Step 1 Cut timber to suit dimensions of mattress, ensuring long sides of frame have additional 400-600mm of length – this will help support frame in ground. Remove any stray nails.
Step 2 On ground or flat surface, butt join posts around mattress to form frame. Predrill corners, then line up posts and drive in screws to secure.
Step 3 For a decorative touch, cut 1 timber post slightly longer than short side. Position on top of frame, predrill and drive in screws to secure.
Step 4 In desired location, dig 400-600mm-deep holes for legs of frame. With help, position frame in holes, backfill and compact. Check it is plumb and adjust if necessary.