The bulletin details valley liner, metal flashing, laps and two shingle-edge methods. The bleeder-shingle approach and the alternate cut-shingle approach have different cement and fastening details
Owens Corning technical bulletin: Open Valley Technical Bulletin.
What this means for your roof
The bulletin details valley liner, metal flashing, laps and two shingle-edge methods. The bleeder-shingle approach and the alternate cut-shingle approach have different cement and fastening details. Mixing individual steps from the two methods can interfere with drainage. The alternate drawing and text also show different cement-width labels, so that detail needs manufacturer clarification.
A useful question for your contractor
Ask which complete valley method is specified and request clarification of any conflicting detail before installation.
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: April 3, 2020. The date shown identifies the manufacturer document used for this summary.
Read Owens Corning: Open Valley 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.