Chair rail moldings add a touch of class to any room. They are traditionally used in dining areas to protect the walls from bumps and scrapes dealt out by chairs as they are backed away from the table, but chair rail can add architectural detail to any room in your house. Don't let the thought of using a miter box or miter saw scare you off from installing a chair rail -- it's not as complicated as it seems.
Measure the height for your chair rail. A chair rail typically sits at one-third the height of the ceiling, or between 32 and 36 inches off the ground. Use your tape measure and a pencil to mark the height at multiple locations along the wall, then connect those points in a straight line.
Make sure your line is level. Once the line for your chair rail is marked, use a level to ensure that it is even along the wall. Make adjustments as necessary.
Paint or stain your chair rail if it is unfinished.
Measure your chair rail. You likely won't be able to use one piece to fit the whole wall and will have to put two pieces together.
Cut your chair rail. You will need a miter saw to get 45-degree angles. A miter saw is like a circular saw, but it can be rotated on a base with settings for precise angle cutting. The corners of your rail need to be at 45-degree angles to join at a 90-degree angle. Pieces that you have to join in a straight line will also be cut at 45 degree angles, with one piece angling in and one angling out.
Attach your chair rail to the wall with wood glue. Align the top edge of the rail to the line you marked on the wall.
Begin attaching the chair rail at an inside corner. Use a pneumatic nail gun to drive in nails to prevent splitting of the wood. Start placing nails in the center of the rail and move towards the edges. Work your way around the room until the chair rail is completed.
Cover nails with wood filler or nail putty along the length of the chair rail. Sand any excess filler or putty after it is dry.