USG Boral Gypsum Board Wet Stop 12.5 mm and 15 mm Wetstop Moisture Resistant is a factory produced, asbestos free, 1200 mm, 1220 mm wide panel composed of a noncombustible gypsum core is encased in a heavy natural-finish paper on the face side and a strong liner paper on the back side. The moisture resistance of the gypsum core is increased by adjunction of specific additives that ensures a higher resistance to water penetration. The face paper is folded around the long edges to reinforce and protect the core, the ends are square cut and finished smooth. Long edges of panels are recessed (tapered) allowing joints to be reinforced and concealed with a joint treatment. USG Boral recommend to use Sheetrock® All Purpose Joint Compounds for joint treatments and skim coating.