Products / AldoSil 399 Silicone Mastic

AldoSil 399 is a high-solids, non-shrinking one-part silicone mastic for sealing roof penetrations, curbs, seams and flashing areas ahead of a silicone coating. Its technical data sheet lists 92.5 percent solids by weight and 90 percent by volume, 379 percent elongation and 235 psi tensile strength (ASTM D2370) and VOC under 50 g/L, in white, gray and black, and states it must be top coated in all warranty applications.