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Help!We are acting as our own general contractor in the construction of our home, including finished basement with a heat pump air handling system.
In the June/July 2000 article on finishing basements, Rick Arnold and Mike Guertin suggest that moisture released from concrete and airborne condensation on concrete are best handled by NOT installing vapor barrier in the basement walls.They argue it is better to have walls that are permeable and permit water vapor to pass through both the concrete and the frame wall assembly.They also recommend not finishing the basement for 2 years.
We can’t wait 2 years and are proceeding to finish appromimately 60-90 days after pouring the foundation.Our Heat pump has humidity control.Our foundation walls and floor are well installed and protected by external membrane. We have 1 coat of bituminous tar on the inside of our foundation walls which is covered with strapped rigid insullation.
Our question.Should we follow this heretical suggestion of no vapor barrier in the basement?The explanation makes sense to us, but seems to run contrary to the practices and instincts of the trades people we have consulted.
Informed opinions welcome.Experience even moreso.Who do we listen to?
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Bruce: I've been around a few years in the building industry, about 40 years, and some of the new ideas and products are creating problems in the newer homes. Tyvex and some of the newer housewrapes are not letting the home breath like the alder ones. Some of the old and tested building practices will be around for some time. It's nice to have some new ideas but I think that we should look at the past a little. I would put a vapor barrier on the concrete side of the basement. It's the same principle of putting a vapor barrier under the concrete slab, code requirement. Basically, we want to keep the moisture out of the basement. Just ask yourself, why do we need to dehumidify the basement in the summer?
So Bruce, use some common sense and try to keep the moisture out. I might ad that I build in the Northern Michigan region of the country. Best Regards: Dale
*Bruce, you wrote, "We have 1 coat of bituminous tar on the inside of our foundation walls which is covered with strapped rigid insullation.."If that's true, don't you already have a vapor barrier in place? Moisture drive is from warm to cold and from damp to dry. Seems to me that the summer moisture drive is addressed by the foam insulation, which should be fairly impervious to water, and which is before your likely first condensing surface, that is, the concrete. If you put up a stud wall with a vapor barrier on the inside, what would the harm be? If your outside membrane and below-slab vapor barrier each work perfectly, no moisture should enter the wall, so no harm. But if the don't, where can the moisture dry to? Nowhere. Which I think explains Mike and Rick's contention of no vapor barriers. Basement walls are so complex.Andy
*Like Andy it seems to me you already do have a vapor barrier on the inside of your basement walls. One thing to keep in mind in all this is Fire. You want, and I think Code requires, the final surface inside the basement to be non-flammable. So, depending on what kind of insulation you have you may need to cover it.
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Help!We are acting as our own general contractor in the construction of our home, including finished basement with a heat pump air handling system.
In the June/July 2000 article on finishing basements, Rick Arnold and Mike Guertin suggest that moisture released from concrete and airborne condensation on concrete are best handled by NOT installing vapor barrier in the basement walls.They argue it is better to have walls that are permeable and permit water vapor to pass through both the concrete and the frame wall assembly.They also recommend not finishing the basement for 2 years.
We can't wait 2 years and are proceeding to finish appromimately 60-90 days after pouring the foundation.Our Heat pump has humidity control.Our foundation walls and floor are well installed and protected by external membrane. We have 1 coat of bituminous tar on the inside of our foundation walls which is covered with strapped rigid insullation.
Our question.Should we follow this heretical suggestion of no vapor barrier in the basement?The explanation makes sense to us, but seems to run contrary to the practices and instincts of the trades people we have consulted.
Informed opinions welcome.Experience even moreso.Who do we listen to?