So far so good. I had some small drip leaks around screws on my patio roof. Used through the roof to seal around each screw and around the edges. I'm in Florida and we get very strong afternoon thunderstorms. The area's I sealed are no longer leaking. Plan to purchase more and seal the rest. It's been about 3 weeks now since applied, hopefully this will last longer than traditional caulk. Very happy at this time!

This stuff works great used where my porch meets my trailer and no leak at all and ive had a leak there for quite a while and was trying to fix it seems this stuff dod the job had a hard rain yesterday and no a drop from where i used this great product would totally recommend

This stuff is the best I have found yet..
Make sure you can leave a window open for a couple days..
Other than that it stops leaks on the spot.
I had to put some on from inside the house first.
That's why I had to open the window. And it stopped leaking. So I know it will work on top of the roof too.

I used this product on my RV just this week. I did a first patch coat 4 days ago, and then a second coat last night. It rained this morning, and the product has worked flawlessly. Some of the cracks on the roof line were around 3/8ths of an inch wide. Yet Sashco flowed into and filled even that wide of a gap. I used the product on every crack and seam of the roof, and over all the previous patch material placed before. The worst spot was where my air conditioner sat on its pan. I did that yesterday. There was as much as 3/4ths of an inch gap below the pan. I stuffed that with Oakum, and then heavily slopped Sashco onto the roof/pan border, and pushed the mix into the Oakum and against the 1 inch lip of the pan. I put it on so thick that it likely will not set up for over a week. Around 12 hours later it started raining. The entire patch job has held, and amazingly the heavy use around the air conditioner pan has held, even when the pooling water reached over half way up the one inch lip of the pan. I had to throw several sheets on the roof to form a siphon to drain the pool around the air conditioner. Next year I will have to fix the sag on the roof. This product does everything it claims to do.

Great product. Very easy to use. I had cracks in my decking on the balcony built above my laundry room. I used this to seal it. It appears to be a very good, solid seal and seems to be a product that will have very good wear. Of course, only the rainy season this fall will tell for sure, but I feel good about this!