 What it does, it'll keep it on top so it's not absorbing. When it goes down inside the brick, it's pushing out the minerals and the salts out of the masonry. It's called efflorescence. And that's what that white powder is. That's all it is, is just salts and minerals that's being pushed out of the masonry. But if you seal it and you don't allow water down in the masonry product, you won't have that problem.