Vapor Barrier Above Concrete Slab
These 10 mil and 15 mil vapor barriers are very puncture resistant and will not break down over time creating a true moisture barrier between the sub grade and.
Vapor barrier above concrete slab. Choosing a vapor barrier. Some builders prefer to place the vapor barrier below the insulation or even below the gravel bed because they find. Concrete garage floors vapor transmission. However the vapor barrier under the slab must have a lower degree of permeance than the flooring or floor covering above the slab.
For some tips on this see sullivan s corner. For a vapor barrier below a concrete floor slab most choose 6 to 10 mil polyethylene. 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. If you want to make sure your slab on ground gets dry and stays dry use a vapor barrier.
Our moistureblock is a 6 mil polyethylene film vapor barrier that is used during the installation process with floating laminate luxury vinyl planks and engineered wood floors. Most exterior slabs do not need a vapor barrier. In general place the concrete slab directly on top of the vapor barrier with the subbase below. Cure with waterproof sheets rather than with water or curing compounds.
All vapor barriers should conform to astm e 1745. If you are going to seal an exterior slab find a sealer that transmits water vapor breathes. Is a vapor retarder barrier necessary for under the concrete slab of a garage or basement. The 2012 international residential code states.
It is also possible that too much water or cement paste would be absorbed from the concrete by the sand but probably not under most circumstances. Vapor barriers come in two types 6 mil vapor barrier roll. Aci 302 1r 11 guide for concrete floor and slab construction doesn t advocate universal use of vapor barriers but does make recommendations for their proper use. If it doesn t a moisture imbalance could eventually cause a flooring failure.
Because extruded polystyrene insulating board will absorb little moisture the vapor barrier can be placed above or below the slab insulation. One laboratory drying study indicated that 4 in. 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. New generation vapor barriers made from the highest grade virgin polyolefin resins have been developed that are considered true below slab vapor barriers or concrete vapor blockers.