Old timer showed me the string trick for soot dams in curved flues

I was up on a steep roof in Portland last Tuesday trying to clear a soot dam in a curved flue. My rods kept binding up about halfway through and I couldn't get past the bend. I tried different brush heads, less pressure, even a smaller rod section. Nothing worked for like 45 minutes. Then this old sweep who was working on the house next door walked over and showed me his trick. He tied a heavy steel nut to a length of paracord and dropped it down from the top of the flue. Once it passed the dam, he tied his brush to the bottom end and pulled it back up through the dam from below. It cleared everything in about two pulls. Has anyone else used this string method for tricky flues or do you have a different approach?

4 comments

4 Comments

jessica70716d ago

Nah is this really that deep though? I mean yeah it sucks when your rods get stuck but 45 minutes isnt exactly a crisis lol. Just hit it with a shop vac from the bottom or something. I feel like people overcomplicate chimney stuff sometimes. Its just soot not rocket science.

blair_nguyen16d ago

Forget shop vacs or simple fixes, try thinking about what happens when that stuck rod finally lets go. If you've been cranking on it for 45 minutes and it snaps back, you could crack the flue liner or knock a whole section of creosote loose that falls and blocks the damper. Now you're calling a sweep anyway, plus paying for a camera inspection to check for damage. That "quick fix" shop vac idea sounds great until you realize you just shoved a loose brick or a wasp nest into your fireplace. The real cost isn't the time, it's the hidden damage you cause by forcing it.

wade25016d agoTop Commenter

Did you see that thread where a guy's rod actually snapped in half?

baker.holly6d ago

A buddy of mine tried the shop vac trick last winter. He hooked it up from the bottom and just went to town for a good 20 minutes. Pulled it off and the whole thing was fine at first, but then he lit a fire two days later and smoke just poured back into the room. Turns out all that suction just packed the debris tighter into a little shelf in the flue, and the heat loosened it up enough to drop down and block the damper halfway. He ended up having to call a sweep who basically said he made a 30 dollar problem into a 200 dollar one.