ASTM E96
Standard Test Methods for Water Vapor Transmission of Materials
What it measures
Measures how readily water vapor passes through a material, reported in perms.
Why it matters for a panel envelope
Vapor permeance decides where a wall assembly can dry to, which is the difference between a durable wall and a moldy one.
Guardian Shield™
Cited in the Shield™ specification's reference standards.
Source · 3-Part Specification, 1.3 F.16 · Guardian documents
Published by Guardian Structural Technologies. Last updated .
Drafted from our product literature and published building-science sources. Awaiting our technical review. Confirm any figure against the current product documents or ask us before you rely on it in a design.