How to Install Chair Rail Molding

Chair rail molding does two jobs at once: it protects drywall from furniture impact and visually anchors a room by breaking the wall into two distinct zones. The bottom half of your wall suddenly feels grounded. Install it correctly and it looks built-in. Rush it and the gaps and crooked runs show immediately—this is one of those jobs where precision matters because everyone's eyes will land on it. The work is straightforward carpentry. You'll measure, find studs, cut molding, and secure it. Most rooms take a weekend morning. The main variables are wall condition—uneven plaster or drywall requires shimming—and corner handling, which demands patience but no special skill. This guide walks you through standard installation in a typical living room with drywall and square corners.

1. Level the Starting Line. Measure up 36 inches from the floor at multiple points around the room—at least one measurement every 6 feet—and mark with a light pencil line. Use a long level to make sure your line is truly level; uneven floors will throw off your eye otherwise. A laser level or chalk line works too if you have one, but a regular level and straightedge are fine.
2. Map Every Stud. Use a stud finder to locate wall studs along your marked line. Mark each stud center with a light vertical mark. Studs are usually 16 inches on center, but verify as you go. Mark stud locations on every wall, including around corners and windows—you'll need these reference points to plan your cuts and nail locations.
3. Cut for Tight Fit. Measure the wall length, subtract 1/16 inch for compression, and make your first cut. Use a miter saw for clean, square cuts. For most straight runs, cut simple 90-degree butt joints. At inside corners, you'll cope the molding (cut it to sit tightly against the adjacent piece); at outside corners, use 45-degree miter joints. Dry-fit each piece before nailing.
4. Nail the First Wall. Start on the wall you see first entering the room. Apply a thin bead of construction adhesive along the back of the molding, then position it on your pencil line. Drive finish nails or 2-inch brad nails through the molding into the studs—at least two nails per stud, one near the top and one near the bottom of the molding. Nail every 16 inches even between studs for extra hold. Set nails slightly below the surface with a nail set.
5. Perfect the Corners. Move to the next wall. At inside corners, the new molding butts against the previous piece—sand or plane the end square. At outside corners, cut both pieces at 45 degrees and miter them together. Apply adhesive, position, and nail in the same pattern. Check inside corners with a straightedge; small gaps are fine, but large ones signal an out-of-square corner and require shimming or coping.
6. Fit Around Openings. Where chair rail meets a window or door frame, cut the molding to fit tightly against the frame. Miter or butt the cuts depending on the angle. If the frame juts out from the wall, you may need to notch or cope the molding to sit flush. Secure the same way as wall runs—nails into studs where possible, adhesive between.
7. Seal and Paint. Use paintable caulk to fill the gap between molding and wall. Also fill nail holes with wood filler or putty matching your molding finish. Let everything dry, then sand lightly with 120-grit paper. Paint or stain the molding to match your wall color or leave it natural. Two coats usually covers.