Interior Vapor Barrier

So the closer your vapour barrier is to 60ng the better.

Interior vapor barrier. Not every wall does. Installing a vapor barrier on the warm interior wall of your cement brick house will prevent condensation and reduce air leakage through your walls and insulation. A continuous plastic vapor barrier prevents condensation from forming on the internal surfaces of the exterior wall.

One common set of units is g m. In existing spaces oil based paints or vapor barrier latex paints offer an effective moisture barrier. The presence of an interior vapor barrier makes drying out the cavity harder to do though.

Without poly beneath the drywall water vapor hits the drywall and diffuses through to the drier in summer indoor air. After the insulation is in place you will want to add a vapor retarder sometimes called a vapor barrier if you need one. A vapor barrier is any material used for damp proofing typically a plastic or foil sheet that resists diffusion of moisture through the wall floor ceiling or roof assemblies of buildings to prevent interstitial condensation and of packaging.

If you don t insulate your walls vapor barrier on the inside walls is ok. Vapor barriers are not typically intended to retard the migration of air. But short of that we should at least have one that allows as much drying to the interior as possible without sacrificing its winter performance.

Where it is located in an assembly and its permeability is a function of climate the characteristics of the materials that comprise the assembly and the interior conditions. For the sake of context it should be noted that polyethylene is rated at 3 4ng. Here goes the vapor barrier rules.

Vapor barriers are usually best installed on the side of the wall that experiences the hotter temperature and moister conditions. Any condensation on a properly installed continuous plastic vapor barrier will. Finally note that if using osb or plywood as the outboard windtight layer be sure to use intello plus as the interior air barrier and vapor control to ensure the assembly is 5x more diffusion tight on the inside than on the outside in winter yet allows inward drying in the summer season when air conditioning exacerbates the vapor drive inward.