Vapor Barrier For Concrete Block Walls

Seam tape is used to put up vapor barriers on concrete walls.

Vapor barrier for concrete block walls.

Below grade walls and floor slabs transmit ground moisture through concrete walls or slabs. This not only insulates the walls but also keeps rising dampness in the concrete from getting into the crawlspace. How to glue a vapor barrier to a cement block wall. Concrete block wall systems are also quite common on job sites.

Whether or not you need a vapor retarder hinges on three main factors. A vapor barrier against the concrete surface is generally recommended before wood framing or flooring materials are installed. We used thermax brand available through lumberyards of polyethylene vapor barrier because it doesn t require an additional fire barrier. Attaching vapor barrier to a concrete wall can help to prevent the movement of moisture through the concrete and into the building.

After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. This wall assembly will dry from the vapor barrier inwards and will dry from the vapor barrier outwards. By nature vapor travels from areas of higher concentrations to lower. On a concrete block wall system you will find that the course of a block has a horizontal truss type or ladder type joints reinforcing it.

Cover exposed foundation walls with 1 1 2 in. 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. A vapor retarder is a material used to prevent water vapor from diffusing into the wall ceiling or floor during the cold winter. Eliminating the movement of moisture into a building reduces the likelihood of mold and other problems caused by the buildup of water.

Even if you are not using vapor barriers and are trying to attach objects to individual blocks instead of an entire wall seam tape is still a good bet for strong adherence. Not every wall does. Very hot and humid climates may benefit from an exterior vapor barrier that keeps outside humidity from penetrating into walls. Concrete block with interior frame wall cavity insulation and brick or stone veneer applicability limited to mixed humid hot humid mixed dry hot dry and marine regions should not be used in cold very cold and subarctic.

Depending on your location 6 mil vapor barrier can also be used as part of a. These blocks typically measuring eight inches high can also hold an air barrier. Of rigid moisture proof insulation. Lay a continuous layer of 1 4 inch foam gasket or similar moisture and air barrier on top of the concrete slab before applying sill plates.