Check the base and available height
- 1Boards
- 2Joists
- 3Pedestals
- 4Compacted aggregate
- 5Geotextile
- 6Ground
Over soil, build a stable, free-draining base. Over concrete, check the slab condition, fall and clearance below the threshold. Never leave joists standing directly in water.
Calculate aggregate for the baseTesCalculs→Read the installation instructions for the range
Record the maximum joist centres, allowable spans, side and end gaps, permitted overhangs, ventilation requirements and clip type. Keep each value separate.
These are product-specific manufacturer specifications, not universal construction rules.
Set out the supporting structure
- 1Joists
- 2Pedestals
- 3Centre-to-centre grid
Joists normally run perpendicular to the boards. Provide double joists at board-end joints where the instructions require them, and support every board end.
Calculate the number of decking pedestalsTesCalculs→Calculate quantities and place the order
- 1Boards
- 2Gap between boards
- 3Length to cover
Enter the usable board width, stock length, gap, joist centres and price for your chosen product. The calculator rounds up to whole boards and separates theoretical requirement from the quantity to buy. Composite clips must still be taken from the product instructions and pack size.
Calculate boards and joists — verify clipsTesCalculs→Lay the boards and complete the edges
Start from a perfectly straight reference line. Follow any specified board direction, the manufacturer’s movement gaps and the clip tightening instructions. Keep drainage routes and ventilation openings clear.