Modern Slat-Top Outdoor Bench

If staining or painting: do the long 2x4s now, flat, and let them dry — the slots in the finished bench admit no brush.

Choose the best-looking long 2x4 and leg pair and set them BEST FACE DOWN (the show face self-levels against the bench). Lay out one long slat with a leg at each end, position 1x4 spacers on top, and glue and fasten the spacers to both the slat and the legs.

Add the next 2x4 layer (long slat + two legs) onto the spacers — glue, fasten — then the next 1x4 spacer course, and repeat. Keep leg positions aligned layer to layer (a square held against the leg stack every course catches drift early) and stagger the screws so layers don't collide.

The source's step 4 is the honest instruction: continue until you run out of boards. Seven slat layers is the plan; the method doesn't care if you make it nine.

Flip the bench show-face up, let the glue cure fully (overnight — a lamination under seat loads earns its cure time), and sand: ease every slat's top edges and the leg corners, then touch up finish on cut ends and the top.

Set it against the long wall it was born for. The shadow lines do the rest.