How much does it cost?
Stock primed pine crown molding starts at about $1.50 per linear foot, plaster at about $5, foam at about $3.75, and flexible polyurethane at about $1.
Stock or custom?
Stock profiles are the least expensive and most readily available. Custom work—matching an existing profile or creating a new design—can cost more than twice as much and take up to six weeks to produce.
DIY or hire a pro?
Installing a one-piece crown is a project most detail-minded homeowners can handle. But if a room has out-of-square or curved walls, or if the molding is made of heavy plaster or built-up wood profiles, hire a pro.
How much to buy?
Measure the perimeter of the room, then add 10 to 15 percent for waste; for rooms with lots of corners, add 20 percent.