On Wed, 5 Sep 2007 03:13:28 -0500, "DanG" wrote:

Why are you sealing brick? Normally, it is meant to breathe. It
would not ever be considered a water proof surface.

Describe your problem. Maybe someone can help.

Here is my therory:

I have a chimney attached to the side of the house. Living on the wet
coast of BC, we get copious amounts of rain. The chimney above the
roof is fully exposed. It absorbs moisture and the moisture works
its way down the chimney. A significant amount of moisture presents
on the portion of the chimney located below the roof. This area
below the roof, being leaward, does not receive rain.

My concern is if moisture shows on the lower portion of the roof, it
will also get into the wood structure and cause rot. Notwithstanding,
no rot was seen when the roof was re-shingled three years ago. During
the shingling process I made sure the flashing was correct (which
endeared me to the roofers .

In the past I have used Thompson's sealer which works for about two
years. There are hairline cracks in the mortar above the roof and my
belief is the Thompson's is sealing the cracks.

Im looking for a sealer which will be of a higher quality and
durability. A silicone base perhaps?

Hope this makes sense

Gary