Running Wire inside basement walls

[p.k.ellis]

I have concrete block walls in my basement and instead of finishing the walls with studs and drywall, I decided to simply chip out holes in the block for the outlets and run the wire down from the top through the walls. Before I do this to any outside walls, I want to make sure that it's OK to do this. Will it affect my foundation at all to have a few holes in the block? So far it's pretty easy and looks really nice once you paint the walls and everything -- the best part is that I don't have to worry about water damage to any walls if there should ever be flooding!

[hallerb]

i have done this, you may find some blocks here and then requiring more holes, repair all well with mortar or concrete.

do realize at home resale time they will probably not count these room as finished spaces, no insulation block wall etc.

probably the major downside to your plan

[RBM]

It may make more sense to run emt or wiremold on the exterior of the block, but if you want to run cable inside the block you may need to use cable like UF or other cable for wet or damp locations

[Goedjn]

Although, if you're punching holes in the blocks anyway, you might as well dump some vermiculite in there which will add something like R2 to the walls.

[Doug Miller]

NM ("Romex"), NMC, and NMS are explicitly Code-approved "to be installed or fished in air voids in masonry block or tile walls." [2005 NEC, Art.

334.10(A)(2), (B)(2), and (C)(2) respectively]

[RBM]

You're correct, but in normally dry locations. Interior masonry walls would be dry, but perimeter walls may be damp or moist

[The Reverend Natural Light]

No drywall or panelling or anything? Just block? Uh, okay.

The only technical issue I can think of is that it's best to keep the air inside the wall separated from living space - for humidity and radon reasons, for example. Just don't decide in the future to stick drywall or panelling up against the block and call it finished.

I have a basement that was finished that way. Holes knocked in the block to recess the outlets and then tacky brown panels stuck to furring strips. The mold behind the panels was unbelievable. Damp air would draft in through the holes in the block.

But, to answer your question, the holes in the block didn't seem to affect the structure of the wall in any way. They were large enough to hold an electrical box, chipped through the thin part of the block (don't forget the inner 'rib' of the block), and no closer together than 8 feet or so.

Someday someone will have to fill them in and will curse you while they do it.

-rev

[e-mail] wrote:

[DK]

Interesting. So what is your recommendation?

A complete vapor barrier against the blocks with maybe sheet foam insulation on top of the barrier and then the drywall or paneling?

[scott21230]

I would run EMT on the outside of the walls

[jackson]

"DK" quiried

If you are going to put up finished dry wall leave a 1-2" space between the block/poured wall and your inner wall, use PT for the studs, and use the moisture proof drywall. Oh yeah, and NEVER attach anything directly to the masonry! In fact use construction adhesive for the wall bottom where it meets the concrete floor.

just my opinion