MasonryDefender Chimney Crown Sealer - Brushable Waterproof Sealant Prevents Leaks - 1/2 Gallon

My chimney used to leak like it was emotionally unstable. Rainstorms? Cue the buckets. Snow? Instant anxiety. Then I found this crown sealer — thick, brushable, and clingy in a way that actually helps your relationship with your roof. It spreads on like frosting, fills every crack like it’s got a grudge against moisture, and dries into a rock-solid barrier that laughs in the face of rain, snow, sleet, and freeze-thaw drama. Application was surprisingly easy — just grab a brush and channel your inner Bob Ross. Took me less than an hour and I didn’t even have to Google “how to fix a chimney leak” afterward. Weeks later, storms rolled through and… nothing. Dry as a dad joke in the desert. If your chimney is crying for help, this is the therapy it needs — easy to apply, built to last, and tough enough to survive whatever the sky throws at it.

While long term results can't be guaranteed, initial impressions are very good. As long as you prepare the surface correctly, this stuff will stick well. One negative review I saw showed the product had been applied to a very dirty surface. Just like painting, surface prep is one of the most important steps in the process. As well as a chimney cap, it was applied to the top of a small retaining wall along our driveway and looks a lot better than bare concrete.

Easy application and great value.

Fixed it well and seems to be no more leak or moisture damage seen 🤔.

Easy to apply and filled in any cracks showing. Excellent product! Made the cap look like new.

Works great looks nice

Worked well, it has a consistency similar to peanut-butter. Let it dry between coats. Effective to use duct tape to mark off above and below, then peel off the duct tape once dry for a nice clean line. I used 3 coats. For cracks, I used latex caulk, and was able to paint this on right over top of the caulk, no worries. I am happy that I used 3 large moving blankets that I taped to the chimney and draped underneath, as that caught a few drops and splashes. This is latex, so make sure you use in conjunction with genuine latex caulk, don't second guess the instructions and go silicone.

I did not realize how bad a shape my chimney crown was until I was able to get view from the top down. There were small chunks and cracks on the top that I could not see from looking up. The product is thick when applying, just get a couple of good paint brushes and take your time. It's a good idea to tape off the bottom and other areas if you want a clean, professional look. Highly recommended for do-it-yourselves.