Plastic Vapor Barrier For Concrete

This is why a vapor barrier under concrete is essential.

Plastic vapor barrier for concrete.

Vapor barriers are a way to keep moisture from getting into the concrete. 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. Very hot and humid climates may benefit from an exterior vapor barrier that keeps outside humidity from penetrating into walls. A vapor barrier is not the same as an underlayment.

It comes in a roll 14 feet by 140 feet. In temperate climates we see no advantage to placing a vapor retarder beneath a sidewalk. For most commercial applications the 15 mil thick concrete vapor barrier will be a better choice. This heavy duty plastic is commonly used under concrete slabs as a vapor barrier on top of freshly poured slabs as a curing blanket and as a temporary cover for equipment and supplies.

It will hold up better to job site traffic is more puncture resistant and a better all around product for the money. Before rolling out the underlayment be sure to sweep vacuum and remove all debris on the substructure. Thin plastic like this is often called a vapor retarder meaning it slows the vapor down but doesn t stop it. If you re in a cold climate and the subgrade soil is poorly drained a vapor barrier might be marginally useful.

For sidewalks placed directly on the subgrade soil is a sheet plastic vapor retarder useful or harmful. If you have a concrete floor that s in continuous contact with a source of moisture you re going to have problems. Always read the flooring manufacturers recommendations and instructions before installing the underlayment. A much better approach is a true vapor barrier with characteristics that conform to the requirements of astm e 1745 standard specification for water vapor retarders used in contact with soil or granular fill under concrete slabs.

How to install vapor barrier on concrete floor under laminate flooring. A vapor barrier against the concrete surface is generally recommended before wood framing or flooring materials are installed. Barricade s 6 mil plastic sheeting is a general purpose plastic film for use in a variety of construction gardening and diy applications. The concrete vapor barrier we use the most is stego wrap s 15 mil thick vapor barrier.