How to Build Steps Out of 3/4-Inch Plywood Panels
- 1). Cut a rectangle from 3/4-inch plywood as wide as the number of steps you want multiplied by 10 inches and as long as the number of steps you want multiplied by 8 inches, plus 8 inches, using a table saw.
- 2). Measure from one corner along the edge you multiplied by eight using a tape measure and mark the plywood with a pencil. Use a carpenter's square and mark a perpendicular line in from the edge by 10 inches. Flip over the square and mark a line perpendicular to the 10-inch line 8 inches up into the middle of the plywood.
- 3). Flip the square again and draw a second 10-inch line. Flip and draw an 8-inch line, continue until you reach the opposite edge of the plywood, having drawn the riser and tread supports for your sides, or stringers.
- 4). Cut along the "zigzag" line you created with the carpenter's square using a circular saw to separate the two stringer pieces.
- 1). Sand the edges of the tread and riser supports until they are smooth with a random orbital sander and 100-grit sandpaper.
- 2). Cut enough 10-inch wide strips of 3/4 inch thick plywood for each tread on the table saw. Make enough for two extras for the rear of the stairs. Cut the stairs to length at 32 inches and the rear cleats at 30 1/2 inches, using the miter saw.
- 3). Use a drill and 1/8-inch wood bit but to bore two pilot holes at the end of each tread and riser, 3/8 inches in from the end, evenly spaced. Bore four pilot holes along one long edge of each tread and riser 3/8 inch from the edge.
- 1). Apply glue to the front of the bottom riser edge on both side pieces and stand one of the sides upright. Position the riser on edge, perpendicular to the side piece with one end overlapping the stair side by 3/4 inch. Drive one 1 5/8-inch screw through each pilot hole in the riser into the face of the riser support on the stair side using a cordless drill.
- 2). Align the remaining side piece to the opposite end of the riser and install two screws. Add the remaining risers in the same way, applying glue to the face of the riser support and driving the screws through the riser into the side piece.
- 3). Apply glue to the ends of the two back support cleats. Fit one into the back with its face flush with the back edge of the side pieces and its top edge even with the top of the side pieces. Drive two screws through the side piece into each end of the support. Install the remaining support at the bottom in the same way.
- 4). Apply glue to the top of the riser edges and the tread supports. Fit a tread onto each riser. Drive a screw down through each hole into the risers and side pieces. Turn over the stair and drive screws through the holes in the bottom edges of the risers into the back edge of each tread.