Plaster Tasks: Applies coats of plaster to interior walls, ceilings, and partitions of buildings, to produce finished surface, according to blueprints, architect's drawings, or oral instructions, using hand tools and portable power tools: Directs workers to mix plaster to desired consistency and to erect scaffolds. Physically, plasterers and fireproofers must be able to: Climb and maintain balance on scaffolds and ladders, reach for, handle, and manipulate objects and materials, lift and carry objects weighing up to 50 pounds, stoop, kneel, crouch, and crawl.