Vapor Barrier Above Concrete Slab

Cure with waterproof sheets rather than with water or curing compounds.

Vapor barrier above concrete slab.

Choosing a vapor barrier. In general place the concrete slab directly on top of the vapor barrier with the subbase below. 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. All vapor barriers should conform to astm e 1745.

This guide says in section 2 4 1. If you are going to seal an exterior slab find a sealer that transmits water vapor breathes. 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. If it doesn t a moisture imbalance could eventually cause a flooring failure.

Concrete garage floors vapor transmission. Because extruded polystyrene insulating board will absorb little moisture the vapor barrier can be placed above or below the slab insulation. The 2012 international residential code states. However the vapor barrier under the slab must have a lower degree of permeance than the flooring or floor covering above the 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. Some builders prefer to place the vapor barrier below the insulation or even below the gravel bed because they find. 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.

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. Is a vapor retarder barrier necessary for under the concrete slab of a garage or basement. We find ourselves having to explain that the vapor retarder wasn t required or necessary for a concrete garage floor poured at or above grade. Most exterior slabs do not need a vapor barrier.

One laboratory drying study indicated that 4 in. For a vapor barrier below a concrete floor slab most choose 6 to 10 mil polyethylene. For some tips on this see sullivan s corner. If you want to make sure your slab on ground gets dry and stays dry use a vapor barrier.