Chimney flashing done wrong on new roof

My installer didn’t know how to correctly flash a chimmney so what he did leaks under the shingles accross the roof deck and down the siding. What can be done now? Last spring I replaced the installer"s caulk job but it only lasted a few months. It’s a new asphalt shingle roof over flake-board deck. The chimney surrounds a metal fireplace pipe and is consructed of 2 by 4 framing covered by lapped cedar siding. The builder’s flashings were sheet aluminum on each side of the chimney “box” bent up to shed water but the design ends up sending water under the shingles. Do the existing shingles need to be taken up or can flashings still be properly inserted? It would be possible to dismantle the chimney and rebuild it with proper flashings if that makes more sense than tearing into the shingles. Thanks, Bob T

Yes the shingles will have to be removed to do the job properly. Not all the shingles but the ones surrounding the chimney. You should hire a roofer to do this because reflashing a chimney isn’t really a diy job. It isn’t uncommon for me to get a call to reflash a chimney (not ones I did origionally) and I assume most other roofers do it fairly often too.

To: Island Roofing. Thanks for the quick response. I was hoping for a simpler repair but figured that wasn’t possible. Thanks for the advice, Bob T

Could you take a couple photos? It kind of sounds like your contractor didn’t install what is called kickouts at the bottom of the flashing and water is running in behind the siding at the bottoms because it has no choice but to do so. If your chimney is at the bottom and not all the way on the roof this could be the problem. I see it all the time. But without photos its too hard to tell. If thats it then there is a real quick and easy fix. Assuming “nothing” else is wrong but that.

Lucky: There’s still about a foot of snow on the roof obscuring the base of the chimney (I’m in far northern Wisconsin). So photos would take some time yet. The roof has been frozen since Nov and only now has thawed enough to expose the leaking down the exterior siding. But when I did the caulking last spring I noticed that the flashing at the chimney “box” bottom went under the shingles, not over as I’ve seen in drawings. That may be the problem but maybe not the only error by the roofer. I may post photos yet since repairs will probably have to wait for the snow. Thanks, Bob T

I’m willing to bet the installer hand bent the aluminum flashing, but instead of bending a perfect 90 degree, it is just sort of rounded. I have seen this a few times and they’ve always leaked. It actually gives water momentum to get under the shingles lol.

Pics would definitely help though.

Bob, If water is being trapped on the inside of the siding, ( between the plywood box of the chimney and the siding. ) and is ruining the siding from the roof downward then this is your problem. If so, it can be fixed by cutting a small slit in the siding, installing a 6 inch piece of wall flashing on both sides of the chimney at the bottom and at an angle to “kick” the water into the gutter instead of in behind the siding. A small piece of the existing flashing may have to be cut out. And then you seal around the slit you cut of course.

O.K. I got out the roof rake and removed some snow to show the situation. Two pictures, posted on the gallery under 'bob t". As bcdemon guessed, the flashings are aluminum, hand bent and with fairly round corners. The photos show the bottom flashing going under the next row of shingles (which I’ve also learned is wrong). Luckychucky’s last post talked about correcting the leak under the siding. The one picture shows some light streaks in the siding where the water came outside the boards and washed off the stain. The leak is actually spread about four feet wide coming (probably) under the shingles but over the sheathing and then down the exterior wall behind the siding. To install the flashings the roofer tore off the chimney corners and some siding (pix shows aged and new boards). I suppose that step may also have to be repeated? This all helps as I feel that I need to know everything to get the right job next time. Thanks, all. Bob T