Vapor Barrier over existing concrete floor?

tim_60

We are installing radiant heat over our existing basement floor and will have a maxxon product poured over the tubes. Do we need to put a vapor barrier under the tubes (our basement is bone dry)? We were thinking of using steel lathe to attach the tubes with zip ties. Does this sound right?

Thanks

Mike T., Swampeast MO

When in doubt, my best advice is to request and follow manufacturer's instructions. If they suggest that a vapor barrier and/or cleavage membrane be used, then do so.

While your basement may appear bone dry with never a hint of water in liquid form, concrete is not truly vapor proof. While a "dry" basement with a heated floor is unlikely to have any problem during the heating season, things become highly unpredictable during the spring and fall which are often "wet" in much of the U.S. Summer can be a problem as well--especially if you use mechanical A/C in the basement in even a moderately humid climate. Gypsum is especially vulnerable to water problems (be it originally liquid or the result of condensation) and you want to do everything in your power to ensure that it stays bone dry regardless of atmospheric conditions.

Below-grade floors must always be considered and you will find that coverings for such floors are quite limited and even when suitable, manufacturers often change the requirements when their products are used below grade.

No manufacturer who expects to be around for any length of time wants their products to be misapplied or incorrectly installed. That's why they invest considerable resources to establish rules that by-and-large ensure the greatest possible service life of their product. Break those rules at your own risk, but don't whine if you have premature failure.

jp_2

insulation?

is there any insulation underneath?

whats your cold winter temps?

how about carpet and ceiling radiant?

Adam_29

Radon Seal

While I'm no heating specialist, this is one topic I've done plenty of research on. If your basement floor is straight concrete (not sealed or painted) there is a great product out there for you - www.radonseal.com. The problem with concrete, as others have mentioned, is that it's very porious and water can migrate through as water vapor. This product chemically reacts with the concrete and expands closing the pours. Its so good at closing the pours that it'll even block radon gas from migrating (hence its name).

Don Regan

Crete-Heat...

provides the insulation, vapor barrier and tube holder in one product. In 1" and 2" products.

Blackoakbob

Is there...

a web site for "crete-heat"? I'd like to check it out.
Best regards,

Don Regan

www.crete-heat.com