Any home that is fitted with a fireplace or a combustion heater such as a wood-burning stove is going to eventually require a chimney brush. The more fires that have been lit in a fireplace or wood-burning stove the build up of soot and other residue in the chimney is going to require cleaning.
There are a couple of important factors to take into consideration when buying chimney brushes to ensure that you buy the right ones. Chimney brushes are available in a range of sizes. This stands to reason seeing as how chimneys are not all the same dimensions. Before buying a new chimney brush you should have first measured the interior of the chimney to be sure that you get one that fits.
Chimney brushes are available in a variety of shapes as well. A round chimney can be cleaned with a circular chimney brush while the older, more traditional square or rectangular chimney is going to require a square chimney brush.
Chimneys differ in the materials used to make them. A brick chimney can be cleaned with a stiff metal chimney brush that will scour the bricks clean. A metal chimney will require a softer, gentler chimney brush made of a polypropylene filament that will remove the coal and oil soot without damaging the interior of the chimney.
Apart from the need to remove soot and ash your chimney brush will have to be used to keep your chimney flue free of creosote buildup to prevent a chimney fire. Creosote is extremely flammable and can readily fuel a fire.
One thing to remember is that using an oversized chimney brush will not improve the cleaning action. In fact, it is more likely that the brush will become caught in the chimney. On the other hand a chimney brush that is too small will not provide the necessary pressure on the wall of the chimney to perform the necessary cleaning action.
There are four different methods that may be used to control the chimney brush during cleaning.
Top Down: The first step is to seal off the fireplace or stove opening so that the soot does not enter the home as it is dislodged. Using a flexible rod attachment you can secure the brush before lowering it into the chimney from above. As you work you simply add more rods as needed until the brush has worked its way to the flue bottom.
Bottom Up: A messier way to perform the same operation is to insert the brush attached to the flexible rods through the fireplace damper. This is not a preferred option because the fireplace cannot be sealed to avoid soot from escaping into the home.
Line and Weight: With this method you can seal off the fireplace and then attach a weight to the end of the brush and then attaching the brush to a rope. Lower the brush to the bottom of the chimney and then pull it up before lowering it again and continuing on until the chimney is clean.
Dual Line Method: This method requires two people to perform it. A rope is attached to either end of the brush and then the rope is dropped down from above to the person below. Alternately, each person will pull on the rope, dragging the brush up and down against the sides of the chimney. This is another messy option because the fireplace opening cannot be sealed whilst performing it.
Here is some more information about cleaning chimneys.