Owens Corning specifies acceptable panel or board decking, spacing and surface condition for asphalt shingles. Gaps beyond its limits require correction, and shingles must not be installed directly over insulation board
Owens Corning technical bulletin: Roof Deck Requirements for Installation of Asphalt Shingles Technical Bulletin.
What this means for your roof
Owens Corning specifies acceptable panel or board decking, spacing and surface condition for asphalt shingles. Gaps beyond its limits require correction, and shingles must not be installed directly over insulation board. Deck quality influences both fastening and the finished roof surface.
A useful question for your contractor
Ask for the decking type, condition and gaps to be documented after tear-off.
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: August 2023. The date shown identifies the manufacturer document used for this summary.
Read Owens Corning: Roof Deck Requirements for Installation of Asphalt Shingles Technical Bulletin
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.