Crown moldings, also called sprung cove moldings, are the decorative trims used to cover the seam where ceiling and wall meet in a room or other kind of structure. There are a variety of styles and designs to choose from, but whether the molding is plain or elaborate, cutting crown molding can be a bit tricky. This is largely because the shape of crown molding is somewhat cumbersome and because precise cuts are necessary to a proper final product. With the right tools and some planning however, properly cutting crown molding can be done!
Many different types of saws can be used to cut crown molding but a miter saw is probably the best and easiest way to cut the molding correctly. You can either use a power miter saw or a hand miter box. When choosing your saw, you should consider the width of your molding to determine whether your saw will be able to extend beyond the width of the molding. Note, however, that when turned to a 45-degree angle, the maximum molding width that can be accommodated is shortened considerably.
The first rule to follow in cutting crown molding is to measure the wall as precisely as possible and then measure the molding pieces just as carefully. There's nothing worse than cutting crown molding just a little too short. Because you can’t lengthen the molding after cutting it too short, it’s generally better to err on the side of cutting the molding too long and then slowly shaving off some of the length to create the perfect fit.
The next important thing to do when cutting crown molding is to properly set the molding against the saw. The wall side edge of the molding should be firmly pressed against the back fence of the saw and the ceiling side edge of the crown molding should be set against the saw base. Not having the molding properly fitted to the saw can result in cuts that are not properly aligned. Having someone help you hold the molding can help ensure that you have the molding correctly set against the saw.
Next, you should make careful, straight cuts, making sure that the molding remains seated against the saw's fence throughout the process. For corners, the ends should be cut at opposite 45-degree angles so that the pieces properly fit together. Sometimes drawing out the cuts and visualizing how the molding will fit into place will help prevent you from cutting crown molding in the wrong direction or on the wrong end.
Whenever possible, the length of crown molding should cover the entire length of the wall in one piece. If your wall is too long, this may not be possible either because molding strips aren’t sold in such long pieces or because trying to manage such long pieces will be too unwieldy. If this is the case, you can use more than one piece of molding to line a wall. While there are many ways to create the joint between two pieces of molding along one wall, the scarf joint, where the two pieces are aligned at 45-degree angles, is generally preferred because it is better at hiding the glue line between the two pieces.
Once you are done cutting the crown molding you can start installing your pieces. Simple crown molding is fastened in place with tiny nails and glued together at the joints. More complicated crown molding designs may be comprised of multiple pieces attached to a square nailing strip that fits into the seam where the ceiling and wall meet. You can drill pilot holes into the molding if splitting is a potential problem. Finish nails can then be used to nail the pieces into the wall studs.
Before you start cutting crown molding you may want to get some scrap molding to practice your cutting techniques. You can also visit your local home improvement store to see if they offer any clinics on the practice.