Relining your chimney gives you quite a few options for cutting corners. When relining your chimney, one corner I have seen be cut is no insulation being put around the new chimney liner. This is a huge mistake, and most chimney professionals would agree. In order for most reline jobs to meet UL Listing Standards, insulation is generally required. This, of course, can vary by manufacturer,
but many reputable chimney liner dealers operate this way, and not without good cause.
A chimney liner which is insulated provides benefits that go beyond merely meeting UL Listing Standards. Chimney liners that are insulated helps to prevent the extremely high temperatures found in the flue system from spreading through the masonry chimney itself to combustibles. Similarly, the insulation keeps the flue system itself warm such that the gases are able to draft up and out of the chimney at peak efficiency. An insulated chimney has, through observation over time, less creosote than a non-insulated chimney. Because the chimney flue stays warmer when insulated, creosote in its vapor form has less of an opportunity to rest and cool on the liner’s surface. By preventing condensation of creosote, you prevent creosote build up.
What type of material should be used to insulated a chimney liner? We recommend foil face insulation blankets made of ceramic fibers. These blankets are wrapped directly around the pipe, taped at the seam with foil tape, and then covered with a wire mesh which prevents the insulation from being damaged as it is lowered down the chimney. The ceramic fibers are the main insulator in this system, but the foil facing also is an insulator.
It is convenient to buy all of your insulation supplies in a kit. A kit should include the actual blanket, tape, the wire mesh, clamps for attaching the mesh, and spray adhesive. Often times you can purchase your liner kits precut to fit the length and diameter of the flue system that you are going to insulate. This makes the process very smooth and saves you additional work as well as waste. By purchasing only the amount that you need, you are able to save money in addition to time.