This product worked great! I recently took a look at the condition two years after application and I am very impressed.My chimney crown was in terrible condition, it was a spider web of cracks that the previous homeowner had tried to repair with caulking that had long since dried out. I wanted to repair the chimney crown before winter but I had waited until late fall, so forming a new concrete crown was out of the question, not to mention out of my skill set. I read about this product and thought it was worth a try. I read the directions and used a large brush and painters tape to get nice lines. I didn’t prep the surface other than brushing off the area with a hand brush and scraping off some moss. The application took 30-45 minutes and I applied it in 40 degree weather. I only applied a single, thick coat, but it has held up very well. I’m most pleased with the fact that it was able to adhere to the caulking, concrete, brick, and ceramic flue materials and not crack over 2 years of all those different materials heating/cooling at different rates. I am also pleased with the look, I think the grey appearance is much better than the tar black appearance I have noted on other houses in my neighborhood. Very pleased that I took a chance on this product.