How to Replace a Section of Damaged Baseboard or Trim

Baseboard and trim take the everyday abuse of a home, and a damaged section can make a whole room look tired. Replacing a piece is a satisfying job with a handful of hand tools and a little patience at the corners.

Get the old piece out cleanly

1. Score the paint line. Run a utility knife along the top edge where the baseboard meets the wall, and at any caulk line. This keeps you from peeling paint off the wall when the trim comes away.
2. Pry gently. Work a putty knife, then a small pry bar, behind the baseboard, using a wide scrap of wood against the wall so you spread the pressure and don't dent the drywall. Ease along the length rather than yanking one spot.
3. Pull the nails through the back. Rather than hammering nails out the front (which splinters the face), grip them from the back with pliers and pull them through. Saves the piece if you want to reuse it as a pattern.

Measure, cut, and fit

1. Measure the gap and, better yet, use the old piece as a pattern for length. Mark with a V and a square.
2. Cut square ends for a butt joint where the trim meets a door casing or another straight end. A miter saw or a miter box and hand saw both work.
3. Handle the corners. Outside corners (that stick out) get two 45-degree miters that meet. Inside corners are traditionally "coped" for a tight fit, but for a homeowner, a 45-degree miter or a square butt with caulk is perfectly acceptable and much easier.
4. Test-fit before you nail. Dry-fit the piece and shave or re-cut as needed. Trim is forgiving if you sneak up on the fit.

Nail, fill, and finish

1. Nail into the studs and the bottom plate. Finish nails at a slight angle hold well. A nail set sinks the heads just below the surface.
2. Fill the nail holes with wood filler, let it dry, and sand flush.
3. Caulk the top and the joints. A thin bead of paintable caulk where the trim meets the wall and at the corners hides small gaps and gives that clean, finished line. Tool it with a wet fingertip.
4. Prime bare wood, then paint. Two coats for a durable finish that matches the rest of the run.

Know when to call a pro

Swapping trim is great DIY. Call for a hand when the baseboard is water-damaged or swollen and you don't know the moisture source (fix the leak first, or it happens again), when there's soft or rotted wall or subfloor behind it, or when you want a whole-home trim package done crisp and consistent. Damaged trim near a bathroom or exterior wall can be the visible edge of a water problem worth checking.