Does anyone know if roof cement is compatible with PT wood? The wood is MCA (micronized copper azole) and the cement is Gardner Wet-R-Dri (all weather plastic roof cement). The cement spec. sheet doesn't state anything about PT wood, but does recomend it for a below ground waterproofer. Yes, I've contacted Gardner for an answer and haven't recieved a reply about this. So...who thinks using this tar-like substance on PT wood is OK? Thanks, JB Edit:- I'm thinking of building a waterslide also, for the nephews.