Installation Guide Underlayment

Caution: Always follow Safety Instruction, Building Codes and Safe Work Practices issued by the local Govt. bodies (e.g. OSHA / WCB)

Westman Steel Underlayment products should be installed with Plastics Cap or Metal Cap nails with either ring shank or smooth shank Nails. DO NOT USE STAPLES. Use of staples will void the Manufacturer’s warranty.

Westman Steel Underlayment products are a secondary layer protection approved for installation over Plywood with proper fasteners. Westman Steel Underlayment is an air, vapour and water barrier with <1 Perm.

Lay out horizontally with printed side up using 6” vertical laps and 4” horizontal laps. The overlaps ensure that the water runs over the overlaps without getting under the material. Before installing the underlayment ensure that the roof is clear of any debris or any sharp protrusions.

Product must be attached to the roofing structure using 1” plastic or metal cap nails. Product must be fastened with the nail pattern printed on the product. All anchoring must be performed fush to the roof, 90 degrees to the roof deck that will hold the material tightly with the plywood. The use of every other anchoring location printed on the product is also acceptable.

For prolonged exposure, double the overlaps and use every anchor location. Product has 90 Day (Silver) and 180 Day (Platinum) UV protection but it should not be considered a final roofing system. A proper final roofing system should be installed over the product to get the proper protection. Product is a secondary barrier used over plywood, under a roofing system like wood and asphalt shingles, tiles, slate and metal roof.

Safety Notification:

Westman Steel Underlayment products are designed with the GRIPSPOT technology for better skid protection for the roofer but product may become slippery due to high moisture, frost, rain, water, dust, debris or other conditions. Use precautions when working on the roof. Follow all local and federal safety codes when installing any roofing system including Westman Steel Underlayment products. Failure to adhere to those procedures may result in serious injury or even death.

Single Layer Application of Westman Steel Underlayment

For slopes greater than 4:12, Westman Steel Underlayment should be installed horizontally starting from the bottom of the roof with 4” overlaps working up the roof.

Double Layer Application of Westman Steel Underlayment

For slopes 2:12 to 4:12, Westman Steel Underlayment should be installed horizontally starting from the bottom of the roof with 25” overlaps working up the roof.