How to Install Wood Trim & Moldings

Measure the area in which you'll add trim, using a measuring tape. Recruit a partner if the distance is too far to measure by yourself. Write the measurements down with a pencil and paper so you'll know how much trim you'll need. It will also help you as you begin cutting and installing the molding.

Paint or stain the wood trim and moldings, using a paintbrush. Finishing the moldings before installing them will save you a lot of time. It is easier to paint moldings while they are lying on sawhorses than it is to paint moldings next to the ceiling. Allow the paint or stain to dry before installation.

Cut the trim or moldings to size. Baseboards, window and door casings, and chair rails should be cut with the molding flat against the miter saw table. Crown moldings must be cut upside-down so that the top of the molding rests against the table of the miter saw and the bottom of the molding rests against the miter saw fence. The crown molding should look like it will look when it is installed, only upside-down. All types of molding corners can be cut by setting the miter at a 45-degree angle. Cut one side of the corner from a right 45-degree angle and the other side at a left 45-degree angle.

Hold the molding in place while you nail it to the wall with a pneumatic nail gun, enlisting a friend's help. Cut and install the pieces as you go.

Fill the nail holes in the molding with wood putty. Once the putty is dry, touch up the paint or stain.

Caulk large gaps between the wall and the moldings. Apply a small bead of caulk and use your finger to smooth it out. Let the caulk dry completely.