What you’re building
Three slats glued edge to edge make a top 10½ inches wide and 1½ inches thick. Two more pairs glued the same way become slab legs, 7 inches wide and 9 inches tall. A single stretcher on edge ties the legs together under the top and stops the stool racking side to side. Every joint is glue plus screws, and every screw goes in from a face you can reach.
The stool ends up 10½ inches tall, which is one comfortable step for an adult and a good height for a kid at the sink. It’s a step stool, not a ladder: one foot on it, not two feet on the edge.
Pick the board
Sight down the length of the 2x4 at the store and reject anything with a visible twist. A gentle bow along the length is fine, since nothing here is longer than 16 inches. Avoid boards with a knot larger than a quarter in the middle 4 feet; that’s where the top slats come from. If the board feels heavy and cold, it’s wet. It’ll still work, but let it sit inside for a few days before you glue anything, or the top will shrink and open a gap.
Cut
Cut in the order on the diagram, starting with the three top slats from the cleaner end. Cut the four leg boards next, then the stretcher. Mark each piece with its letter as it comes off the saw. Check the four leg boards against each other; if one is a hair long, trim it now. Legs that don’t match are the only way this stool ends up wobbly.
Glue up the top and legs
Lay the three top slats side by side, best faces down, and roll them so the growth rings alternate up, down, up. That keeps the top flat as it dries. Spread glue on the mating edges, push them together, and clamp across the width. Wipe the squeeze-out with a damp rag. Do the same with each pair of leg boards. Let everything sit for at least an hour before you take the clamps off, and overnight if you can.
Once dry, sand the glue lines flush with 80 grit and then go over everything with 150. Round the corners of the top slightly with the sandpaper; sharp 2x4 corners splinter.
Assemble the legs and stretcher
Stand the two leg panels on their ends 9½ inches apart, with the stretcher on edge between them. The stretcher’s top edge should be flush with the top of the legs. Run glue on both ends of the stretcher, clamp it between the legs, and check that the assembly is square. Drill two countersunk pilot holes through each leg panel into the stretcher, centered on the stretcher’s thickness, and drive the 2½-inch screws.
Attach the top
Set the top upside down. Measure in 1¾ inches from each end and each side and mark where the leg panels sit; the overhang is the same all the way round. Glue the top of each leg, set the leg assembly in place, and clamp or hold it while you flip the whole thing right side up. Drill countersunk pilot holes through the top into each leg board, two per board, and drive the 3-inch screws. Pilot holes matter here: you’re screwing into end grain near the end of a 2x4, and it will split without them.
Finish
Ease all the edges with sandpaper. For the shop, leave it bare. For the kitchen, two coats of a wipe-on polyurethane or a hardwax oil is enough, and it’ll pick up a nice color as it ages. Add self-adhesive rubber feet if it’s going on a hard floor.
If something goes wrong
- Rocks on the floor. One leg is long. Set the stool on a flat surface, find the high corner, and sand the bottom of that leg until it sits flat.
- Gap in the top glue line. The slats weren’t clamped tight or the board was wet. Fill it with glue and sanding dust, or accept it; it’s structural either way.
- Screw split the leg. Back it out, put a little glue in the split, clamp it, and drive the screw again through a larger pilot hole.