# Any good brick chimney water repellents?



## quigleybmd (Sep 17, 2006)

I have a fairly large (3'deep x 5'wide x 3' high) brick chimney that absorbs water and leaks through the attic. It's a relatively new chimney (4 years), and in perfect condition, as is the crown. The roof was re-done 3 years ago, and has good copper flashing around the chimney. The roofer clued me in to the water coming in through the brick, by covering the whole chimney with a tarp during a heavy rain, while water was leaking in. Within about a 1/2 hour it stopped leaking, while it was still raining hard. So I sealed the brick with a product call Defy Masonry Chimney Water Repellent. That worked well for about 3 years, but now it's leaking again. Does anyone know of another product that would last longer? I've read to be careful about non-breathable types of products (like paints). How about Thompson's water sealant? Is it breathable? Also, the roofer suggested a crown that extends several inches beyond the chimney on all sides (it's currently flush, so water comes off the crown right down the brick). I'm not crazy after breaking up the existing crown or pouring a new one on top of the old, so I was thinking of something like either: a copper chimney chase cover over the existing crown extending well out, or piecing together thin slabs of bluestone or slate on top of the existing crown. Any thoughts? Thanks very much.


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## ShortEdged (Dec 23, 2007)

If you have determined that there is no structure issue:
Thompson water seal is crap, do not used it.
There is a vulcanized rubber product that last 20 years plus. It might darken up the brick a little, but it is good stuff. Its base is like mineral sprits so you have to keep it off the shingles.
“Lifetime Sealant”
Contact:
Ron Cavner
112 N Monroe St
Rockford, MI 49341 U.S.A.
www.CoatingsInternational.com
Info @ CoatingsInternational.com
616-863-6529 ••• 888-841-8180 ••• Fax 616-863-1076

I used it last year. For best results you will need to clean the old crap off as good as you can. You also need repair any mortar damage.


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## AaronB (Jan 29, 2005)

Whatever you use, be sure that it is a breather... mortar has to breathe.


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## [email protected] (Nov 17, 2008)

Depending on the size of the chimney, a copper chimney cap on the wash like the one shown here http://www.chimneyflashing.info/Copper-Chimney-Wash-Cap-Flashing.html might be easier to install than the stone slab. With 20oz copper you can extend the drip edge out so the water drips away from the bricks.


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