Is there any guideline on how much of the expansive foam to use? I have a
chimney and where it meets the concrete roof tiles the gap is too large for
caulk or sealant. As a matter of fact I can fit two fingers along one edge
and there is a small crevice under the tiles as well where they meet. Even
though I am pretty sure there is flashing underneath I will still feel
better if I can fill the crevice along the perimeter.

I thought I would use those foam that expands, however last time I used it I
did a poor job of it and underestimated how much to use and it ended up
expanding and cracking the surface I put on top of it. I wonder what is the
best way to gauge how much to apply.

Thanks,

MC

On Jul 9, 2:29 am, "MiamiCuse" wrote:
Is there any guideline on how much of the expansive foam to use? I have a
chimney and where it meets the concrete roof tiles the gap is too large for
caulk or sealant. As a matter of fact I can fit two fingers along one edge
and there is a small crevice under the tiles as well where they meet. Even
though I am pretty sure there is flashing underneath I will still feel
better if I can fill the crevice along the perimeter.

I thought I would use those foam that expands, however last time I used it I
did a poor job of it and underestimated how much to use and it ended up
expanding and cracking the surface I put on top of it. I wonder what is the
best way to gauge how much to apply.

Thanks,

MC

You could try and use some backer rod. This is a foam which is tube
shaped and available on a roll. You stuff this into your gap first.
Then fill up the remaining bit with caulk.

You can get this stuff at Home depot.


http://www.rd.com/content/openConten...ontentId=19689

Best, Mike.

"MiamiCuse" wrote in
:

Is there any guideline on how much of the expansive foam to use? I
have a chimney and where it meets the concrete roof tiles the gap is
too large for caulk or sealant. As a matter of fact I can fit two
fingers along one edge and there is a small crevice under the tiles as
well where they meet. Even though I am pretty sure there is flashing
underneath I will still feel better if I can fill the crevice along
the perimeter.

I thought I would use those foam that expands, however last time I
used it I did a poor job of it and underestimated how much to use and
it ended up expanding and cracking the surface I put on top of it. I
wonder what is the best way to gauge how much to apply.

Thanks,

MC




As Ransley said, flashing is the right way to do it. Here's an article on
the way it should be done.

http://www.rd.com/content/printConte...ontentId=17758

I've yet to fix a leaking chimney that was done this way but maybe that's
why they leaked, ya think? Ones I've done this way never leaked. Yep it
requires time, work & tools.

On Mon, 9 Jul 2007 02:29:27 -0400, "MiamiCuse"
wrote:

Even though I am pretty sure there is flashing underneath I will still feel
better if I can fill the crevice along the perimeter.

Foam is not needed, imo. You are doing something cosmetic - I guess.
The UV rays will eventually damage the foam...will it last.

Flashing underneath, sounds like my Spanish type tile. Barely nailed
on :-))

Fix the flashing if need be, but my guess is the roofer never used
foam... any area house...

--
Oren

"The voices in my head may not be real, but they have some good ideas!"