Have been investigating leak on my 3 season room. Not certain it is related to this finding but discovered flashing around my chimney in an interesting state.

Big gap in corner and also the epoxy/sealant that the flashing was pushed against at the top of the flashing was not sealed/tight anymore (suspect water was getting under/behind it) - I caulked this up. Peeking inside of this gap I can see a varied state of wood.

  • Should I install some sort of kickout flashing?
  • Can/Should I gap fill this with caulk/foam - we had yellow jackets in the wall on another side of the house we disposed of so I know they'll be looking for a new home this year.

Apologize that the last few images are bad, they're from a 3rd party app to use the cheap amazon boroscope.

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Inside the gap

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    I'd probably do all those things, not knowing how the leak presented itself. Use sealants designed for roofing, though. Foam isn't, nor is standard caulk like latex or silicone. – isherwood Jan 3 '19 at 14:45
  • 3-Season room is about 15 feet in a downward slope to the right of this situation, so it's possible. This was a bonus find. I'll investigate some sealants. I was using DymonicFC when I touched it up but am assuming I'll need to redo that. /Cheers. – TEEKAY Jan 3 '19 at 14:55

You should caulk this with the best exterior caulk you can buy (doesn't have to be roofing, but do NOT use latex caulk for this). Don't use expanding foam, as it's not waterproof.

You might want to double check and make sure there's no lasting water damage (i.e. wood rot) before you do.


I'd recommend a urethane based sealant like . BASF Sonolastic NP-1

It's stays flexible and I've had a lot of success with it. It can be a pain to use however. Whatever you're caulking MUST be dry or the caulk will roll right off. The other pain is cleanup. But IMHO the pros far out weigh the cons.

One other thing I noticed is that your counter flashing isn't tucked into your chimney. When I install counter flashing, I bend it in such a fashion that there is a 1/2" of material that can be tucked into a groove that's been cut in to chimney in this case. This gives me an actual surface to caulk.

It appears to me that the top of your counter flashing is bent out and away from the chimney.

Also, as @Machavity suggests, I'd determine if there's any rot and repair it first if there is any.

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    Appreciate the sealant recommendation. You're correct, someone created some sort of lip with a sealant (it's quite hard) and it was just pressed against it. – TEEKAY Jan 3 '19 at 15:31

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