Installing Floor Trim Inside Corner

Cut the trim square if it butts into.

Installing floor trim inside corner.

When it comes time to install trim around the corners of your room or walls longer than the typical run of trim use these three joints. That s generally because corner tape joints don t always get filled or sanded all the way to the floor. Trim at inside corners often won t meet evenly despite a perfectly cut cope. Continue to cut and install trim until reaching the end of the wall.

Cut the inside corner of the last piece at a 45 degree angle and continue around the room. Use a coping saw to trim out excess material behind the cut so the pieces fit snugly. The technique described here modified for diyers will also work for other trim moldings such as door and window case moldings or chair rail moldings. I know a few drywall finishers who don t like to bend over.

But room corners sometimes vary slightly from perfect 90 degree angles and professional trim carpenters have a number of tricks they use to ensure that baseboard moldings fit perfectly. For inside corners cut the piece to length at a 45 degree angle with a miter saw. The angled cuts the slope of the floor and the irregularity of the walls all work against you as you try to get those tight even corner joints.