Do I Need a Chimney Liner?
In a word, yes. Of course you need a chimney liner. If you had to ask that question, a little lesson is in order. If your neighborhood chimney sweep flew up the flue and came down declaring you needed a new liner, you want to make an informed decision. To make that informed decision you need information. You can hardly be expected to decide if you need something if you don’t know what purpose the something serves.
A chimney liner protects the interior of your chimney from corrosion, ensures that the smoke and fumes from your heating systems exits your home unrestricted. They also serve to reduce the temperature of the chimney while it’s being used. The chimney sleeve runs from the top of your furnace to the bottom and it is not only important that it is intact, but that it’s the correct material for the fuel you are burning, and that it is the right size for your chimney. The chimney must be warm to create the updraft needed for the smoke to rise through it. The liner keeps the exterior of the chimney cooler, but helps to warm the interior. If the liner is too small or too large, it won’t create sufficient updraft and smoke or fumes could enter your home.
There are many reasons you may need a new liner aside from age. Liners can be damaged by lightning strikes, fireplace fires, or when your foundation settles. If you bought an older home, it may have settled by the time you purchased it, but you have no way of knowing how well the prior owners had maintained it, unless you asked. Without this knowledge, you could very well need a new liner. If the liner is damaged, water and flue gases can reach the mortar joints. They will deteriorate over time and will have to be replaced. You also increase your risk of a chimney fire.