Set the beams
- Prepare the foundation: Before installing the beams, make sure the foundation is stable and level. Use concrete blocks, post anchors, or pier footings.
- Measure and cut the beams: Measure accurately and cut the beams to the right length. Use pressure-treated lumber for extra durability.
- Fasten with hardware and screws: Mount the beams to the foundation using strong connectors and stainless screws. Check that all beams are level and parallel.
Install the joists
- Decide the joist spacing: The spacing depends on the deck board dimensions. 60 cm (24 in) on center is standard for 28 mm (1 1/8 in) boards, while thinner boards, diagonal installation, and composite decking require 40 cm (16 in) — see what joist spacing should you use for a deck.
- Secure fastening: Use joist hangers or connectors and screws to fix each joist firmly to the beams. Check that joists are straight and not twisted.
- Extra support: For large decks or heavy loads, consider adding extra support joists or doubled members where needed.
Check the stability
- Level check: Use a spirit level to confirm the frame is flat and even across the whole deck.
- Test the strength: Walk the frame and verify that everything is solidly fastened and nothing gives.
- Adjust if needed: Make any corrections before the deck boards go down to avoid problems later.
Important tips for a lasting result
- Treated lumber: Use materials rated for moisture and ground contact.
- Moisture protection: Lay a membrane or joist tape on top of the joists to extend their life.
- Drainage: Ensure good drainage under the frame to avoid standing water and rot.
Use the deck calculator for accurate estimates
For simple, efficient planning, use the deck calculator on this page. It helps you estimate the decking and screws you need — typically 35–40 screws per m² (3–4 per sq ft) — so the surface materials match the frame you have built.
Build a deck that lasts for years — start planning today!