How to Install Baseboards in Any Room

Installing baseboards involves measuring and cutting trim pieces to fit along the bottom of walls, then securing them with finishing nails and filling gaps with caulk for a clean, finished look.

1. Clear the Stage First. Carefully pry off old baseboards using a pry bar and putty knife. Remove any remaining nails from the wall and sand down rough spots. Vacuum the area thoroughly to remove dust and debris. Check that walls are plumb and mark any areas that may need shimming.
2. Map Before You Cut. Measure each wall section where baseboards will be installed. Start with the longest, most visible wall first. Plan your joints so that the most noticeable seams fall in less prominent areas. Mark stud locations on the wall using a stud finder, as you'll want to nail into studs for the strongest hold.
3. Start Big and Bold. Measure the longest wall and cut your first baseboard piece to length using a miter saw. Make this cut square on both ends since it will butt against other pieces. Test fit the piece to ensure it sits flush against both the wall and floor. If there are gaps due to uneven walls, mark areas that need adjustment.
4. Master the Angles. For inside corners, cut both meeting pieces at 45-degree angles. For outside corners, also cut 45-degree angles but in the opposite direction. Test fit all corner joints before nailing. If corners aren't perfectly square, adjust your angles slightly until pieces fit together tightly. Use a coping saw to fine-tune inside corner joints if needed.
5. Fasten for the Long Haul. Apply a thin bead of construction adhesive to the back of each piece before installation. Position the baseboard against the wall and nail it in place using 2-inch finishing nails driven into wall studs. Place nails every 16 inches along the length and at each end. Drive nails slightly below the surface using a nail set.
6. Hide Every Imperfection. Fill all nail holes with wood filler using a putty knife. Let dry completely according to manufacturer's instructions. Sand filled holes smooth with fine-grit sandpaper. Apply painter's caulk along the top edge where baseboard meets the wall and along the bottom where it meets the floor. Smooth caulk lines with your finger for a professional finish.
7. Seal and Beautify. Apply primer to all new baseboards, paying special attention to filled nail holes and caulked areas. Once primer is dry, apply two thin coats of your chosen paint, allowing proper drying time between coats. Use a high-quality angled brush for smooth coverage and clean lines.