Advice for preparing the ground

Ensuring water drainage:

On all non-draining ground, you must ensure a slope of at least 10 mm per linear metre, parallel with the joists’ length, for water to run off, while also making sure water does not collect at the lowest point of the decking.

Stabilising your ground:

You can lay your decking on even, sloping ground (flat concrete slab with no dips or bumps; re-profile if necessary), on piles or on
pedestals. For stabilised ground surfaces covered with geotextile, the joists should be laid on polymer pedestals. For ground that has simply been drained, concrete expansion spacers should be used to support the joists.”

Find out more; see Decking installation instructions, PU7