4.1001.6 Unvented Roof Deck—Preparation for Spray Polyurethane Foam

Topic: 
Attics
Subtopic: 
General Preparation
Desired Outcome: 
Backstop provided to prevent SPF SPF Spray polyurethane foam from entering soffit areas
TitleSpecification(s)Objective(s)
4.1001.6a
Surface preparation

Underside of roof deck will be prepared by sealing penetrations

Roof deck will be free of contaminants to ensure adhesion of foam

Ensure proper bonding of SPF SPF Spray polyurethane foam to substrate surfaces

4.1001.6b
Installation of insulation dams

Dams will be fastened to underside of roof deck and outside edge of exterior wall top plate to prevent SPF SPF Spray polyurethane foam insulation from entering soffit area

Installation will allow for the highest possible R-value above the top plate of the exterior wall

Ensure insulation R-value is not reduced

Minimize waste of SPF SPF Spray polyurethane foam

Ensure continuous insulation and air seal of exterior wall top plate and roof deck

4.1001.6c
Elimination of attic venting

All gable vents, ridge vents, and roof vents will be covered with suitable backstop material to provide substrate for SPF SPF Spray polyurethane foam application

Remove ventilation points when converting from vented to unvented attic

4.1001.6d
Removal of existing insulation and vapor retarder Vapor retarder A material that slows the passage of water vapor and contains a perm rating above 1

All existing attic floor insulation and vapor retarder Vapor retarder A material that slows the passage of water vapor and contains a perm rating above 1 will be removed

Ensure the new conditioned space is coupled with the house