ChimneySaver FlashSeal Elastomeric Roof Chimney Flashing Sealant - Waterproof, Flexible Seal - 1 Gallon (White)

We had a leak on the outside wall of our work shop. We tried just about everything and nothing stopped the leaks. This stuff is amazing. We got the wall sealed, no more rain water coming inside. Worth every penny

I ordered this product to repair a nagging chimney leak that I could not seem to remedy with roofing caulk. After the 3rd failure to fix the leak I ordered the Chimney Saver. After the first rain I didn’t encounter a single leak. Although time will tell the whole story I am so far impressed with this product. It was easy enough to apply and very easy to clean up. I bought the Flash Seal reinforcement mesh that is recommended with this product which also helped to create a nice thick layer around the bottom of the chimney. I used duct tape to make a clean application line around the base which worked like a champ. I had some left over so I sealed the top part of the chimney where the mortar was starting to crack. This stuff is a little pricey but it does the job. Saving the expense of calling a roofer was well worth it. Update: The Dallas area that I live in just got hit with a terrible storm that produced extremely high winds and copious amounts of rain. I am happy to report that the repair job on my chimney held up beautifully. Not one drop of water made it through. I now have to say that this product is battle tested, tried and true. This storm was one of the worst that I can remember in several decades so I would gladly tack on some more stars if I could.

This stuff works great!

11/5 stars, this stuff saved me close to 1100 dollars in roofing repair. So, my situation: My house is nearly 150 years old with a steel roof of indeterminable age. Spoiler alert, it leaks. Particularly bad was the flashing around the chimney, which was "sealed" with sheet steel, mortar, and dreams. It leaked like a sieve. In addition to a few other repairs I needed (rusted out roof bolts, seam leaks where roof meets exterior wall, etc), roofers and chimney specialists quoted me between 1100 and 1800 to stop all the leaks. I asked them what products they'd be using, and they all said "FlashSeal and mesh". Being the cheapskate, DIY nerd that I am, I googled it. Any moron can apply this stuff. I cleared the old flashing, pressure-washed the contact areas, and painted the stuff on. Done in less than an hour. So then I looked at my remaining 9/10ths of a bucket of Flash Seal, and got a little crazy. I put down FlashSeal, Mesh, and more FlashSeal anywhere that even *looked* like it *might* be the source of a leak. It's been two weeks, and I have not been able to locate a single continued source of leaks. So far, so good. I will update in a year to see if the stuff has withstood the test of time. For those curious, the installation goes thusly: Clear the contact surfaces thoroughly. I used a pressure washer, windex, and a towel. Apply a generous coat of FlashSeal. Let it get a little sticky. Apply a layer of FlashSeal reinforcement mesh, covering the gaps you're looking to seal. If it's on an angle, start from the bottom and layer the mesh such that the 'higher' part that overlaps is on top. Apply a generous coat of FlashSeal on top of the mesh. Keep applying until the mesh is coated into a single, continuous surface without any holes. Wait 45 minutes, repeat. Keep doing that until you are confident that nothing can get through.

This review is from someone who is average in the expertise department. Not a master builder. For those odd cases when you cannot apply step flashing and counter-flashing, this type of product is a good candidate for a plan B. It is easier to apply than step+counter flashing because you don't need a metal brake and you don't need to cut a kerf into the chimney brick. However, I wouldn't substitute this on a chimney where it is possible to do the flashing (aka plan A). So, knowing that, you decide plan B is your best approach and find FlashSeal... This is like a paint-on caulk with particles suspended in it that are "quartz" (didn't that stuff used to be called by a different name?). I wouldn't use it without fiberglass reinforcement tape. It works much like stucco repair in that you lay down a scratch coat of FlexSeal, embed the fiberglass tape, then coat it with a second layer of FlexSeal. Here's my impressions from using it. The types of jobs where this product is chosen are usually too rough to be strict with the thickness recommendations given on the product. I had to error on the thicker-than-recommended side in order to get all defects sealed. That also means the coverage estimates are referring to ideal settings. Don't expect to get the published coverage. Some things I learned when applying are that foam brushes, at least the ones I found, did not work. A cheap bristle brush worked better. Also, after applying the fiberglass, brushing towards the creases/angles/bends when applying the second coat of FlexSeal helped keep the fiberglass in the crease instead of stretching it away so that you have to push it back into the goop. It was also difficult to work fast enough to make sure it doesn't dry before finished, so plan everything before starting. If there were a slightly longer dry time, more realistic coverage estimates for the typical rough repair situation, and more ingredient details (quartz?), then it would easily earn 5-stars.

Excellent sealant specifically formulated for chimney flashing repair. I had a small seeping leak of rain drops going along the chimney inside the attic. Wasn't a big deal, but I didn't want to take any chances. I highly recommend this to mend your chimney flashing woes rather than spending thousands on roofing experts. For less than $100 you can do it yourself and be proud of a great job! The application is easy with a standard wide 3" paint brush and goes on like frosting on a cake. Rather easy to use and seals nicely. I highly recommend using the reinforcement fabric to make your seal nice and tight. I was going to go the cheap route and buy some standard drywall seam tape, but it wasn't wide enough for my application. I bought the brown color because my roof is tan/brown and it blends right in like camouflage perfectly! I'm glad to have found this product here, as it can't be purchased anywhere at local big box hardware stores. I'm waiting to see it dry and test it with the next large rain storm to see if it works. This product could also be used around roof vent-pipes or around skylights from what I read.

Excellent!! Works!!

We had three leaks where our chimney met the roof line. Applied as directed and all three cracks/leaks are sealed. Using the fiberglass mesh tape is the way to go. Really makes the product stronger and I think will last for years. Oh yes, working from top to bottom helps seal everything and it bonded to both flashing and the brick.

Easy to install and creates a great seal.

the product came already hard in packaging and could not use this... was ready to fix roof then had to run and find a different product