Blown-In Wall Insulation with Existing Fiberglass

[Buck Turgidson]

I have a 1961 home with 4" walls. I opened up a stud cavity and could see that there is about 1.5" or so of fiberglass with kraft paper against the sheathing. So there is about 2" of dead air space between the drywall and kraft paper.

I had a proposal from an insulation contractor to blow in cellulose to fill the area between the dryall and kraft paper. I am concerned because they'll be insulation, a vapor barrier, and then more insulation.

Will this cause a problem. Would the extra insulation be worth the trouble?

[Speedy Jim]

It can make a significant difference adding the cellulose.

You can minimize the condensation problem by painting the interior wall surfaces with vapor retarding paint.

Monitor the indoor humidity levels during winter. If you currently run a humidifier, you may be able to leave it off.

Jim

[Bob F]

The worst things that could happen are your house will rot, or you will get horrible mold growth.

Bob