Roofing Underlayment is a 40 mil selfadhering sheet membrane used for protecting roof substrates against water penetration from wind driven rain and water back-up caused by ice dams.á This
membrane is used in new construction
and re-roofing beneath single-ply roofing,
metal, slate, tile and asphalt shingles.á
The membrane will
self-adhere to clean wood,
plywood,
and metal and by using a primer will adhere
to precast concrete, cast-in-place concrete,
and lightweight structural concrete.á
Roofing Underlayment is comprised of a strong, skid resistant polyethylene film laminated to a thick layer of highly adhesive rubberized asphalt.á A
siliconized release sheet is used to prevent
the material from sticking in the roll, and is easily stripped away for installation.á The membrane adheres tenaciously to the deck, permanently bonds to itself at the laps and provides a seal around nails or other fasteners that penetrate the deck during installation of the primary roofing material.