How to Make a Stair Cap

By Wade Shaddy

Stair caps fit over existing stair treads. They are installed to remodel or refinish stair steps. Stair caps save time and effort when stair treads have become weak, worn or unstable, because you don't need to tear out the old stair treads. Many stair caps are made by nailing bullnose molding to the leading edge, but that only results in more time and effort. It's best to start out with thick lumber and then route the bullnose directly to the face of the new stair cap.

List of Items Needed

  • Tape measure
  • 1 1/4 by 24 by 48 inch hardwood board
  • Pencil
  • Table saw or multisaw
  • Plunge router or handheld router
  • Oscillating tool with sanding accessories
  • Cordless drill or rotary tool with drilling accessories
  • Hammer
  • 2 1/2 inch finish nails
  1. Measure the width and length of the existing stair tread and write it down. Add 3/4 inch to the width measurement of the stair tread, or perpendicular to the grain of the tread.

  2. Cut the stair cap to the measurement using a table saw or multisaw. Set the fence at the lengthwise measurement to rip the length.

  3. Route a bullnose profile on the front edge of the stair cap, parallel to the grain pattern. Use a router with a bullnose bit to round the edge of the tread lengthwise.

  4. Sand the board with the oscillating power tool and sanding accessories. Sand parallel to the grain. Sand the edge thoroughly where you routed it to blend the router marks.

  5. Drill four small pilot holes for nails along both edges of the board, 1 inch from the edge with either the drill or the rotary tool with a drilling accessory.

  6. Slide the stair cap over the existing stair tread and nail it in place with a hammer and 2 1/2-inch finish nails.

Tips and Warnings

  • Finish stair caps before installation; use penetrating oil, paint or lacquer. If the stair cap fits too tight, trim off 1/16 inch at a time until it fits snug.
  • The measurements for the wood blank are an example. Purchase boards as close to the size of the treads as possible.
  • Always wear safety glasses when working with wood.

© Demand Media 2011