What is a chimney liner? A chimney liner protects the brick and stone interior of a chimney from heat damage and some of the corrosive by-products of fires. Chimney liners are required by many fire codes. By ProMatcher Staff Updated: 08/23/2016 Get Free Quotes Today! Get Free Quotes Today! Find Local Pros Free Build Masonry Chimney Cost Estimates Related Questions How Much Does a Level 2 Chimney Inspection Cost? What is a Chimney Damper? Should a chimney liner be insulated?Top answer: In most cases What is your opinion of the Chimney Safety Institute of America (CSIA)?Top answer: Favorable What type of chimney cap material is the least durable?Top answer: Aluminum