On Feb 11, 8:37*pm, "__ Bøb __" wrote:
I have a double-flue chimney that has a leaky cap. * It gets saturated
with water, then drips down into the wall cavity. * I don't think it has
yet caused any real rot (hope not anyway) but I need to seal it from the
elements. * I tried cleaning it with bleach/Jomax .. let it dry
thoroughly, then gave it 2 coats of RustOleum's epoxy-based concrete
paint. * It held for about a year, but it is now coming off in big
flakes & pieces. * What type of material is best to seal this porous
surface ?? ?? * I thought about the paint they use on mobile home roofs,
but am looking for opinions. * How about that rubber membrane they use
in shower-pans ?? ?? * Just thinking out loud .. .. .. any
ideas/thoughts would be much appreciated.

I'm a little confused by your question, but I THINK I might
understand..

Some 15 years ago, I moved into a house that had a leakage problem,
basically from the chimney. Went through a lot of "experts" until I
finally found three different guys who all managed to agree on the
solution, sort of, even though they never met each other (at least
that I know).

Basically, told me to get a good chimney cap. I did (stainless steel,
etc.). Told me to build big fires when there was a lot of rain -- I
don't really do this but it was a good idea.

Finally, all told me to use Tamms Chemstop each August before the
rainy season. Ever since I followed their advice, I have had no
problems. Tamms changed their formula a few years ago, and it scared
me, but it still seems to work fine.

Anyway, I have to buy it at a Masonary supply outfit, and it goes for
$25 a gallon, but it only takes about half-a-gallon each August, so,
it's about $12.50 a year....even though the jug says not to keep it
that long, I do and it still works.

Anyway, try some Tamms, only problem you have to apply it when it is
dry and going to be dry for a few days....

Here's a webpage with some information -- use the Heavy Duty for
chimney's:

http://www.weberstone.com/chemstwb.pdf