 Okay, and so if I use the same brand, it should be okay to go over the existing semi-transparent with the new... You don't even have to stay with the same brand. You know, you can use a different brand as long as you properly prepare the deck before you make that application. So if there's any loose stain or loose fibers of the wood, you may have to do some sanding and some scrubbing. If you do pressure washing, that's okay, but make sure the deck is really, really dry.