How to Build Stairs with a Landing

Install and trim the decking before starting the installation of the stairs. Lay out and pour any footings needed for the landing platform and install the landing pad. Compute the rise and run of both sections of the stairs. Build the landing platform using the same techniques you would use for a deck (the platform is, in fact, a miniature deck). Install and plumb the posts, build the perimeter frame, hang joists in joint hangers, and attach the decking-with the same orientation and pattern as the deck, if possible.

Make stringers for the lower stairs using your earlier computations for the rise and run. Attach 2x4 cleats to the backside of the rim joist that faces the concrete pad. These cleats will support the crossbrace to which you will attach the stringers. The length of these cleats should equal the combined height of the rim joist, the unit rise, plus ½ inch (so the crossbrace will extend beneath the stringer). Fasten the crossbrace (2x pressure-treated lumber) to the cleats with deck screws, cut the nailer to length and width from 2x pressure-treated lumber. Install a crossbrace on the upper rim joist for the upper-stair run also.

Attach the center stringers with slopeable joist hangers. Level the tops of the stringers. Connect each outer stringer to the crossbrace with an angle bracket, making sure the tread lines are level with each other and the center stringers. Mark the location of the bottom end of each stringer on the concrete pad, making sure the spacing between stringers is consistent throughout.

Fasten an angle bracket to the pad with self-tapping masonry screws in pre-drilled holes. Anchor the stringers to the brackets with the nails recommended by the manufacturer. Cut treads from the same material as the decking and fasten them to the stair angles with short lag screws (or the fasteners recommended by the manufacturer). Cut stringers for the upper-stair run and mark their locations on both sides of the landing. Snap a chalk line across the landing at the marks.

Cut a toe kick (a pressure-treated 2x4) so it will fit between the stringers and attach it to the landing with its front edge on the chalk line. Cut a notch in the bottom end of the center stringer to accommodate the toe-kick. Attach each outer stringer to the upper deck with angle brackets. Install the center stringer in a slopeable joist hanger.

Drive two deck screws through each outer stringer into the toe-kick. Toenail the center stringer to the toe-kick with deck screws. Attach stair angles to the stringers as you did for the lower-stair run. Drive fasteners through the cleats and into the undersides of the treads.