When someone tells us that a certain “smell” is coming from their chimney system, we ask them what type of smell it is. The reason we do this is simple; there are several different things that could be causing the smell from something lodged is the flue, water or just from the neglect of cleaning. But before we get to the cause, let’s talk about why you smell something from your chimney in the first place.
Chimneys are designed to take smoke, CO2 and other materials produced by fire out of your home through the flue. When not in use, chimney’s still act the same way. However, if there are gaps, cracks and leaks in the liner, chimney cap, crown then air is being introduced into the system. This can cause the air flow to change and be pushed out the firebox into the home instead of up and out the flue into the atmosphere. When this happens, whatever is in the chimney that smells is entering your home.
If you have not had your chimney cleaned and swept in a few years, the smell in the chimney may just be from a build up of creosote. Many people describe this smell as “barbeque”. Some also complain about headaches and upset stomachs associated with the smell as well.
Creosote is just one of the byproducts of a fire. What makes it different from some of the other is it has a tendency to stick to the walls of the liner much like you would think of plaque in your arteries, which build up over time. However, unlike your arteries, we can go into the flue and clean this stuff completely out. This will normally take care of the smell. Also, during an inspection, we can also see if there are any cracks, gaps or other types of leaks that have developed in the system and discuss with you what can be done.
Another cause of having a smelly chimney is water. This can create a damp or musty smell in your home. Depending on the type chimney system you have, water can collect in several places, including behind the smoke chamber. As it collects it can also absorb smells in the chimney and produce a musty, sometimes mildew type odor. Fixing this means finding and repairing the source of the leak with a good sweeping.
If animals are allowed in the chimney through an open flue or damaged cap or damper, they can do one to two things to cause odor issues; leave you “presents” in the form of body fluids or get into the chimney and die trying to get out. Both of these smelly problems can be eliminated by cleaning the chimney and placing a chimney cap with a mesh to keep small animals out of the system.
The final problem doesn’t happen often but we do see it from time to time so wanted to include it in our list. This is when you have started to compost dried leaves that have fallen into the chimney and settled on the backside of the damper blade. This creates a “rotten-smoke” type smell produced by the composting effect of the leaves mixed with creosote and other smoke riddled debris in the chimney system. Again, this can normally be fixed with a good cleaning and a cap with a mesh to keep debris out.