Construction – Under Slab Vapour Retarders – Optimum Performance



The use of under slab vapor retarders/barriers has long been regarded as an
effective, economical way to control moisture migration through concrete. The
proper installation of an effective vapor retarder/barrier beneath the concrete has
been proven to reduce or eliminate issues that arise when moisture migrates into
interior spaces, including the adverse effects such moisture has on floor covering
and coating systems, as well as compromised indoor air quality due to the
development of fungus, mildew and mold.

W. R. MEADOWS was the innovator that identified the problem early on relating to
vapor permeance and membranes getting punctured during installation. In the
1950s, we pioneered the exclusive PREMOULDED® MEMBRANE WITH PLASMATIC®
CORE that is still in use today when your retarder/barrier absolutely has to be
tough enough. While low permeability, high strength and durability are all
important selection and specification criteria for under slab vapor
retarders/barriers, there is some speculation about which of these performance
characteristics is most important when choosing the right vapor retarder/barrier for
a project. This paper explores the industry standards governing under slab vapor
retarder/barrier performance and identifies critical product characteristics that
should be considered when determining what level of under slab vapor protection to
specify for a particular application.