Decking foundations

Decking
ground screws.

Ground screws for timber, composite and raised decking, with the screw positions planned around the actual deck beams and joists.

Timber deck-style subframe supported above the ground
Why use them?

A practical foundation for decks.

Uneven sites

Individual ground screws can help deal with slopes and changes in level without building a full concrete base.

Match the deck frame

The screw positions should follow the actual beams and joists so the deck is supported where it needs it.

Accurate set-out

Ground screws can be positioned to match the dimensions and shape of the finished deck.

Supply or install

Experienced installers can buy supply only, or Forti Nova can quote supply and installation.

Design first

How many ground screws does a deck need?

There is no reliable spacing rule for every deck. The number of ground screws depends on the deck size, beam spans, joist layout, expected loads, fixings and ground conditions.

Start with the deck frame and put support where the beams need it. This is especially important for raised decks, hot-tub areas, commercial terraces or decks carrying unusually heavy loads.

Understand load calculations
01

Deck dimensions

02

Subframe / beam layout

03

Site access & ground

Decking questions

Ground screw decking questions, answered.

Straight answers on screw quantity, installation, size, sloping sites and how ground screws compare with concrete.

01

Can ground screws be used for decking?

Yes. Ground screws can support timber, composite and raised decking. The screw positions should follow the deck beams and joists, and the screw size needs to suit the load and ground conditions.

02

How many ground screws do I need for decking?

The number depends on the deck size, beam spans, joist layout, expected loads, screw size and ground conditions. The screws should be positioned around the actual deck frame rather than using a fixed screws-per-square-metre rule.

Understand load and spacing
03

How do you install ground screws for decking?

The screw positions are marked out to match the deck frame, then the ground screws are installed and levelled before the beams are fixed above. The spacing should follow the actual deck design rather than a generic chart.

See the installation process
04

What size ground screws do I need for decking?

Ground screw size depends on the deck loads, ground conditions, fixings and how deep the screw needs to go. A longer screw is not automatically better, and deck area alone is not enough to choose the size.

See the size guide
05

Are ground screws suitable for sloping decking?

Yes. Ground screws can work well on sloping or uneven sites because each support point can be installed to the level needed for the deck frame.

06

Are ground screws cheaper than concrete for decking?

They can be. Compare the full cost of digging, spoil removal, concrete, labour and access against the ground screws, installation and any support beams or brackets. Do not compare only the price of one screw with a bag of concrete.

Compare with concrete
Decking project

Need a ground screw layout and price?

Request pricing