Detached garage conduit leaking - under patio

[Mikej1]

Searched but thought I'd ask for current advice. Situation: 1950'S ranch with 2 car detached powered from a 20A circ. from basement main panel, nothing fancy. Garage sits about 12 feet from house (behind, side drive) and the drive also was poured to include the patio. Its a straight shot from main service back and into the garage, its just that a concrete patio is in the way. The service enters the garage up through the floating slab (no external junction box) into a cut off switch then everything is GFIC. I am getting water in the bottom of my main breaker box from this conduit and need to fix it. If I re-route around the patio that butts up against the house brick (about 12 ft x 12 ft), I would have to rewire and conduit in the basement to the other side of the patio, trench 18" deep for about 30 linear feet (have to go further than patio due to basement windows) , then rewire inside the garage back to the cut off switch. I am considering cutting the concrete because of the additional wiring, but thought I'd seek advice here. Much appreciated for the help -

 

[CGT80]

Pictures would be better. Can you access the existing conduit and use it to pull new conduit?

With such a short distance, I don't blame you for not wanting to dig a big trench or cut the concrete. Maybe others will be able to picture the situation better or have experience with a product or method to go under the concrete. To me, it sounds like the conduit must have a joint in it or it is cracked and the water is flowing inside and back to the main panel.

 

[Mikej1]

Added picture, basically, conduit comes out the back around the corner from back door, then comes up in about the middle of the left wall of the garage front. Patio goes back 8 feet on garage side.

 

[matt_i]

They make seal-off/pour-off conduit sealant compounds (and special fittings) for sealing the space inside the conduit between conductors and tube ID, where there is the danger of explosive gas mixes entering a panel where there could be arcs from moving contacts, etc.

That said, it would be better to mitigate the water issue, but the leakage doesn't hurt the wire if its made of the proper jacket. Guessing a metallic conduit was used which has rusted-thru underground. I'd go back with glued PVC although that does not guarantee a perfect leak free path.

 

[Mikej1]

Ok, I have the concrete cut. Detached garage with a 20A. I am now looking for the best materials to replace the conduit. My current run is as follows: 3/4" rmc that exits the main breaker box in the house basement through a cinder block wall 18" below grade and enters the garage through a hole in a poured floating slab. 1 90 degree bend. Can I run pvc conduit from inside the garage hole, under ground 18" and through the cinder block wall to a metal junction box inside basement attached to the current basement rmc (essentially copying the current metal conduit?? Thanks for the help.

 

[wyliesdiesels]

I dont see any pics.

I would bring the garage conduit into an exterior j box, then run a new conduit from the side of the box into the house basement. U then drill a hole in the bottom of the junction box to allow any water to drain out and not enter the conduit going into the basement that is higher up.

 

[Mikej1]

I dont see any pics.

I would bring the garage conduit into an exterior j box, then run a new conduit from the side of the box into the house basement. U then drill a hole in the bottom of the junction box to allow any water to drain out and not enter the conduit going into the basement that is higher up.

Is there a reason one wouldn't use the box inside (previously installed) and the current hole in the garage foundation that runs inside? Would seem really easy? Then run the conduit to the basement j b? Picture was not showing anything.

 

[Orionrising]

If you have it all dug up why not install a real subpanel. Should cost like 200 bucks in materials

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[wyliesdiesels]

Is there a reason one wouldn't use the box inside (previously installed) and the current hole in the garage foundation that runs inside? Would seem really easy? Then run the conduit to the basement j b? Picture was not showing anything.

Because u are having issues with water intrusion.

If u junction it like i said, then no chance of water entering inside as long as the foundation is sealed properly.

I myself would never bring conduits directly into a building below grade. Thats just asking for trouble.

 

[nsula_country]

Even glued PVC will leak due to condensate. No conduit will remain dry without positive pressure blowing thru it.

CT

 

[Mikej1]

Because u are having issues with water intrusion.

If u junction it like i said, then no chance of water entering inside as long as the foundation is sealed properly.

I myself would never bring conduits directly into a building below grade. Thats just asking for trouble.

OH, ok -you're talking about the house side, right? Actually what I plan to do -but I'm running the garage side through the floating slab the way it is now, so no jb on the garage exterior. I still haven't broken up the concrete -too nice of weather and too many bike rides!