US Gypsum 163841-RDC06 Structo-Lite Gypsum Basecoat Plaster, 50 lbStructo Lite Basecoat is a mill mixed perlite aggregate gypsum plaster. It requires only the addition of water at the jobsite. Structo Lite Basecoat is USGs lightest weight and most highly insulated plaster. Structo Lite Basecoat provides a plastic working material that will conform to various designs and help achieve durability in walls and ceilings. It can be applied by hand or machine methods, on gypsum or metal lath, clay tile, concrete or cinder