Product Brochure

4
Water Resistance

Vapor Permeability

as it affects everything from comfort and IAQ to the energy efficiency
of the building envelope.
Durability

the rigors of the job site and last for the lifecycle of the building.

®


and moisture protection in new construction and additions. Two
of these flows — air and moisture — can be easily addressed by
understanding how the mechanics of the building work and knowing
which solutions can be leveraged to accomplish your goals.
Understanding 2012 & 2015 IECC Requirements

R402.4.1.1, “Air Barrier and Insulation Installation.” The table is based on

envelope. However, while the previous codes allowed a blower door test to substitute for the checklist, the 2012 and

When it comes to air infiltration and exfiltration, “air out always equals air in,” meaning that an interior air barrier can
block air flow equally as well as an exterior air barrier. In fact, in terms of practical application, an interior air barrier
generally outperforms exterior ones such as housewrap over the lifecycle of the building. In fact, housewrap is subject
to several known failures — rips, tears, blown-off wrap — which can cause multiple breaches in the continuous air
seal needed. An interior air barrier is far better protected from these hazards and offers a number of other advantages
over exterior barriers:




Common Methods
Exterior Air
Barriers
Interior Air
Barriers

Membranes
Spray-Polyurethane

Insulation Board
Polyethylene Vapor
Retarder Sheeting
Pre-bonded membranes
Smart Vapor
Retarder
Water-Resistive
Barriers (WRBs)

– Self-Adhered
Air-Tight Drywall
Approach

& Seal
Climate Zone Temperature
Required ACH
(Air Changes/Hour)
Vapor Retarder
Required
1, 2 & 3
Hot & humid, very few heating days 5 or less No
4
Mixed climate — hot & humid, with several
heating months in the winter
3 or less No
4C (Marine),
5, 6, 7 & 8
Mixed climate — hot & humid, with several
heating months in the winter
3 or less Yes