Heavy-Duty Adirondack Chair with Footstool

The stringers come off the miter saw with a sharp top corner where the 35° and 20° cuts meet. Mark the cut-off with a speed square and take it off with the jigsaw, on both stringers.

Do them together and compare — the two stringers set the seat plane, and they need to match each other more than they need to match the drawing.

Join the front apron (the 22-1/2" 2x4) to the two front legs, two 2-1/2" screws per joint. Keep the apron square to the legs — this U-shape is the reference everything else gets fitted against.

Stand the assembly upright on a genuinely flat surface. Attach each stringer to the front apron with a SINGLE screw, then check that the chair sits flat and doesn't rock.

One screw is the point: it's a pivot. You can rotate a stringer a degree or two to kill a rock now. After the second screw goes in, you can't.

Attach the back legs and the 2x2 arm supports, still checking after each piece that the chair sits flat. Once nothing rocks, go back and finish screwing the stringers to all four legs until the frame is rigid.

Starting at the front edge, screw the seat slats to the stringers with 2" screws and glue, leaving a 1/2" gap between slats. The gaps drain rain; a solid seat on an outdoor chair is a puddle with armrests.

Screw the back support 2x4 across the back legs with the 2-1/2" screws at the height shown in the diagrams. This bar and the base support are what the whole back panel hangs on — check it's level across the chair, not just attached.

Lay the five back slats on the base support with roughly 1/2" gaps, screw them to the base, then tie the tops together with the 1x4 top support and the 1-1/4" screws — the short screws matter here, anything longer comes through the face.

For the arch, trace a large round object — a trash can lid is traditional and works — across the slat tops, and cut the curve with the jigsaw. Cut with the panel assembled so the arc flows across all five boards.

Stand the finished back panel inside the chair frame and lock it down: 2-1/2" screws through the base, 2" screws into the back support. Sit in it before the next step — the back takes your full weight at a lever angle, so if anything flexes, add screws now.

Screw and glue the arm rests to the arm supports and the tops of the front legs. Round the front corners and soften every arris with the sander — arms are the part of an Adirondack people actually touch for hours.

The footstool is its own small cut list: two stringers at 23-1/2" with parallel 30° ends, two legs at 13-3/4" with one 30° end, six top boards at 22-1/2".

Cut the stringer angles on the miter saw first, then mark the corner cut-offs with a square and finish with the jigsaw — same technique as the chair stringers.

Screw and glue the six top boards across the stringers with 2" screws, keeping the gaps consistent with the chair seat so the pair reads as a set.

Screw the legs to the insides of the stringers with the 2-1/2" screws. Set the stool against the chair and check the deck angle meets your legs comfortably.

Sand everything, then either leave the wood to weather or put an exterior finish on — and if you used glue at every joint like you should have, this pair will outlast the deck it sits on.