://www.familyhandyman.com/electrical/wiring/how-to-bury-underground-cable/

You can use this type of pull box as long it is approved for wet locations, usually PVC.

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Thanks worth. I am using rmc conduit, what I'm trying to figure out is can I run it above grade out of the wall and over the footing for a few inches before I begin burial of the conduit. It seems like usually folks run the conduit straight down the wall and then bury it right there at the wall.

 

[WorthFlorida]

As long as you can fish wire on the turns, there are no restrictions. Straight into the ground is for convenience.

 

[Drick]

Many times you want to be able to strap the PVC or RMC to the outside of building for support which is why you generally see it run tight to the building. In your case I think what you are proposing is OK provided that it isn't somewhere a person could potentially trip on the 6" elevated portion of the RMC .

 

[DIYorBust]

Many times you want to be able to strap the PVC or RMC to the outside of building for support which is why you generally see it run tight to the building. In your case I think what you are proposing is OK provided that it isn't somewhere a person could potentially trip on the 6" elevated portion of the RMC .

Could this be concerned by running the elevated portion at grade? The obstacle to burying is that the footing extends beyond the wall about 4 inches. Half inches conduit on top of the footing doesnt seem like a trip hazard, but I guess it could be seen that way.

 

[Drick]

I think its safer at grade. The RMC will protect the wiring, its only 4 inches out from the building, and I think someone is more likely to step on it then trip on it.

 

[Kevin Crawford]

RMC is subject to rust...sooner or later. The question regarding code would be is it subject to physical damage? Car, tractor etc...or just a tripping hazard?

 

[DIYorBust]

Thanks for the advice folks. I decided to extend the conduit so that it reached a point where it could enter the garage without cross the footing. I didn't feel good about leaving a raised section(trip hazard), and bending the conduit flush with the shape of the footing did not seem easy either. I entered with an exterior box connected to a 4 inch nipple through the wall, where I transitioned from the THHN/THWN-2 to NM for the interior run. With the box installed, I added an exterior outlet, which was a nice bonus. In spite of the extra length and additional 90, I had no trouble pulling the 3 wires though. I know the RMC can be used for a ground path, but I figured it couldn't hurt to have a wired ground. The whole circuit is also on a GFI.

A lot of folks recomnded running PVC or UF-B, but I did not want to do this because I was digging the trench by hand with a shovel. Getting to 12, 18, or 24 inches is a lot more work this way, and the soil was not digging friendly. I put Kopr-Kote on the threads, and PVC wrap tape on the vertical sections. It will rust, but even if it lasts only 20-30 years, it may well outlast the shed itself. I also like that the steel conduit can easily withstand an errant shovel, or landscaping tool. It's not in an area that will see much activity though, kind of a dead space between a shed and a garage.

How did I do?