Flashing a Stone Chimney

[SplitLog Libertarian]

Got a log house here, with a stone masonry fireplace and chimney. Chimney leaks because it's never been sealed to the roofing with anything other than tar (asphalt) Never been flashed.

Watched some step-flashing videos on YouTube, but those were all brick chimneys with even surfaces. Some used lead flashing, others copper. The chimney comes out at the peak, so the roof slopes away either side, which further complicates the matter.

Any ideas or experience with such a case will be gratefully received.

-- J.

[aemeijers]

If the mason did not build in step flashing as he laid it, at this point only practical solution is to pay to get somebody up there with a diamond saw to cut a groove to add flashing. There are companies that do that, at a not-too-outrageous price. I'd have them go ahead and flash it while they are at it. The right tools and scaffolding and experience make a big difference, and for one-time job, there are some skills not worth bothering to learn. IMHO, of course.

[SplitLog Libertarian]

Got to agree with that! Not to mention an investment in tools I'd never be apt to use again. One thought that occurred to us was to build a housing around the chimney to provide even surfaces--then the trick is to figure out how to flash that.

-- J.

[Jim Elbrecht]

Go with aem's suggestion. This is one of those 'hire it out jobs'. Those guys will come out with a big ass saw, scaffolding, a sheet-metal brake, & hopefully some experience.

They'll have it cut before you would have picked up a rental saw- the flashing will be bent just so and slide into the slot neater than you could have imagined-- and a steady hand on the caulk gun will seal that slot up so it doesn't need to be looked at again for 20 years. [and if it does- you don't get your ladder out-- you call them]

Jim

[DanG]

Call around and find someone who knows and understands counterflashing. Depending on how uneven the rock is, it can be done with a surface mounted counterflash with a caulk trough. You will also help the situation by installing a chimney cap that extends and drips rain water further away from the chimney.