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Conduit through sill plate under joists?

dukes909

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Dec 15, 2008
Messages
62
A while back I posted this thread about running conduit in my basement. I haven't made any progress!..LOL..hey, life happens!

I have 3 big I-beams I have to go around (actually under) to get from one side of the basement to the other. On top of these I-beams however is a 2x8, what I will call a sill plate that the floor joists sit on. Notice in these new pictures that the existing ceiling lines up exactly (or thereabouts) with the sill plates.. If I could drill straight holes through these 2x8 I would not have to bend any conduit at all (otherwise I am looking at 12 90degree bends - 3 beams x 4 bends). Maybe you can make out the sill plates above the I-beams in these pictures (they're all painted the same color)



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Is this a bad idea? Is it allowed? Will it affect the structure of the plate? The only catch is that in one section the joists run perpendicular to the plate, so I don't know what I would actually hang the conduit from in that section. Also, if it is possible/allowed/ok how do I drill a hole straight through this 2x8??

Cheers
Dukester
 
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carap

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Aug 17, 2010
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OKC
I am certainly not a structural engineer but I don't see any reason you could not drill through the sill plate as long as you don't drill right under one of the floor joist.
 

fury9

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Mar 4, 2012
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Mchenry, IlLaHnoYs
You're fine, you could even cut a chunk out with a sawzall. Like stated above just don't do it where the joists are sitting on the 2x8
 

wssix99

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Chicago, IL
This is exactly what we did in my new house to get around a steel beam that we couldn't go under.
 
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Eriehunter

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Mar 14, 2014
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189
to drill through accurately you should use a long auger bit, oversize the hole so the conduit slips inside the hole easily with some play so it can be squared up properly. Don't drill under the joists as stated before.

it also looks like you may be able to slot the drywall on the one side and offset up into the joist space if you don't want to drill the 2x8
 

stealthmagic27

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Nov 3, 2014
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RI
Like Eriehunter said, looks like you can go right over the 2x8 in between 2 of the joists.
 

Criss

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Apr 21, 2012
Messages
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Location
Western PA
Either going over or cutting a section out of the plate is completely fine and has absolutely no structural impact. That plate is applied for the joist to rest on at the same height as the seal plate that runs the perimeter of the building, that's it, usually the joist are toe nailed @ 16" o/c so the don't bow and mess up the nailing/screwing of the sub floor. The areas you want to cut are in between and have zero effect on the surround plate material. Chop chop.
 

wssix99

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Mar 2, 2011
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5,161
Location
Chicago, IL
Cool - how did you end up drilling through the beam accurately?

I took a 1 1/2" paddle bit and went at it from both sides, meeting in the middle. I chewed up enough of a crooked and bent hole that the smaller conduit would slide through. (My work is also covered up by drywall.)

A long auger bit would be a more elegant (but more expensive) solution.
 
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