Do You Need a Moisture Barrier on Concrete When Laying Vinyl Flooring?

For installation of vinyl flooring you need a smooth, even surface for the underside of the flooring to achieve the best contact for adhesion. A concrete floor seems like the perfect base for a vinyl floor installation. A concrete floor with a too high moisture content can wreak havoc on a vinyl floor. A moisture barrier may or may not be needed to insure good adhesion of your vinyl floor, so do your homework to avoid problems later on down the road.

A concrete floor may need a moisture barrier before vinyl flooring can be installed.

Moist Concrete

Concrete may seem very dense, but it is actually full of small pores that will absorb water from the ground. When installing certain types of flooring -- such as sheet vinyl -- the moisture content of the concrete can be a problem. Without the proper moisture barrier, vinyl flooring acts as a moisture barrier, causing it to buckle, bubble and lift. Moisture will not damage the vinyl flooring, but will deem the adhesive that secures the vinyl to the slab almost useless. Before any type of flooring work is done, check the moisture content of the concrete before continuing. This will tell you if your concrete already has the needed protection, or if you need to add protection before installing your flooring. Concrete moisture meters can be purchased from suppliers who sell testing equipment. If you do not wish to purchase a meter, have a flooring contractor check your slab.

Moisture Barrier Under Concrete

New buildings that are built on concrete slabs may already have a moisture barrier built in to the concrete slab. Special plastic sheets are laid on the ground before concrete is poured, completely isolating the slab from the ground. This type of barrier is especially prevalent in areas with wet, swampy ground.

Adding Moisture Barrier

If you have an older home that may not have moisture barrier protection under the concrete slab, you can still add a barrier to protect your vinyl floor from bubbling. There are many products available in home centers and hardware stores in liquid form that can be used to cover and protect the concrete slab from the top.


Check with your local home center, flooring center or flooring contractor regarding what type of preparation -- if any -- is needed before applying your vinyl flooring to the slab. Local businesses that deal in flooring may already be aware of moisture issues prevalent in the area and maybe be able to quickly point you in the right direction.