Put Plastic Under Concrete Slab

This was verfied by some field studies conducted by concrete construction magazine.

Put plastic under concrete slab.

A concrete vapor barrier is simply a sheet of polyethylene plastic visqueen placed directly on top of the sub grade before the concrete floor or slab is poured to help keep moisture from the soil from passing up through the concrete. So yes a vapour barrier is required under a concrete slab for a class 1 building a dwelling and for class 10 eg a garage where the slab is continuous with the dwelling. Aci 302 1 guide for concrete floor and slab construction states that the minimum thickness of an effective vapor barrier is 10 mils. Why a plastic vapor barrier under concrete slab mondays withinstall the proper type of vapor barrier siouxland homesare vapor ers necessary for bats and garagesvapour barrier under concrete.

Don t worry if the concrete contractors put a few holes in the poly. Plastic under concrete floor or not. The american concrete institute states that a vapor retarder should be placed directly under a concrete slab on grade if now or in the future a low permeable membrane floor finish will be installed upon the slab. Thick concrete samples having a w c 0 50 and sealed from below required 82 days for the vapor emission rate to reach 3 0.

Thanks for the question. The rate that moisture escapes from a slab depends on the concrete w c the density of the finish the ambient conditions above the slab and the moisture below the slab. There are debates about this with varying national regional state and local regulations. Thinner plastic can t stand up to the abuse of construction.

One contractor says to put plastic under the concrete it prevents moisture from coming up into the concrete. Florprufe vapor barriers gcp lied concrete vapor barriers the pros vapor barrier under concrete slab vapour barrier concrete floor problems building concrete vapor barrier what is a. They do this for two main reasons. Vapour barriers are the black plastic that builders put under residential house slabs.