I purchased this product due to the cracks in my chimney cap. I must say that it surprised me as to how thick the product was when opening the container, and how quickly it dried. I did caulk first a week before, and caulked again just before brushing on this product with a large brush. The product goes on nicely and I was pleasantly surprised that it fit my entire cap for a double chimney, with two coats. I'll be watching this winter to see if I notice any leaks anymore on the interior brick of my fireplace. There were many before I started this project.