GAF recognizes both assembly types when properly designed. Adding foam alone does not establish a complete unvented design; moisture control and existing openings must be addressed.
GAF technical bulletin: Vented and unvented attics faqs.
What this means for your roof
GAF recognizes both assembly types when properly designed. Adding foam alone does not establish a complete unvented design; moisture control and existing openings must be addressed.
A useful question for your contractor
Ask who will evaluate condensation risk and confirm the complete assembly.
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 revision: June 2, 2023. This is the date of the manufacturer source, not a claim that this website guide existed on that date.
Read GAF: Vented and unvented attics faqs
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.