We had a beautiful flagstone patio laid in concrete in 2006. We wish we had been told to put a water repellant on it. We have a lot of spalling or water erosion on the flagstone, in addition to algae stains which are easy to clean. We would like to apply Siloxane on it, but would like to know if there is a way to sand or smooth out the flagstone first to give it that "just laid" appearance. I would appreciate any advice you can give me.
Thank you. Susan Wright