ChimneyRx 300014 Brushable Chimney Crown Repair – Elastomeric & Waterproof Coating for Crowns & Masonry - Fast-Setting & Long-Lasting Protection Crack & Leak Prevention - 2 Gallon

Easy application. Cures quickly and makes a solid continuous seal along the cap. First coat paints on like paint to ensure all cracks and crevices are filled. Short time later it tacks up to allow for a heavier finish coat. I actually put 3 coats on my chimney cap and still had product left over. If it holds up well this would be a very recommended product.

This product worked to perfection! The crown of our chimney was severely damaged by a earthquake three years ago and I didn't think to check the chimney for damage...until two months ago when the rains began pouring into the fireplace. After a thorough inspection and online research I decided on CHIMNEYRX...and it was fabulous. Online purchase was easy...delivery on time...instructions clear and concise...and VERY helpful. Very easy to apply and when completed...looked like a pro. Things I did that might be helpful to others...dip your brush in water and shake excess water before applying material...makes for much smoother application and fewer brush strokes. If product begins to dry upon application...it was nearly 90 degrees and dry when I applied...spray your brush with water spritzer used to moisten chimney crown before applying product...again...makes for superior application with minimal brush strokes. Cleanup was very easy and materials are adhering like a fortress. Haven't had heavy rains to test it thoroughly, but I have NO doubt this product will be the answer to all my problems. To ensure a waterproof chimney, I also sprayed a masonry sealant on the bricks...easy to do and should last for years.

Went on easily, the stiff nature of the product meant it went on easier than paint, so no concern about it running or dripping, just didn't have that problem at all. I had a large and very rough chimney crown to seal so my coverage was much less than they advertise due to the roughness. Still, overall, the entire 1 gallon bucket covered what was about 18 square ft of crown with a bit left over. I might have used 3 quarts or so. The chimney was 56 years old and part of the roughness was from prior partial repairs so different parts degraded differently and there was much material to be removed. Still, the repair with this product was successful and it looks great. The next guy that has to use three ladders to go up and inspect the chimney crown in about 20 years will really admire my work!

My chimney sweep wanted $260 or so to seal the top of my chimney (Sept. 2020), so DIY saved around $200. Product arrived promptly, had clear instructions, went on easily, and dried quickly. Took about three hours to remove the old sealer, repair cracks in the concrete, and apply new sealer. Seems to be a durable finish. Be interested to see how long it actually lasts. EDIT: Almost six years later, I decided to climb up and see if I needed a reapplication after harsh NW PA winters and blazing hot summers. I had stored the bucket in my basement workshop. I checked the product, and it remixed easily. I checked my chimney cap, and except for a very few small areas that I peeled off, and some areas of slight cracking, it has held up remarkably well. I brushed a thick new layer on the spots I peeled and just touched up the cracks. It's good stuff. My 4-inch chip brush (which some people just throw away) cleaned up easily in a bucket of just plain water.

My chimney crown developed cracks that allowed moisture to saturate the bricks over the fireplace. The latest professional fix was annoying and expensive, so I bought this stuff and my son got up there and did the job this time. So far so good. In the past when I was able I'd gotten on the roof myself and filled the obvious cracks, but wasn't using the proper product and years later it had hardened and wasn't filling the cracks properly anymore. I called a professional. He did a good job that lasted 8 years, but at an outlandish price so I wasn't eager to call him again. The highly rated firm I called instead offered a better price (still $300), but had scheduling issues that dragged the effort out so long my ceiling got wet too and was in danger of falling in. Their first fix improved the problem but didn't fix it entirely so they had to come back and after 3 years the problem reappeared. After the bad experiences I was more interested in seeing if we couldn't do a better job ourselves. This product is very thick and grainy. It's cement colored so works well on the chimney crown. It doesn't drip so it's easy to control application. We used an inexpensive brush and just threw it out afterward to avoid messy cleanup. If such a product was used by the second professional, it was obvious it had been thinned which probably accounted for the short correction time. My son spent about 20 minutes applying this product which he said was easy, and after recent heavy rains, we can see the leaking has stopped. There is still more product in the container so I'll tape it closed to preserve it in case we need to use it again in the future. I'm very pleased with this product. It seems expensive, but is more than enough for a thick application on a large chimney cap and does the job. The directions say the chimney cap must be dry and it must be at least 45 degrees F (but not greater than 90) and remain so while the product cures (2-4 hours). We had to choose a good weather period when it wasn't too cold here, but that is far easier if you're doing the job yourself than waiting for a service appointment only to have it wet or cold that day so rescheduling is required.

I was very skeptical about doing this, however, I am very pleased now 2 years later at how much it has held up. I followed the directions to a T and prepped the service, cleaned it, roughed it up and then applied very very thick. I used the entire tub on the chimney. I am very pleased at the results as you can see from my before, after, and 2 years later photos. I posted photos of 2022(before application, lots of large cracks), 2022 (During application w/blue tape still on edges) and 2024 (2 years later, the rusting is from my rusting cap, which I need to remove, brush and repaint). I am just a homeowner that was impressed with a product that just worked, I have done so many projects that don’t work out. For now my cracks are still sealed and I can avoid having to put new concrete cap, this is firm but malleable and does the trick.

****UPDATE***** It’s been a18 months and no peeling, cracking, or bubbling! Keep in mind when using this product you should use a hard steel brush to remove all debris and make sure the surface area is DRY. The product cannot adhere to a moist surface and needs a minimum of 48 to 72 hours to cure and dry completely, less time If the weather is warm. This is a user friendly product. Wow- housewife? mother? single mother? business woman? daughter? I have a product for you!! Does your chimney need work? If your not afraid to get on your roof this is the best product DIY for you! Dust off the debris on the crown of your chimney, use a bottle of water to spray down the old cement crown, and apply this Brushable Chimney Repair right on.... I recommend using disposable gloves and bringing a small cardboard box or trash bag with you to wipe off and throw away any mess. Believe me though, this is the perfect consistency and it literally feels just icing a cake! I purchased a medium hard brush, and a 5.00 masonry tool to apply it, it started curing overnight. and as you can see it looks beautiful!!!

I'm impressed with this product! It goes on easily with a brush and putty knife--although a trowel might be easier in larger applications. Check out the online videos to find different techniques to try. A fine-spray mist bottle helps to keep things moist and workable, and for final smoothing. Taping edges helps to keep a more defined look, although I did pull the tape off while the coat was still moist and then smoothed the edge in with a wetted finger to taper and seal it in to the crevices in the brick. It looked a litle smeared up close--but hey--it's a chimney and looks fine from ground level! Clean-up is a breeze with water. I sprayed a light mist of water on the unused portion still in the bucket, then laid saranwrap over the bucket and fitted the lid back on to seal the remainder for future use. I give it a big "thumbs up". My 50 year old chimney crown is brand new now--and should be good for a long time. The light gray color looks fine, although it can be painted if desired. A little soot will darken it up naturally, anyway. Great stuff--and a good price, too!