How to Install Baseboards and Get Tight Corners

Baseboards make a room look finished. The corners are where amateur jobs give themselves away.

Buy MDF baseboards for painted finishes (cheaper, straighter, takes paint beautifully) or pre-primed pine if you need to bend slightly along an uneven wall. Cut all your straight runs first, then handle corners last.

Inside corners cope, just like crown molding. Cut the second piece's profile to match the first piece's face — a coping saw and 5 minutes per corner. Coped joints absorb wall imperfections; mitered inside corners always gap.

Outside corners are mitered. Cut a test scrap first to confirm the actual corner angle (rarely exactly 45°). When you nail outside miters, glue both faces with a dab of wood glue and pin-nail through the joint to lock it together — no gap appears later as wood moves.

Nail with a 16-gauge finish nailer, two nails per stud, one near the top and one near the bottom of the baseboard. Fill nail holes with painter's putty, caulk the top edge to the wall, and touch up paint. The caulk-and-paint combo is what makes amateur trim look pro.