Tips for Miter Joints in Crown Molding

Set It Right

• Positioning crown molding can be one of the most difficult parts of making miter joints. Instead of laying the molding flat on the miter saw table, you need to position it in place. Incorrectly positioned molding will lead to gaps and other problems with your miter joints. Set the crown molding upside-down on the miter saw. Position the molding on the saw so that the top of the molding sits against the miter saw fence and the bottom of the molding rests against the miter saw table.

Cope Inside Corners

• How many times you try to miter cut crown molding for inside corners doesn't matter; you aren't likely to get it right because inside corners need to be mitered and then cut with a coping saw. The coping saw ensures that the two pieces of the corner fit together perfectly. Get perfect inside corners by cutting the first corner at a straight 90-degree angle. Cut the second corner at a 45-degree miter cut. Mark the leading edge or profile on the 45-degree angle cut. Hold a coping saw at an angle behind the marked leading edge. Cut away the back part of the molding with the coping saw. The coped molding should then fit directly into the profile of the first piece of molding.

Measure Twice

• One of the most common mitering mistakes isn't actually a mitering mistake, although many do-it-yourselfers think it is. Instead, this common mistake comes from not measuring correctly. If you don't measure your molding correctly, the mistake will show up in your miter cuts. Instead of meeting together like they are supposed to, the corners of the molding will have a gap between them. Easily correct this mistake by measuring for the molding twice. Ask a partner to help you measure the walls where the molding will be installed so you get the correct measurements.

Give Yourself a Break

• You will make mistakes in your miter cuts and can spend a lot of time and money correcting incorrectly cut moldings. However, you don't have to spend all of that time and energy to get good looking moldings. When you make mistakes in your miter cuts, install the molding anyway. Wood putty and caulk can fill almost any mistake that you make during the cutting process. Fill gaps and nail holes with the putty or caulk, and let it dry per manufacturer directions. Paint over the putty or caulk, and no one will ever know that you made a mistake.