Air Barrier Vapor Permeable

Greater than 10 perms.

Air barrier vapor permeable.

If it s really low it is a vapor 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. 10 perms or less and greater than 1 0 perm.

Ccw provides three types of air barriers. Perm a barrier npl membrane protects above grade wall assemblies against the damaging effects of air and liquid water ingress on building. Air shield lmp stops the movement of air while at the same time allowing the passage of vapor. If the perm rating is greater than 10 it.

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. 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. Permeability values of materials are irrelevant in air barrier systems.

Primer is not required on most construction surfaces. Materials with lower perm ratings are better at stopping the movement of water vapor. 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.

Although 6 mil polyethylene is an excellent vapor barrier it is often a very poor air barrier. They dramatically improve building energy efficiency indoor comfort and longevity. 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.

Vapor barriers are also a cold climate artifact that have diffused into other climates more from ignorance than need. 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. Air shield lmp is also a single component liquid applied vapor permeable air liquid moisture barrier.