You need to stain PT wood-It shouldn't slide around after that. I've stained a lot of barns and used a spray gun from Wal-Mart that worked great and stained quickly-got in areas a brush won't reach. You can get almost any color you want.It's PT wood, which is why I was wondering what kind, if a special kind, is needed to paint. I'm not worried about anything sliding around. In fact, I feel that it would make shoveling mulch easier with the smooth surface. I just don't want to mess up the PT wood by using the wrong type of paint.