Use the following guide to select the proper
Chimney Brush for your chimney.
Measure the inner
opening (both directions) of
your fireplace or woodstove chimney.
For masonry chimneys you'll need to measure the inner opening dimensions
in both directions. Buy a brush that is at least as big as your
chimney liner otherwise it will not reach the side walls of your
chimney and won't do an adequate job. If you buy a chimney brush
that is too big then it will be harder to get down the chimney but
will work unless excessively oversized.