Insulating Interior Basement Walls Vapor Barrier

A vapor barrier reduces the movement of water vapor by.

Insulating interior basement walls vapor barrier.

Whether or not you need a vapor retarder hinges on three main factors. If you have a framed wall that is adjacent to a concrete foundation wall where the vapor barrier is next to the drywall in front of the studs the fiberglass insulation gets wet and becomes a breeding ground for mold. 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. 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.

It is for a bathroom with a tiled shower. Basement vapor barrier and insulation. 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. The construction of the wall for instance is vital to the use of a vapor barrier.

Is it ok to add this vapor barrier. So we thought it might be a good idea to clear up some of the confusion. When the mold grows it will spread to. Not every wall does.

The place to control vapor migration is on the exterior of the basement wall in the form of waterproofing or damproofing. 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. 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. On the interior the best insulation to place against the concrete or block is rigid foam without any facing such as foil or plastic sheeting.

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. 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. In any case the vapor barrier must point to the warm side. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one.

The short answer is no you generally do not want a vapor barrier on the walls of a finished basement. I planned to install vapor barrier on top. Interior bathroom and kitchen walls for example are areas where there is great benefit to installing a vapor barrier. I live in central ontario canada.