2x4 Firepit Bench

On a flat surface, screw each pair of legs to an armrest from the top, two screws per joint. The legs' parallel 10° ends give the assembly its lean — the armrest stays level while the legs rake back.

Measure and mark the support placements per the diagram, then attach the arm support and seat support with two screws per joint. Build the second leg set IDENTICAL to the first — check them against each other before the next step, because a mismatch here is a wobble forever.

Attach a back support to each leg set, screwed to JUST the top seat support for now — full attachment comes later, and you want adjustment room.

The two leg sets get this in MIRROR — one left, one right. This is the classic mistake in this build; dry-place both before driving screws.

If you're taking the strength upgrade, these are the boards you cut at ~32" so they reach the lower arm rail.

Screw the 45" bottom stretcher between the two leg sets. Wrestling two leaning assemblies and a stretcher alone is the hardest 90 seconds of the build — get a second pair of hands, or tack one seat slat across the top first to hold spacing while you fasten.

Lay the bench on its back and attach the back slats, starting at the top and working down.

Then the step the plan bolds for a reason: drive screws through the back legs into the back slats as well. The back-rest takes lean-back loads at a lever angle, and those extra screws are what carry it.

Stand the bench up, lay out the seat slats with even gaps, and screw them to the seat supports.

Sand everything — especially the front seat edge, the back of bare knees finds it every time — and put a real exterior finish on. A firepit bench lives its whole life uncovered in the weather.