How to measure the dry film thickness of a fluid applied air barrier

Installers know that once an air barrier installation is complete and the material has fully cured, the design team needs confirmation that the membrane measures to the dry film thickness suggested by the manufacturer.  

How do installers accurately measure the dry film thickness of a fluid applied air barrier? That’s a question our tech services team gets asked often. The answer begins with a distinction between types of gauges.

A wet-film gauge cannot be used to determine dry film thickness of air barriers.  The wet film gauge should only be used while installing the air barrier to confirm the wet film thickness.  Cutting out a piece of the membrane and trying to measure the dry film thickness after the air barrier has fully cured out is very inaccurate.   

One of the most reliable ways to measure dry-film thickness of an air barrier is to use a digital dry film gauge.  There are many different manufacturers of these gauges and they are typically very accurate.

A dry film gauge is fairly expensive, but makes verifying the dry film thickness of Air Barriers easy, efficient, and quickly resolves any questions regarding the installation. Investing in one will pay for itself in no time.