Vapor Barrier Under Concrete Basement Floor

By steve ragan director research and technical services the answer to this controversial question from both angles is a qualified yes vapor barriers have been associated with certain concrete slab on grade problems including curling and cracking.

Vapor barrier under concrete basement floor.

A vapor barrier should be used for all concrete floors and slabs that are going to receive an impermeable floor finish like epoxy laminate linoleum and wood or if the concrete. Any kind of persistent moisture will allow mold to get a foothold and soon ruin carpet or wood flooring. The last thing you want your customers to envision when thinking of a concrete floor is a damp cold basement slab. 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.

Always read the flooring manufacturers recommendations and instructions before installing the underlayment. Many moisture problems associated with interior concrete floors and slabs on grade can be minimized or eliminated by installing a vapor barrier under the concrete. A concrete vapor barrier is any material that prevents moisture from entering a concrete slab. Concrete garage floors vapor transmission.

For a dry mold free finished basement floor always install a vapor barrier before laying a wood subfloor or carpet pad. That way you have the extra layer of protection and don t have to worry about potential leaks. Vapor barriers are used because while fresh concrete is poured wet it s not supposed to stay that way. It needs to dry and then stay dry to avoid flooring problems.

One of the reasons those old basement floors were like that was because they had no vapor barrier beneath them leaving an easy path for water vapor from the soil to migrate into the slab assuring that the cold clammy damp feeling never went away. See what goes into waterproofing a basement too. If you ve ever had a problem with a basement floor or any concrete floor you. The 2012 international residential code states.

Before rolling out the underlayment be sure to sweep vacuum and remove all debris on the substructure. As mentioned earlier a sub slab gravel layer and vapor barrier will help keep things dry but you may not know what s under your slab. A test used by flooring contractors is to tape a square of poly to the basement floor for 24 hours and see if water droplets collect under the poly. It helps reduce mold and condensation in buildings.

Here are some of the company s and their products. 15 mil vapor barrier by americover. Is a vapor retarder barrier necessary for under the concrete slab of a garage or basement. For concrete basement floors that give off large amounts of moisture it might be worth considering installing a 6 mil vapor barrier with an underlayment that has an attached pad.