Workaround Basement Insulation for electrical work.

[John Gilmer]

Hi:

A fellow I know has a relatively new home (3 year old?) with a poured foundation. The exterior walls of the un-finished part of the basement are covered with some kind of "foil" covered product that seems to be held in place with a little glue here and there and one or two "concrete nails" with backer.

He wants to extend some outlets. While there is exposed & accessible romex in the basement it's likely the electrical inspection was done before the drywall was installed and the inspector ASSumed that the wood studs would be covered with drywall. Some were and some weren't.

Anyway, he wants to extend some outlets to areas where thee is this "foil" stuff.

What's the best approach?

1) Put the outlets and surface wiring on top of the "foil" or

2) Put the outlets and wiring under the foil and cut out access to the outlets.

In the case of #1, we would use metal boxes and metal conduit.

Or should something else be done?

Thanks

[John Grabowski]

*I'm not sure if the foil that you mentioned is for insulation purposes or is a moisture barrier of some sort. Either way my long distance opinion is to put everything on top and do not disturb the foil.

[Joe]

Seconding John's recommendation, pick up the necessary supplies of Wiremold at distributor, box store (if they have it) and do the job. Appearance-wise, it will look much neater than conduit, but with the same advantages with respect to grounding.

Joe

[clare]

Frame the wall inside the foam, install wiring in the framed wall, fill cavity with rock wool and cover with drywall.

[John Gilmer]

Huh?

Inside what "foam?" Should the new framing be put over the existing "foil" based insulaton material? Or should that stuff be taken down when the framing in installed?

[dpb]

The other poster was assuming the foil is a foil-faced solid foam insulating panel. W/O knowing for sure what it actually is and how much insulation value it has, etc., hard to say for absolute certain, but I'd concur w/ the post--simply leave what's there where it is, frame the new wall inside it and go on as conventional construction.

I certainly wouldn't use loose rockwool, however, as that implied if do add any additional insulation; whether it would be needed or even of any value depends on what the existing actually is as noted above...

BTW, if there's sufficient open floor space, quickest way to proceed is to frame wall sections flat (w/ enough clearance to stand them up and then put in place by using the second top plate mounted to the joists and nail into it rather than framing in place.

--

[Phisherman]

Sounds like the best choice.

Best not to break the barrier already there. Why create another job?

No need for metal conduit for inside-wall conduit. Plastic is much easier to work, less $ too.

For concrete/brick walls you may need surface mount conduit and boxes. The surface mount is an option on top of drywall that is already there, but in-the-wall is a much cleaner look.

[clare]

Over the existing foil-covered whatever (foam or fibreglass board is the most common I've seen).

[clare]

Nobody said anything about LOOSE rockwool. Roxul rockwool insulation bats are preferred over fiberglass for basement use because the Roxul product is not degraded by moisture and does not support mold growth.