Step-by-Step

1. Plan the size. Common heights are one or two boards (e.g. 150 mm or 300 mm). Mark out the footprint with string and pegs.
2. Prepare the ground. Remove turf, level the area, and lay a compacted layer of gravel if drainage is poor. Add a weed-control membrane if desired.
3. Cut your boards. Mitre corners (optional) or use square butt joints. Pre-drill to reduce splitting.
4. Fit corner posts. Cut short internal posts (e.g. 450–600 mm long). Stand them just inside each corner, tops flush with the finished bed height.
5. Assemble the first course. Fix the long sides to corner posts, check square, then fix the short sides. Use 2–3 screws per joint.
6. Add mid-span posts. For longer sides, add internal posts ~1.2–1.5 m apart for stiffness. Fix boards to these posts as you go.
7. Build additional courses. Stagger board joints where possible. Treat all cut ends with end-grain preservative before fixing.
8. Line & fill. Line the inside (optional) to reduce soil contact and extend life. Fill with soil/compost mix and water in.
9. Finish. Top off with a neat edge, cap, or chamfer if desired.

Quick Estimator (Boards, Posts, Screws, Membrane & Soil)

This gives an indicative shopping list. Adjust to your preferred board/post sizes.

Notes: For components in direct ground contact (posts/boards), consider UC4 treatment. Line the interior to reduce soil contact and extend life. Treat cut ends with end-grain preservative. Figures are indicative and may need adjusting on site.

Disclaimer: Guidance only — may not reflect the latest standards or your site conditions. Check with a competent installer and local requirements where applicable.