100% polyurethane construction adhesive may be used inside or outside and will last as long as the surfaces it joins together. 8 times stronger than traditional construction adhesives and has 4 times the initial grab than the original PL Premium formulation. Repositionable and virtually VOC free. Recommended for bonding most common construction materials such as wood, treated wood, hardwood flooring, concrete, stone, marble, slate, masonry, brick, foam insulation of all sorts, carpets, metal, lead, cement base products, ceramic, fiberglass, drywall, and mirrors. Waterproof. Gray.