Hurricane Roof Leak - Chimney flashing help

[Roots&Wings]

Hurricane Irma left my house with a roof leak (thankfully minor in the scheme of things). Does anyone have any tips for repairing a leak around copper chimney flashing?

Both products I was considering (Peel & Seal and Leak Stopper) are out of stock here at Lowes (and would likely look terrible patched around the copper). The shingles run tight under the flashing, and the exact location of the leak is impossible to pinpoint along the left side.

The guy at Lowes recommended running clear Leak Stop caulk all around the bottom edge and side gaps when it's back in stock, however, this seems like a large area for caulk.

Any ideas/suggestions appreciated!

[lthenderson]

I would not put caulking of any sorts around the bottom edges (either horizontal or vertical) of the flashing. Those gaps are to allow any water intrusion a way out to the top of the shingles and down to the gutter. By damming it up with caulking, you are essentially just creating a water reservoir underneath the flashing and shingles and amplifying your problem.

On a correctly flashed chimney, unless the flashing comes untucked from the brickwork, I rarely see leaks just springing up along the sides. From your picture, the flashing looks firmly tucked into the grout lines but a close inspection would better to make sure their isn't cracks allowing water to get behind it. The most common place I find leaks is in the chimney cap itself or sometimes on the uphill side of the chimney where the roof saddle should be located. This helps to funnel the water around the sides of the chimney but isn't visible in your picture.

[Roots&Wings]

Thank you lthenderson! That is what I was afraid of. Would it be safe to caulk underneath the flashing (not sealing the flashing) where the shingles meet the chimney stone? I crawled into the attic (practically no space) and the water leak does seem to be right along where the roof meets chimney, about halfway down the chimney.

[Jon Bon]

I would not put caulking of any sorts around the bottom edges (either horizontal or vertical) of the flashing. Those gaps are to allow any water intrusion a way out to the top of the shingles and down to the gutter. By damming it up with caulking, you are essentially just creating a water reservoir underneath the flashing and shingles and amplifying your problem.

On a correctly flashed chimney, unless the flashing comes untucked from the brickwork, I rarely see leaks just springing up along the sides. From your picture, the flashing looks firmly tucked into the grout lines but a close inspection would better to make sure their isn't cracks allowing water to get behind it. The most common place I find leaks is in the chimney cap itself or sometimes on the uphill side of the chimney where the roof saddle should be located. This helps to funnel the water around the sides of the chimney but isn't visible in your picture.

I guess it depends on what you want to do.... for a stop gap issue using any type of black tar is worth a try, it costs a few dollars.  I have climbed up on the roof and smeared that stuff all over the place. It held for a year (and probably longer) until I paid to have it professionally done. It was definitely worth the $10 for a gallon of the stuff to fix an active leak ASAP.

If your looking for a >5 year fix reflashing the chimney ($500-1000) is probably what you need to do.

[lthenderson]

Thank you lthenderson! That is what I was afraid of. Would it be safe to caulk underneath the flashing (not sealing the flashing) where the shingles meet the chimney stone? I crawled into the attic (practically no space) and the water leak does seem to be right along where the roof meets chimney, about halfway down the chimney.

Leaks can be tricky to find. The leak (where water is penetrating the shingle layer) can still be happening well above the midway point of the chimney and the water just runs down the sheathing underneath the shingles to where you see it coming in from your attic midway down the chimney.  From the attic all you can tell is where it is penetrating the sheathing through a joint or a nail hole, not the shingles. The best way to find this is to get up on the roof and inspect it closely. Look for damaged shingles, cracks or flashing that has come loose.

[Roots&Wings]

Unfortunately there are no obvious cracks/holes or shingle damage. Maybe this is just a freak leak from 8"+ of sideways driven rain at hurricane force winds. I'll setup a drip pan and bucket in the attic in the meantime, and try to get someone more knowledgeable out soon for a closer look, since it sounds like my initial patch plan per youtube DIY videos would have created more damage.

And thank you JonBon for the temporary patch ideas.

For anyone who hasn't gone through a natural disaster like this, DIY skills are essential. Even if you want to hire someone for a professional fix, roofers are looking at over 1 month to even stop by, if you're lucky enough to reach one.

[paddedhat]

There is a really good chance that you had a ton of water that ended up getting blasted sideways into the top of the chimney. It happens, and there is no way to prevent it, nor anything to address once the building dries out. Lots of time and money gets wasted by homeowners and even pros. who fixate on the "fact" that a leak at a chimney is a roof flashing issue. A lot of issues are from water that penetrates the masonry ABOVE the flashing. This could be anything from a one off event like you faced, or degrading masonry, flashing or sealing at the top of the thing. Rebuilding the top 2-4' of an entire chimney to stop leaking is a pretty common situation. My parents had to do a major rebuild of their 70-80 year old, all brick chimney, and the top few feet of the stone and brick one, on our 60 year old place, was rebuilt with a new cap and stainless steel flue caps, a few years back.

[Roots&Wings]

Thank you paddedhat! That's encouraging to hear. There were no leaks pre-hurricane, and more rain expected tomorrow so I can verify if this was simply a rare issue with the sideblasting hurricane rain, or a recurring leak under normal conditions. I inspected the masonry above the flashing thoroughly, and it's still in good condition. Thanks for the helpful info.