Premier mix insulation is a UL listed (to 1777), ready mix vermiculite based masonry material containing no asbestos. It helps keep heat in and allows the flue to stay warmer causing less creosote build up and less condensation in gas and oil applications. Simply prepare by gradually adding 2 to 4 gallons of water. The product is properly mixed if when squeezed in your hand, it will hold together, no water should come out. Pour the mix around the chimney liner and let it solidify.