How do I replace a damaged baseboard?

Short answer

Replace a damaged baseboard by carefully removing the old piece, prepping the wall, cutting a matching replacement (coping or mitering corners), fastening it with finish nails or adhesive, then filling, caulking, and painting for a seamless finish.

What to expect

This is a manageable DIY for most homeowners with basic tools. The project typically takes 1–3 hours for a single wall or small room section. Material costs vary by profile and material, roughly $1–2/ft for primed MDF, $2–4/ft for primed wood, and $2–5/ft for PVC. If you own a miter saw and a brad nailer, your results will be cleaner and faster, but a miter box and hammer work too.

Tools and materials

• Tools:
  • Utility knife, putty knife, and a small pry bar
  • Oscillating multi-tool (helpful for cutting old nails or undercutting door casing)
  • Miter saw or miter box and back saw; coping saw (for inside corners)
  • Tape measure, pencil, combination square, level
  • Stud finder (with AC wire detection) and a finish nail set
  • 18-gauge brad nailer (or hammer) and air compressor, or cordless brad nailer
  • Caulk gun; sanding block (120–180 grit)
  • Vacuum and painter’s tape
• Materials:
  • Replacement baseboard (match the existing profile and height)
  • Finish nails or brads; wood glue for joints; construction adhesive (optional)
  • Paintable latex caulk (preferably siliconized)
  • Wood filler or spackling compound; primer and paint
  • Quarter round or shoe molding (optional to cover floor gaps)

Typical specs:
- Baseboard height: 3 1/4"–5 1/4" in most homes
- Fasteners: 18ga brads, 1 1/2"–2" into studs; 15/16ga 2" for thicker profiles
- Corner cuts: 45° miters for outside corners; cope inside corners for tighter joints
- Scarf joint: 30°–45° overlap on a stud with wood glue

Safety first

• Wear eye protection and a dust mask. Gloves help when prying.
• Pre-1978 paint may contain lead. Avoid sanding, minimize dust, and consider lead-safe practices or a pro.
• Use a stud finder with electrical detection to avoid driving nails near hidden wires. Be cautious near baseboard heaters and plumbing runs.

Step-by-step: Removing and replacing a baseboard

1. Score and loosen:

   • Run a utility knife along the top caulk line and at door casings to break the paint/caulk bond.
   • Slide a putty knife behind the baseboard to protect the wall, then use a small pry bar to gently lift it off. Work from one end, moving a few inches at a time.
   • If the board won’t release cleanly, use an oscillating multi-tool to cut stubborn nails at studs.

2. Prep the wall and area:

   • Pull or cut any protruding nails. Scrape away old caulk and adhesive. Patch torn drywall paper with a thin layer of spackle and let dry.
   • Vacuum debris. Check for moisture damage—fix leaks before installing new trim.

3. Select material and pre-finish (recommended):

   • Match profile and height to adjacent trim. MDF is smooth and affordable for dry rooms; PVC works well in baths; primed wood is durable and paints nicely.
   • Lightly sand and apply primer/first coat of paint before install. Back-prime ends if the area is humid to reduce swelling.

4. Measure and plan joints:

   • Measure wall length. For walls longer than a single stick, plan a scarf joint centered over a stud with a 30°–45° overlap and wood glue.
   • Decide on corner strategy:
     • Inside corners: Cope one board against a square-cut board for the tightest joint, especially with uneven walls.
     • Outside corners: 45° miters with a tiny back-bevel; glue and pin both sides.

5. Cut the pieces:

   • Cut square at door casings with a 1/16" reveal from the casing face for a shadow line.
   • For coping: cut a 45° miter first to expose the profile, then follow the profile with a coping saw; back-cut slightly for a tight fit.
   • Dry-fit each piece and fine-tune as needed.

6. Install:

   • Locate studs and lightly mark the wall or blue tape above the installation line.
   • Optionally apply small dots of construction adhesive to the back (helpful on wavy walls).
   • Hold the baseboard tight to the floor or to a consistent reference height (leave expansion gap if using shoe molding). Nail into studs and the bottom plate:
     • Use 18ga brads, 1 1/2"–2", angling slightly downward. Space nails roughly every 16–24" and at both ends.
   • At outside corners, glue the miter and add a pin near the tip on each side. For scarf joints, glue and nail through both layers into the stud.

7. Finish:

   • Set any proud nails with a nail set. Fill nail holes and joints with wood filler or spackle; sand flush.
   • Caulk the top edge to the wall and any tiny gaps at outside corners. Avoid caulking to hardwood floors—use shoe molding for a clean look and expansion.
   • Touch up primer if needed and apply final paint coat.

Tips for great results

• Acclimate wood trim in the room 24–48 hours to reduce movement.
• If the floor is noticeably out of level, scribe the bottom of the baseboard to the floor or use shoe molding to hide the gap.
• Label the back of boards during dry fits to keep track of orientation.
• For tight miters, add a tiny back-bevel (1–2°) so the visible edge closes optimally.

Common mistakes to avoid

• Prying without scoring the paint/caulk, which tears drywall paper.
• Nailing randomly. Missed studs lead to loose trim and future gaps—locate studs first.
• Using MDF in damp areas; it swells easily. Choose PVC or wood in bathrooms and laundry rooms.
• Over-caulking. Caulk small gaps only—thick beads shrink and look messy.
• Skipping glue on scarf and outside corner joints; glue reduces seasonal movement cracks.

When to call a pro

• Historic or elaborate profiles that need custom milling or perfect matches.
• Extensive water damage, mold, or subfloor issues discovered during removal.
• Lead-painted trim you don’t want to manage with lead-safe procedures.
• Curved walls, complex transitions, or integrated baseboard heating covers.

With a careful removal, accurate cuts, and tidy finishing, a replaced baseboard will blend right in and look like it’s always been there.