.....Moisture & Vapor Retarders
Moisture is one of the more
misunderstood aspects of building-shell performance. Different insulation materials exhibit different moisture handling characteristics. These characteristics must be considered in designing insulated assemblies. Glass fibers do not absorb moisture, however, moisture can condense within the insulation and migrate to parts of the insulated assembly that may be damaged. Fiberglass insulation is very susceptible to air ex filtration, the major cause of moisture migration into walls and ceilings. Ex filtration of moisture-laden air into walls and ceilings is the major moisture transfer mechanism. The low air permeability of |
cellulose all but eliminates this means of
moisture movement. Cellulose insulation demonstrates the ability to control moisture migration by eliminating air movement, making vapor retarders unnecessary when cellulose insulation is installed. Therefore, the Cellulose Insulation Manufacturers Association does not recommend use of a polyethylene vapor retarder with any cellulose wall installation, unless there are specific extraordinary conditions indicating that a vapor retarder would enhance the moisture performance of the wall. Increasingly, building science is coming down against prescriptive use of polyethylene vapor retarders. |
.....Air Infiltration
Uncontrolled leakage of air through exterior
walls and ceilings of homes is almost as important as R-value in determining how much energy will be required to heat and cool a building. This factor is all too often totally ignored in specifying insulation. Fiberglass is used as air filter media, and fiberglass in walls and ceilings behaves much as the fiberglass in an air filter. Air rushes right through it. During remodeling when old fiberglass-insulated wall cavities are opened, the batts are usually found to be covered by dust, just as an air filter would be. Cellulose insulation is very effective at sealing buildings against air infiltration. Controlled air infiltration is one of the most important factors for energy efficiency in the thermal performance of a building. |
Research shows cellulose to be up to 40%
better than fiberglass at controlling air infiltration. |
Standard Specifications
LICENSE #C32145
P.O. Box 4546
Kailua Kona, HI 96745
(808) 325-5888
mark@ecopacificinsulators.com
ecopacificinsulators.com
CONTACT US TODAY FOR A FREE QUOTE OR TO RECEIVE MORE INFORMATION
P.O. Box 4546
Kailua Kona, HI 96745
(808) 325-5888
mark@ecopacificinsulators.com
ecopacificinsulators.com
CONTACT US TODAY FOR A FREE QUOTE OR TO RECEIVE MORE INFORMATION