Question about those old, unlined brick chimneys in historic districts

Three years ago, I was working on a house from the 1920s in the Old Town area here. The chimney was original brick with no liner, and the mortar was basically dust. I tried a standard brush but it just chewed up the soft brick. An older guy at the supply place told me to wrap my brush head in a thick wool sock, like the kind you'd wear for boots. It added just enough cushion to get the soot out without wrecking the old masonry. I still keep a pair of old socks in my truck for jobs like that. Has anyone found another good way to handle those fragile, unlined flues?

3 comments

3 Comments

the_jana3mo ago

I used to be all about the stiff wire brushes for any chimney cleaning job. That wool sock trick sounds a little silly, but it makes total sense for soft brick. You need that cushion to stop the scraping. I had a similar issue on a 1930s place and ended up using strips of carpet pad wrapped around the brush head. It worked on the same idea, just giving it a softer touch. Protecting the original work is way more important than getting it spotless.

danielh813mo ago

Yeah @the_jana, but carpet pad can leave fibers stuck in the mortar.

vals383mo ago

Tried the carpet pad thing once and it was a mess. Honestly just switched to using a soft nylon brush for old brick. Gets the job done without hurting anything.