Flashing problem around chimney

meanwhile · #1 10/31/10, 09:04 AM

Recently we had a whole new metal roof installed by Professional Roofer. The area around our main large chimney is leaking in one place. He has come back out to caulk and adjust the flashing two times now but last week, in the huge rain storm we had, it leaked the whole time.

This same chimney leaked even before the new Roofer. So - I know it is a problem with the chimney and not the Roofer.

But - I have to find a way to stop that leak. The chimney is a stone huge tall chimney and what the Roofer says is that one large stone sticks out and makes it impossible to press the flashing flat to the stone. He did caulk around it but it then pops the flashing back outwards - then it leaks.

What can I do? I have to stop this leak. Thank you for ideas.

Windy in Kansas · #2 10/31/10, 09:09 AM

Use lead sheeting for the flashing and conform it to the shape of the stone.

mistletoad · #3 10/31/10, 09:22 AM

We had no end of problems until DH discovered "Ultra Roof 1000" at Lowes - it goes on with a paintbrush and adheres to anything (shingles, masonry, flashing, caulk etc). It is white so it might be noticeable.

swollen tongue · #4 10/31/10, 12:33 PM

use some "Ice Shield" around the area..........it might stop the leak

rambler · #5 10/31/10, 12:39 PM

Masonary saw & cutting a groove for the flashing will cure it if done right, if you can get a saw there.

If this is on the roof side of the deal, where water piles up, you might need to build a little peak between the roof and the chimney, so the water does not rush to the chimney down the roof. Kinda major rebuilding to tie that little peak into the roof, but it works.

Some 'different thinking' like that to get it done. Any type of goo you seem to need to redo every 3 years or so, with the heat & cold of a chimney, just doesn't last.

--->Paul

nodak3 · #6 10/31/10, 03:55 PM

Saw the title and thought old Santa was being naughty, not nice.

Just visualize--flashing around the chimney.

TNHermit · #7 10/31/10, 04:42 PM

The chimney not only has to be flashed it has to be counter flashed. As was stated above you need to run the flashing up to the chimney. Turn it up. Then you saw a kerf into the chimney maybe a 1/2 inch deep. Bend a piece of flashing so it will stick in the kerf and then bend it down over the other flashing. I like to roll up little pieces of flashing and tap them in the kerf to hold the counter flash in. then caulk it.

Check all mortar joints for cracks and loose mortar. Rain can run down inside them. It would also help if you out a cap on the chimney.

tiogacounty · #8 10/31/10, 04:57 PM

Quote:

Originally Posted by rambler

Masonary saw & cutting a groove for the flashing will cure it if done right, if you can get a saw there.

--->Paul

This is the way it's been done for a few hundred years now. Flash, then a counter-flashing tucked into a groove in the masonary. Back in the day it was secured by little sheets of lead, rolled up and stuffed into the joist above the flashing, then the joist was mortared shut. A proper flashing and counter-flashing installation will be leak free and durable for the life of the roof. Trying to caulk sheet metal to rock and hoping that it sticks is peein' in the wind.

Beeman · #9 10/31/10, 06:32 PM

As others have said cut a groove in the stone. Not hard with the right tools. Sticking flashing doesn't work, but that's how most do it.

http://www.chimneyflashing.info/Ston...-Flashing.html
Here's a link with some pics.

meanwhile · #10 11/01/10, 07:19 AM

Thanks everyone -
The chimney does have a cap on it. Three in fact since there are Three holes that come out. Wonder if the larger cap is running water off and onto the sides......hummmm....I will have to look at that.......

The Stonemason claims that he cannot cut into the stone since it is very large thick stones and the chimney is tall and old. Also, I don't trust him to do it.

The Roofer did try to use the softer flashing but said the stone still sticks out so much that the flashing will not press around it. Also he says the caulk will not stick to the stone and cement.

Would it work to:
-remove the metal flashing
-use that sticky wide tape like stuff, I think it is called Ice Shield (someone above mentioned it), and put it over the sides of the chimney
-put the metal flashing back over it to cover up the ugly Ice Shield?

OR how would I try to cut into the stone? If the Roofer says he cannot do it, how would I do it myself? What saw? Blade?

Thank you.

meanwhile · #11 11/01/10, 07:25 AM

Beeman - I looked at the photos and those are great but my chimney does not have the cement block showing? It only has the stone. It looks very much like the chimney in the photos but larger. The Stonemason (who was out here for something else) did repair loose mortar at the top but he was not happy to be up there plus he said he did not know how to fix the leak!

The Roofer has tried but he claims no one can cut into the stone.

Someone above said cutting the groove is the only way.....so maybe I better keep trying to find someone who can cut into the stone? Thank you.

fishhead · #12 11/01/10, 08:36 AM

Somehow you will need to divert the water running down the roof around the chimney.

Something like Rambler suggested should work. It wouldn't have to be tall.