How to Replace Stairs With Slides

Pry off the stair treads and risers to reveal the stair stringers. Use a pry bar or crow bar to remove the boards and carefully remove any remaining nails with the claw end of a hammer. The stringers are basically the skeleton of a staircase to which the stair treads are attached; in most cases, there is a stringer on each side of the stairs and one in the middle.

Mark each point of the stringers with a framing square, turning each 90-degree angle into a 45-degree angle suitable to hold a slide. After marking the correct angle on the first stair, run a chalk line from top to bottom and snap the line to mark along all the stairs on the stringer at once.

Cut the stringers along your marks with a circular saw, or a reciprocal saw if access is difficult with the circular saw.

Lay 2-by-4-inch boards to span the width of the staircase. Nail or screw them in place into the stringers, using two screws per stringer step. Lay the boards on their wide sides and line them up directly on the 45-degree angle cuts.

Measure and cut plywood to fit the width of the staircase. Lay the plywood on top of the 2-by-4s and screw it in place, using at least three screws per 2-by-4 board. You now have the basic structure of the slide, although plywood creates too much friction to allow you to slide down.

Measure and cut coil stock aluminum to fit within the staircase. You may be able to purchase the metal cut to fit your project and, in some cases, may only need a single piece of metal.

Apply construction adhesive directly to the plywood, position the metal over the plywood and push from the center out to the edges to remove air pockets. Screw the metal into place on the outside edges of the slide using aluminum flat-head screws.

Seal the joints between two pieces of metal, if applicable, with a bead of construction adhesive to provide a smooth transition with minimal risk of injury from exposed sharp metal edges.

Nail quarter round molding into place along the sides of the new slide. The molding creates a smooth finish and also conceals the sharp outer edges of the thin metal. Install a thin, metal threshold to protect against the sharp edges at the top and bottom of the slide.