Moisture Resistant gypsum plasterboards, also known as Water Resistant wallboards or Green wallboards in North American markets, generally have the following features:
gypsum core is specially treated with water resistant chemicals that retard the ingress of moisture and water
special paper liners in light green or light blue colour, treated with water resistant chemicals, embrace the front and back faces and long edges of the boards
long edges are recessed / tapered or square
designed to suit non fire-rated internal drywall partition and ceiling systems in intermittent wet areas as well as screwed-up concealed grid external ceiling systems that are not directly exposed to sun lights and rains
Developed countries have their own national standards regulating the production and testing of physical and mechanical properties of gypsum plasterboards. Nevertheless, all norms related to gypsum plasterboards are rooted in American standard ASTM C1396. British standard BS 1230 and Australian / New Zealand standard AS-NZS 2588 are very similar to ASTM C1396, slightly differ in the measuring unit of dimensions as below:
