Blew a hole through a chimney crown last Tuesday

I was cleaning out a 20-year-old flue in an old house near downtown. Got too aggressive with the steel brush and punched right through the crown, concrete dust everywhere. Had to patch it with hydraulic cement, cost me about $50 in materials and an extra 3 hours of work. Anyone else ever accidentally busted through a crown and had to do a quick on-site repair?

3 comments

3 Comments

danielmartinez1mo ago

Nah, I can't get behind this one at all. You're framing it like it's a normal mistake but punching through a chimney crown is almost always bad planning or rushing the job. A steel brush doesn't just randomly go through solid concrete unless you're using way too much force or the crown was already cracked and you didn't check it first. If you had to spend 3 extra hours on site that's on you for not spotting the weak spots before you started cleaning. The cement patch might hold for now but that kind of repair never lasts as long as a proper crown replacement. Honestly, this sounds like a lesson in slowing down and looking closer at what you're working with.

margaretf401mo ago

@danielmartinez your point about the patch is off though, a good cement patch can outlast a full replacement if you do it right.

felix_jones1mo ago

You're framing it like it's a normal mistake but punching through a chimney crown is almost always bad planning or rushing the job" - see, I get where you're coming from, but I think you're being a little hard on the guy. I've been doing this kind of work for years and sometimes old concrete just gives up the ghost even when you're being careful. That steel brush can catch on a hairline crack you didn't even see and the next thing you know there's a hole. It's not always about rushing, it's about old materials being unpredictable. And that hydraulic cement patch he used, if he cleaned the area good and packed it tight, it can hold just fine for a long time. I've seen patches outlast original crowns in some cases because the new cement bonds better than the crumbling old stuff.