Contractors say that when choosing a membrane air barrier for concrete masonry walls (CMU) covered with drained exterior cladding, liquid-applied membranes are clear winners over sheet applied membranes. The reason is clear. Rough, irregular surfaces with embedded masonry ties are much easier to cover using a liquid (either spray or roller applied) than sheet membranes.
But a successful application is not as simple as point and spray (or dip and roll). First, contractors must consider the system’s base components. Years of testing has shown synthetic polymer liquid-applied systems provide a three-fold performance advantage over asphalt-based systems including:
Other considerations for installing a highly effective liquid-applied AVB membrane over CMU covered with drained exterior cladding are: surface preparation; careful monitoring of membrane thickness; and choosing proper accessory materials to provide a continuous installation.
- * Increased UV resistance
- * Superior flex and elasticity
- * Better fire resistance
Go here for an overview of things to consider when your next job specifies an air and vapor barrier installed over CMU with drained exterior cladding.