I've removed the old popcorn style texture from my ceilings and was left with the "white powder" left behind from the old texture. I found that if all the white powder was not completly removed, the new texture would not stick to those areas. Use TSP (trisodiunphoshate) to those areas and you should get rid of the old powder. Read the directions on the package for strenth. Home Depot carries it in their paint department.