How to Install Base Molding on Stairs

When the base molding in your home begins to look old and cracked, you will want to replace it. Installing base molding is a straightforward task. However, it gets a little more complicated when there are stairs involved. Installing base molding along stairs requires some knowledge of angles and woodworking. If you are new to woodworking, practice making cuts on scrap pieces of molding before cutting the pieces you wish to install.

Install Base Molding on Stairs
  1. Measure 12 inches from one end of a piece of molding. Cut the molding straight down at this mark so that you have a 12-inch piece of molding with two straight edges.
  2. Stand the short piece straight up on the second stair from the top. Push the long edge of the piece against the front portion of the stair landing. Use a level to make sure the piece is standing straight up and down. Make a mark on the template where the stair landing hits it. If your stair has an overhanging lip, mark where the underside of this lip hits as well.
  3. Use a speed square to draw lines across the piece from the two marks. Hold the piece flat, with the outer side facing up. Place the bottom edge of the piece against the back of the first stair with the outer side touching the underside of the lip. Draw a line across the piece where the lip hits.
  4. Cut out the notch marking you just made, on the bottom edge of the piece, with a miter saw. Lay the piece on the miter saw table so that the notch is on your right-hand side and the bottom of the piece is against the saw blade. Cut the end of the piece off at a 45-degree angle. Slide the piece down and make the same cut on the other end. Make sure each cut meets exactly with the corner of the piece so that the piece is still 12 inches long.
  5. Place the piece of molding against the wall. Make sure the notch you cut out is over the lip of the stair. Use a stud finder to locate the studs in the wall. Secure the piece to the wall studs with finishing nails.
  6. Cut a 45-degree angle off a new piece of molding. Place the cut edge against the edge of the installed piece of molding so that they butt up and make a 90-degree angle. Mark on the new piece where the edge of the stair hits it.
  7. Place the new piece back on the miter saw and cut off the end of the molding, where the edge of the stair hit, at a 45-degree angle. Take the piece back to the stairs and put it in place. Locate the studs behind the wall and secure the piece to the studs with finishing nails.
  8. Cut another piece of molding to 12 inches and begin the process all over again. Continue in this way until the entire stairway has molding installed.

Things You Will Need

  • Tape measure
  • Pencil
  • Level
  • Speed square
  • Miter saw
  • Stud finder
  • Finishing nails
  • Hammer


  • For stairs where no studs are available, spread a thin layer of construction adhesive on the back of the molding and hold the molding against the wall to allow the glue to set.

Photo Credits

  • Comstock/Comstock/Getty Images