Q & A on What to Consider When Selecting
and Insta lling Air and Water Bariers
WORDS: MASONRY DESIGN, TIFFANY COPPOCK, COMMERCIAL BUILDING SPECIALIST AT OWENS CORNING
Air and vapor barriers can be viewed as unsung
heroes, defending a building enclosure and its
occupants from poor thermal performance, indoor
air quality, moisture infiltration, and the problems
that occur when moisture collects in the
enclosure. A 2017 Masonry blog post focused on
the critical functions of air, water, and vapor
barriers play in the building enclosure. How can
contractors building masonry enclosures select
the proper air and water barriers to not only meet
the architect’s specification but help the
enclosure deliver optimal performance? What are
some best practices when it comes to installing
air, water, and vapor barriers? What support is
available to help contractors navigate the
tremendous breadth of products available? To
address these questions, Masonry Design
magazine spoke with Tiffany Coppock,
Commercial Building Specialist at Owens
Corning.
MASONRY DESIGN: Last year’s blog post
mentioned that air, water, and vapor barriers
should be installed to function as part of an
enclosure system. What are some problems that
can arise when the enclosure system is not
considered?
Tiffany Coppock: It’s vital to have a working
knowledge of how air and water barriers work
together during the installation process and how
other products installed afterward may impact
performance. For example, after an air and water
barrier is installed in a masonry wall, its continuous
membrane will likely be punctured repeatedly
as other components are installed. With that in
mind, it’s important to think about the methods
used to install materials through the barrier. Are
you using a fastener that will require four penetrations
per attachment or are you using a single
barrel anchor fastener that requires one
penetration through the membrane? Does the
fastener maintain compression creating a
46 | Masonry Design
gasket effect for air and water tightness around
the membrane? We see a lot of power actuated
fasteners, but a common nail or stapler doesn’t
necessarily hold in compression over the lifespan
of a building. It’s important to consider whether
the same level of compression will exist several
years down the road.
The chemical compatibility of materials is another
consideration. You may have an asphaltic-based
flashing system, but your window manufacturer
requires a specific sealant to uphold its warranty.
A situation could arise where the asphaltic
flashing comes into contact with a noncompatible
silicone product. Incompatibility can
be addressed successfully, but ideally, these
considerations will be thought through during the
design stage.
MASONRY DESIGN: From a macro-level, how
are codes, extreme weather events and the labor
market influencing air and water barriers?
Tiffany Coppock: The original standards for air
barriers to pass the ASTM E283, E1677, E2178
or E2357 ASHRAE standards, targeted
performance at .4 CFM or lower. The E2357 tests
we see these days consider pressures applied
from the inside and outside and evaluated how
well the product was able to maintain continuity
and adherence to the walls and as a system.
Today there are a wide range of products – fluid
applied, peel-and-stick, self-adhered and rigid
board – and the majority of these products will
meet ASTM 2357. Now that the building
community has proved existing standards are
widely achievable, we may see code
requirements tightening as has already been
demonstrated on USACE projects.
A good portion of the innovation was being
driven by the government as a building owner
and the manufacturing community to improve air