Air Barrier Vapor Permeable

Permeability values of materials are irrelevant in air barrier systems.

Air barrier vapor permeable.

Materials with lower perm ratings are better at stopping the movement of water vapor. Air shield lmp stops the movement of air while at the same time allowing the passage of vapor. Ccw provides three types of air barriers. I will agree that it is possible to install 6 mil polyethylene as an air barrier.

Gcp applied technologies gcp perm a barrier vps vapor permeable sheet membrane is a vapor permeable air and water barrier membrane consisting of a proprietary breathable carrier film with a specially designed adhesive. 3m air barrier with permeable backing 3015vp is a self adhered vapor permeable wind and water resistant membrane with an aggressive acrylic adhesive and a breathable film. Perm a barrier npl air and vapor barrier is a fluid applied one component membrane that cures to form a resilient monolithic fully bonded elastomeric sheet when applied to construction surfaces. Primer is not required on most construction surfaces.

They have been tested to resist air leakage astm e 2178 and astm 2357 have low vapor permeance less than 0 1 perms and are watertight. Vapor barriers are also a cold climate artifact that have diffused into other climates more from ignorance than need. If it s really low it is a vapor barrier. Air shield lmp is also a single component liquid applied vapor permeable air liquid moisture barrier.

Although 6 mil polyethylene is an excellent vapor barrier it is often a very poor air barrier. This reverse wound roll allows for longer roll lengths increasing contractor productivity. An excellent discussion about the differences between vapor barriers and air barriers can be found in quirrouette 1985. Perm a barrier npl membrane protects above grade wall assemblies against the damaging effects of air and liquid water ingress on building.

Greater than 10 perms. If the perm rating is low enough the material is a vapor retarder. Air barriers are essential for a high performing building envelope. Selecting the right air barrier for your project our knowledgeable technical sales representatives provide guidance of fluid applied sheet and vapor permeable systems a systematic approach appropriate for an area s climatic conditions and development of details and specifications to address tie ins or transitions.

The history of cold climate vapor barriers itself is a story based more on personalities than physics. The product is designed for wall assemblies that need a vapor permeable air barrier. They dramatically improve building energy efficiency indoor comfort and longevity.