Monthly archive for March 2015

White Paper- Vapor Barriers (Retarders) and Air Barriers

Air and moisture can get into a home a number of ways. Convective transfer involves moving air, such as adraft around a window or door, electrical boxes, or other wall penetrations. Diffusion refers to moisture moving through a material, similar to a sponge soaking up water. Cavity wall construction typically with fiberglass battsplaced into the cavities between studs allows air to pass through, and requires an additional, separate vapor barrier, typically polyethylene sheet (Visqueen) or kraft paper facing on the fiberglass batts. Continuous insulation (EPS foam or XPS foam) can also be used as a vapor barrier. Vapor barriers, or more properly worded,retarders, must


White Paper- R-value and Performance of BuildBlock and BuildLock Knockdown Insulating Concrete Forms

The R-value is a measure of thermal resistance used in the building and construction industry and is generally understood to indicate how efficient the insulation value of the material or product. R-value under uniform conditions it is the ratio of the temperature difference across an insulator and the heat flux (heat transfer per unit area per unit time, QA) through it or R=ΔT/QA. Thermal resistance varies with temperature but it is common practice in construction to treat it as a constant value. (A common method is to standardize the temperature at which the values are reported. (75° typical) (1). BuildBlock