Enter deck length and width, board width and joist spacing — we work out boards, joists and screws with a safe wastage allowance.
Assumes 5 mm gap between boards and 2 screws per board/joist crossing. Add framing timber separately.
For 145 mm boards with a 5 mm gap ≈ 6.7 lin.m per m². A 4 × 3 m deck (12 m²) needs ~80 lin.m — buy 10 % extra for end cuts.
400 mm centres for softwood and standard composite; 300 mm centres for hardwood or if boards run diagonally. Wider than 450 mm and boards flex underfoot.
Yes — 5–6 mm for kiln-dried softwood and composite, 3 mm for hardwood. The gap lets water drain and boards move seasonally without cupping.
Leave at least 150 mm of airflow beneath and a fall of 1:80 away from the house. Boards laid flush to the ground rot within two winters.
Estimates only. Check the paint tin / adhesive bag for the exact coverage of your product.