Crown Molding - Plastic Crown Moulding Manufactured with a Dense Architectural Polyurethane Compound. CM-1189 Crown Molding. (9) Price : $23.99 per Molding Length Per Molding: 94 1/2" Breadth : 4-3/8" Height: 4" Width: 2" CROWN MOLDING is manufactured with a dense architectural polyurethane compound (not Styrofoam). Polyurethane is durable and 100% waterproof. The material can be sanded to shape just like wood. A MAJOR ADVANTAGE of polyurethane is that it is safe to install in rooms with the presence of moisture like bathrooms and kitchens. This product will not encourage the growth of mold or mildew. INSTALLATION is simplified with the use of modern adhesives. Small finish nails are used to secure the molding while the adhesives set. See below for installation instructions. THIS MOLDING is delivered pre-primed for most paints. Always test your paint on a small section to make sure there are no compatibility issues with the paint and primer. Most home latex paints work great on our molding.