How to Make Baseboards for Stairs

Measure the distance you want from the outermost edge of the bullnose tip of one tread to the contoured area of your future baseboard. In many homes this distance is less than 2 inches. Mark the wall with this amount on two treads at least five treads apart.

Stretch a chalk line along the wall that crosses the two marks. Snap a chalk line on the wall. Examine the line and its relationship to the stairs carefully. It should be the exact same angle of the angle of the stairs. All of the bullnose treads should be the same distance from the line. The baseboard for this area will begin and end at a corner, against trim or where the baseboard becomes horizontal.

Create a paper template. Start at the top of the staircase. Tape thick paper to the wall where the angled staircase baseboard starts. Tape one long side of the paper to the chalk line. Cut the other side of the paper to follow the exact shape of the stair treads.

Use a ruler, pen, scissors and artist knife to cut out the shape of each tread so the paper hangs flat against the wall and tight to the staircase.

Tape a second piece of thick paper overlapping the first along the wall. Continue cutting out your tread pattern until the paper hangs flat and the paper is tight to the staircase. Tape the first and second pieces of paper together along the seam keeping both pieces flat and smooth. Add a third piece of paper and continue this pattern until you reach the point where the baseboard ends or goes horizontal.

Remove your template from the wall carefully. Turn it over on the floor and tape the back seams together to make the template stronger.

Place your baseboard material face side down on the floor. Position the template upside down on the baseboard with the straight edge along the contour edge. Tape the template to the baseboard and draw along the stair treads. Cut out your baseboard using a jigsaw. Slide the baseboard into place for a test fit.

Glue and finish nailing the baseboard in place using construction adhesive and a finish nail gun. Nail into studs as much as possible with one nail for every 8 to 10 inches of board.