A product specifically intended to be used as a base or first ply in a roofing system.
A saturated or coated felt placed as the first ply in a multiple-ply built-up roofing membrane.
A heavy sheet of felt sometimes used as the first ply in built-up roofing. French (Feuille de base)
a heavy felt that is used as the first ply in a modified bitumen roof system.
Saturated or coated felt placed as the bottom or first ply in a multi-ply built-up roofing membrane.
The first layer of roofing applied on the deck. Also, a dry or slip sheet.
An asphalt-impregnated, or coated felt used as the first ply in some built-up and modified bitumen roof systems.
An impregnated, saturated, or coated felt placed as the first ply in some low-slope roof systems.
a saturated or coated felt placed as the first ply in some multi-ply built up roof membranes.
