Basement Wall Insulation Vapor Barrier

Plastic specifically 6 mil polyethylene plastic is.

Basement wall insulation vapor barrier.

Polyurethane sheeting is a typical vapor barrier that contractors use to prevent moisture from penetrating the walls of a basement. Not so asphalt saturated kraft paper. We ve written several articles about basement insulation and a cost effective approach to basement insulation using foam board and fiberglass insulation since writing those articles we ve received quite a few questions about when to use a basement vapor barrier and when not to. Not every wall does.

My basement wall is insulated with a 2 inches of styrofoam on the interior and i built a 2 4 wall and added roxul insulation. If you put it on the right side where the humidity is it s not much of a vapor retarder. In any case the vapor barrier must point to the warm side. So we thought it might be a good idea to clear up some of the confusion.

Not to be confused with a vapor barrier which is placed on the warm side of the wall just in front of the insulation and behind the drywall a moisture barrier goes against the basement wall. It is for a bathroom with a tiled shower. Vapor barriers are sheets of plastic or other material placed on one side of insulation sheets. Also on the graph is the permeance of polyethylene.

A vapor barrier is also helpful to keeping a basement insulated and warm. Without a vapor barrier in place condensation inside the walls could ruin the insulation and promote the growth of harmful mold and bacteria. I live in central ontario canada. Joe says in the article plastic vapor barriers really are vapor barriers when things get wet.

When a vapor barrier is on the side of a wall where the dry air is i e outside in winter or inside in summer moisture problems can occur. Basement vapor barrier and insulation. A vapor barrier reduces the movement of water vapor by. I planned to install vapor barrier on top.

The wetter it gets the better it dries. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. For reference my basement is currently finished with concrete exterior walls then charcoal colored wrap material there seems to be an inch or two between this wrap and the exterior walls then stud framing with r12 batt insulation between the studs then a vapor barrier and finally drywall on top of the vapor barrier. This barrier is meant to keep moisture from getting to the insulation in the walls and ceilings and it is required by building codes when insulating most houses.

Is it ok to add this vapor barrier. A vapor barrier s job is to keep water vapor in humid air from diffusing through one side of a wall and finding a cool surface inside the wall.