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Steve Nelson
insulation over concrete foundation

what would be the best way to go. I need to insulate my basement that is damp in summer from the concrete sweating. I will be replacing the sealed windows to ventalate but I know it might still be damp. I was thinking ridgid foam then studs and fiberglass then the right sheet rock for possible damp areas.

Re: insulation over concrete foundation

I am in the process of remodeling my basement now and what I did was "hiltied" and liquid nailed straping to the walls then covered this with the rigid 1" foam then put sheet rock right over the foam. This leaves your air gap between the concrete walls and the insulation.

Re: insulation over concrete foundation

Yep, thats what www.buildingscience.com recommends for most climates. Tape the joints of the foam well. I would stop the foam 2" from the floor to allow termite inspections

Re: insulation over concrete foundation

If you have a standard block basement, you can stud the walls and have 2lb Closed Cell foam installed. This will insulate the basement, and prevent vapor from entering the area as long as you have 2"+ installed. BuildingScience.com, if you research, you will find that they are behind on information on area's.

If you use a 2x4 to stud the basement, and leave a gap behind the stud to allow the foam to cover, this will eleviate your moisture issue.

Check into the Closed Cell Spray Foam. If you use Rigid Foam Board, you will have cracks at every board.... Spray Foam you will not.

Re: insulation over concrete foundation

Where do the boards crack and what causes it?

Re: insulation over concrete foundation

I think he is talking about the seams between each foam board, not that the foam boards themselves crack.

Re: insulation over concrete foundation

correct, where the foam boards come together you will have a seam, or crack. With rigid spray foam insulation, you will no have any cracks or seams.

Re: insulation over concrete foundation

When we moved into our house the basement was semi finished so I took it for my bedroom. Boy did it get cold in the winter. Someone had put paneling up on furring strips on a concrete block wall. I removed the paneling and used the "foam board" insulation in between the furring strips and then put the paneling back. It made a HUGE difference.

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