Nestled in between a concrete floor and a wood floor is a vapor barrier or vapor retarder. This is material that is used for damp proofing, which is keeping moisture away from the vulnerable wood planks above. They are installed over the sub flooring and are a key part in ensuring that the wood floor looks beautiful and lasts for a long time.
When selecting a vapor retarder there are some important considerations. Most experts recommend a minimum 6 mil construction-grade polyethylene film, with perm of .13, or other impermeable material with a perm of .15 or less. A premium polymer material meeting ASTM D-1745 for concrete with higher tensile, tear and puncture resistance is highly desirable.
Without the appropriate moisture barrier, flooring material can absorb too much moisture. No matter what the flooring material is made of, moisture is the worst enemy. It can cause discoloration and staining, and can even affect any adhesive that may be holding the flooring in place. When flooring material absorbs moisture, it can cause expansion in each piece so that they no longer fit together or the edges become curled, cupped or otherwise separated. Flooring contractors should worry the most about moisture when it comes to its long-term affect on the job.
Getting the right kind of vapor retarder is critical to ensuring that the installation job will go smoothly and that the customer will be satisfied with the results. There is no other condition that can have as much affect on flooring as moisture can. It doesn’t matter whether the flooring is tile, laminate, hardwood, vinyl or something else–moisture is the one thing that can wreak havoc on a flooring job. A proper vapor retarder is the right material to ensure that moisture is kept at bay. It also ensures that the flooring contractor will not be plagued with complaints in the coming years due to too much moisture being absorbed into the wood flooring.