I applied the product on a stamped concrete patio. After the first coat was on about 4 hours, we had an unexpected rain shower. It didn't appear to harm the surface, but on closer look before applying the 2nd coat, I noticed a few places were there were small opaque bubbles. I was going to call the company for advice, but instead used steel wool to lightly rub the bubbles, and it easily cleaned them from the surface. I applied the second coat about 2 days after the first and it completed the job nicely. Very satisfied with the application and the result. Since my stamped concrete has many grooves, I found applying the second coat with a 1/2 inch roller worked a little better than the first coat with a 3/8 inch roller. I would highly recommend the product for stamped concrete.