Moisture Barrier For Concrete Subfloor

A vapor barrier is not the same as an underlayment.

Moisture barrier for concrete subfloor.

This video describes the process of installing a moisture barrier over a concrete subfloor. Vapor barriers are a way to keep moisture from getting into the concrete. Determine your starting wall. The concrete subfloor must be sufficiently strong to safely support the flooring furniture and people in the room.

With your concrete subfloor you will need either a standard foam underlayment with a moisture barrier film or a 2in1 underlayment with moisture barrier already installed. Check the moisture level of the subflooring using a moisture meter. The barrier comes in rolls about twenty four inches wide. Usually buying the 2in1 is an easy and more economical option.

If you have a concrete floor that s in continuous contact with a source of moisture you re going to have problems. Compare the results against the manufacturer s specifications for moisture limits. This is why a vapor barrier under concrete is essential. Snap the chalk line over the top of the concrete or moisture barrier between the marks on opposite walls making a cross in the center of the room.

The presenter is using 6 mil thick poly barrier. When rolling out the moisture barrier you want to go from wall to wall and cover the entire floor. You will lay the flooring lengthwise to this wall. If you have a plywood subfloor over a concrete slab check the moisture level of both floors.

For optimal moisture control you will want to overlap the poly barrier by at least six inches. The reason is quite simple.