Chimney Liner Insulation. Mix with water in a ratio 3.5 parts of TherMix to 1 part water. Then pour around the chimney liner. 42 pound bag. Each bag fills 3.25 cubic feet. Seven to nine gallon of water mixes the whole bag. Pours easily and contains no asbestos. Thermix Insulation Availability: Usually ships the same business day PTMI42Regular price: $49.95Sale price: Copyright © 2012 Chimney Depot Inc. All rights reserved. Call Us @ 1-702-483-1587