Boral® Ply 40 is an SBS modified fiberglass reinforced underlayment/base sheet for tile, shingle or shake.
SBS modified asphalt minimizes wrinkling & buckling associated with non-modified membranes.
Durable Protection – All Seasons
Easy Installation
90 Days Uncovered Exposure
10 Year Limited Manufacturer's Warranty for one layer
20 Year Limited Manufacturer's Warranty for two layers