Conduit through foundation?

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Old 09-10-19, 12:18 PM
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Conduit through foundation?

Need to run a line to my swimming pool but Iím having a difficult time finding an entry point into my home. The sill plate and rim joists are blocked by my deck so I canít drill through them.

I have a basement window very similar to this example where I replaced the glass with plywood and sealed the entire thing shut with caulk. I asked my local building inspector about running the conduit through the plywood and he was less than enthusiastic.

My only other option is to drill a hole through the foundation and run the PVC through that. This might be a stupid question, but would that be a valid option? My basement is unfinished and is used for storage.
 
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09-10-19, 12:25 PM
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Conduit gets run thru block foundation walls all the time, IMO it's no big deal. Just be sure to seal the hole around the conduit.
 
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Old 09-10-19, 12:25 PM
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Conduit gets run thru block foundation walls all the time, IMO it's no big deal. Just be sure to seal the hole around the conduit.
 
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Old 09-12-19, 07:23 AM
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I asked my local building inspector about running the conduit through the plywood and he was less than enthusiastic.

If this is your preferred route, ask the inspector to point you to where the code prohibits this. Who cares about his enthusiasm, it isn't his house and his opinion doesn't mean squat! If it were mine, I'd go through the foundation wall and seal around the conduit.

I am sick of stories of inspectors trying to force their opinions on people with no basis in any code for their opinion. Just heard from a neighbor wanting to build a detached garage and the inspector won't accept plans drawn by the contractor, only wants to see plans drawn by an architect, but there is no ordinance to support using an architect at all. Seems the inspector is part of the Good Ole Boy's Club.
 
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Old 09-13-19, 11:09 AM
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He did eventually acquiesce but I reviewed my situation further and I would actually have to drill through the deck joist in order to access the window. I'd imagine that would be a big no-no in case the deck ever needed to be replaced.

I did ask him how deep the conduit needed to go and he didn't give a very clear answer. First he said 18" but then reviewed the code book and said I could 'probably' get away with 12". I found this is be odd since he is the one who will be signing-off on the work.
 
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Old 09-15-19, 07:09 PM
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Drilling through the deck joists are fine (as long as they don't affect the structural integrity of the joists). I can see the hesitancy of going through a window. In my opinion, it would be a non-workman-like manner since it's something that's never really done. Not necessarily non-code-compliant, but definitely gray area.

18" is the standard burial depth to the TOP of the cable/conduit when using PVC/EMT or UF-B cable. That is decreased to 12" if the circuit is GFI protected.
(6" is allowed if in rigid conduit or covered with concrete I believe - but is rarely done since it's a pain).
 
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Old 09-15-19, 10:25 PM
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In order to use the reduced depth of 12 inches the circuit is limited to 120 volts and a 20 amp maximum.
 
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Old 09-16-19, 10:15 PM
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This might sound like a stupid question but is it reasonable to run the conduit through the foundation completely underground? Essentially, the conduit would be completely buried from the outside. Is there any reason or concern for why this wouldnít be a good option?

With this method, is there any concern for residual water entering my basement should it enter the conduit?
 
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Old 09-17-19, 03:14 AM
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It's done that way all the time but care must be used to make sure the hole is plugged/filled and sealed to make it watertight.
 
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Old 09-17-19, 03:50 AM
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is there any concern for residual water entering my basement should it enter the conduit?
It's possible, I have a EMT conduit feeding my spa that is full of water despite being glued!
 
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Old 09-17-19, 09:25 AM
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If given the option, most electricans will run the conduit up above ground level and into the house via an LB. Best way to reduce the possibility of foundation leaks is to not make a hole in it! Plus, it's usually easier to drill through the band joist or through a stud wall than a concrete foundation.

But, other than sealing the penetration, there's no reason to not go through the foundation.
 
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Old 09-18-19, 09:28 AM
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is there any concern for residual water entering my basement should it enter the conduit?
I would have no concerns at all if it is done properly by keeping the foundation wall penetration the high point of the conduit run. I have seen a few low bid commercial office buildings where water entered the underground 4" PVC service conduits during rainy periods and water entered the building and ran out of the service conduits under a 2000 amp 480/277 Volt switchgear in the basement.
 
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