We were beginning to get some water intrusion through the chimney brick into the living room fireplace. The chimney crown needed replaced due sever cracks and poor condition. After the new crown (top) was poured in placed and cured I wanted to use a good sealer to protect from water penetration. After extensive research I determined the Silane Siloxane based Foundation Armor 5000 WB was the best value for my dollar. I purchased two gallons based on the coverage recommendation and used a pump sprayer to apply the product. Oh, I did reach out to Foundation Armor with a question about applying a second coat and received a prompt response. I'm very satisficed with the product and the 7 - 10 life of the product was a big selling point for me.