Finished Basement - Ohio - Moisture and Vapor Barrier

cheddarthief

I just recently had a contractor install a bathroom in my basement. He did a great job. No problems there. Because of the design of my basement, there are block abutments that stick into the space of the basement around the perimeter. As a result, to get the walls all even, we just built the stud 2x4 walls about 6" from the concrete wall(we used PT base wood and KD studs and head boards). I know this eats up some floor space but I was told that this helps with air circulation and will cut down on moisture and mildew build up. And since this house was built in the 50's there have been instances of dampness during extreme rain conditions...no visible water though.

Now, I'm doing a bedroom, rec room, and storage room build myself. I have experience in this and I'm confident in my abilities. I'm also building the framed walls about 6" from the concrete and will insulate the framed portion of the walls since it will be a usable space. I know that Owens Corning sells insulation with a vapor barrier already on it. Is this enough or should I add the plastic vapor barrier as well? Also, don't laugh on this one but I was thinking of adding some small circulation fans to the areas behind the walls to help with any moisture if it ever occurs. The block was painted and as I said we've had moisture in the past that flaked the paint. I scraped what I could and UGL drylocked everything half way up the wall (I know it doesn't work on painted surfaces but figured it won't hurt). The best part is that the ceiling will be completely open around the basement and be free to "breathe" into the storage room which will not be finished. I had planned on putting a large dehumidifier in this room in the spring and fall and with the fans figure this will eliminate any chances of mildew/mold behind the new finished walls.

Any thoughts?

jklingel

if your new walls are insulated, as it sounds, the 6" of air space is going to minimize the effect of your insulation; convective loops. no vapor barriers in basements, and usually not anywhere else. AIR sealing is what is important. myself, i would have put rigid foam on the block wall, air sealed them, and built a 2x4 wall against that and around the concrete "abutments" (pilaster, i believe they are called), letting them stick out a bit (maybe put a decorative post on top so they look intentional???). never let air wash over batt insulation, if you can avoid it. all that said, if the tops of the walls are open to "breathe", then why insulate? i'm confused on that part. j