GAF Full-Deck Leak Barrier: Balance Water Protection and Drying
Bulletin dated: February 1, 2021 revision
GAF explains that full-deck self-adhering protection can reduce water entry while also restricting vapor movement. The assembly needs a moisture-control design that addresses indoor humidity, temperatures and ventilation
GAF technical bulletin: Full deck coverage english.
What this means for your roof
GAF explains that full-deck self-adhering protection can reduce water entry while also restricting vapor movement. The assembly needs a moisture-control design that addresses indoor humidity, temperatures and ventilation. Adding more membrane without considering drying can create a different roof problem.
A useful question for your contractor
How will the attic and roof deck manage moisture with full-deck membrane coverage?
Ask for the answer to be tied to the actual roof condition and the exact product being installed. Keep the agreed repair or installation detail with your estimate and project photos.
Bulletin dated: February 1, 2021 revision. The date shown identifies the manufacturer document used for this summary.
Read GAF: Full deck coverage english
This homeowner summary explains the cited bulletin. The complete manufacturer document and current product instructions govern the installation details. A requirement for one manufacturer or product should not be transferred to another without checking.