Just like with cleaning a house there is no set rule of how often your chimney should be cleaned. Whilst a house can go a while without a good sweep, a chimney is not the same and in fact not doing so can be extremely dangerous. What many people with wood stoves don’t realise is that when incomplete combustion occurs, creosote forms throughout the chimney. Generally large amounts will build up if you have a smoky fire that is being allowed enough oxygen which is why is important to provide adequate oxygenated air in your stove. However, regardless of how careful you are, creosote will build up and needs to be cleaned for the safety of you, your home and the surrounding properties.
How to check if my chimney needs cleaning?
In order to check to see if your chimney needs sweeping you must look for the build-up of creosote. The first step in ding this is to check that there is no downdraft coming from the chimney. If you are having trouble checking, tape a tissue to the open part of the stove and watch for any movement of downward air. If you do feel any air you should open surrounding windows and doors until the draft stops or begins to move upwards. Once this is done put on a pair of gloves and a dust mask, then get a flashlight and a fireplace poker and scratch the surface just above the stove chamber. If there is barely a mark then you do not need to clean your chimney just yet, if however it is any thicker than this it is important that you schedule a chimney sweeping/cleaning as soon as possible. In the meantime do not light your fire as you are putting your stove and chimney at risk of catching fire.
How the chimney is cleaned?
Just like you would see in the old movies, the first layer of creosote can be removed with a chimney sweep brush as it is extremely light and sooty. The next layer is slightly thicker and more granulated but can again be removed with the same stiff chimney sweeping brush. The next layer is a tar like substance and dries very hard so can be a lot harder to remove even with a stiff brush so needs scraping equipment. The last and most dangerous coating of creosote is shiny and is almost impossible to remove which is why your chimney requires regular cleanings to ensure this stage isn’t reached.
Whilst you could potentially undertake this job yourself it is highly advisable that you instead hire a professional and licensed chimney sweep.