What footings does a deck need?

Most decks in Australia sit on concrete footings, with a galvanised steel stirrup in each one that holds the timber post at least 75 mm above the concrete, according to Timber Queensland and WoodSolutions. How deep and wide each footing goes depends on your soil and the weight of the deck, so it is worked out for your site, not taken from a standard size.

Below are the types of footing used in Australia, what decides their size, the termite rules in Queensland, and what each type costs. These are market prices from cost guides, checked on 5 October 2026. They are not a quote from us.

What types of deck footings are there?

There are seven main types. The first two hold up most timber decks.

ATFA is the Australasian Timber Flooring Association. All sources checked 5 October 2026.

What footings do most decks use?

A concrete footing with a galvanised steel stirrup. The WoodSolutions deck design guide calls this the most common method, and the ATFA says these footings are "preferred". The post is fixed into the stirrup, so the timber never sits on the concrete.

Timber Queensland says there must be at least 75 mm between the top of the concrete and the bottom of the post. That gap does two jobs. Air gets under the post so it dries out after rain, and the gap works as a termite inspection zone.

The other common choice is to set the post straight into the concrete. WoodSolutions says to use no-fines concrete and slope the top away from the post so water runs off. The post has to be H5 treated pine or in-ground Durability Class 1 hardwood. The ATFA points out the catch: if that post rots years later, it is harder to replace.

How deep and wide should deck footings be?

There is no single size. WoodSolutions says footings are designed to AS 2870 (Residential slabs and footings) or AS 1684 (Residential timber-framed construction), and that the soil type and expected loads usually need to be known first. The ATFA says the same, and adds that a structural engineer may be needed.

So the first step is a site classification, which works out what kind of soil you have. In Queensland, site classification is a job that needs a QBCC licence at any value. A tiled deck, or one carrying a spa, is outside the normal tables, and WoodSolutions says an engineer should design it.

To give you a feel for the sizes, one cost guide (The Quote Yard, Adelaide, May 2026) describes:

• pad footings of about 400 x 400 x 200 mm reinforced concrete, for ground-level decks on stable soil
• bored piers 300 to 450 mm across and 1.0 to 3.0 metres deep, for raised decks and reactive clay

Those are South Australian examples, not a Gold Coast rule. How many footings you need depends on how far the bearers span between posts, which our guide to deck joist spacing explains. Your certifier or engineer has the final word for your block.

What clearances and rules apply to deck footings?

A few numbers are set, whatever the soil.

A deck attached to the house is different. Both Timber Queensland and the ATFA say it needs diagonal bracing, whatever its footings.

Can you build deck footings without digging?

For some decks, yes. There are three no-dig options:

• Screw-in footings. A steel pile is screwed into the ground. GroundPlug sells deck footings in 600, 750 and 1,000 mm lengths that go in with a battery impact wrench.
• Deck blocks. A block sits on top of the ground. BuildTuff sells its TuffBlock for floating decks, sheds and walkways.
• Pedestals. These sit on an existing slab, so the slab does the job of the footings.

For very low decks, Timber Queensland adds two more: joists on low concrete beam walls, or bearers laid on a well-drained gravel, sand or concrete base. Bearers on the ground must be in-ground Durability Class 1 hardwood or H5 treated pine.

Any footing still has to suit the deck's design and your soil, so if your deck needs building approval, ask the certifier before you buy a no-dig system. On the Gold Coast, a deck needs approval unless it is under 10 m2, under 1 metre high and meets all building requirements. Our guide to council approval on the Gold Coast has the detail.

What are adjustable deck footings?

Usually, adjustable pedestals. These are stands that wind up or down, so the deck sits level. They go on a hard surface such as a slab, balcony or roof terrace.

Adheseal, a Queensland supplier, lists Buzon pedestals for decks and pavers, starting at 18 mm high. Some models have a built-in slope corrector for falls of 0% to 5%. That means the deck can sit level on a slab that slopes for drainage.

Some steel footing systems adjust too. All Footings, a Victorian maker, sells concrete-free steel footings that it calls "fully adjustable to suit specific needs".

What are the termite rules for deck footings in Queensland?

The deck and the house it touches both need protecting. Queensland still uses the National Construction Code 2022 (NCC 2025 starts here on 1 May 2027). Its Part 3.4 on termite risk management applies where subterranean termites "are known to present a potential risk of attack". The NCC rules out Tasmania only, and the City of Gold Coast lists "termite protection to adjacent buildings" as something every deck must consider.

Under the NCC:

• steel, concrete, masonry, and timber that is naturally termite resistant or treated to AS 3660.1 count as not subject to termite attack
• decks are "attachments", which need either their own termite management system or an inspection zone between the deck and the house
• in Queensland, a termite management system must last at least 50 years on a house, unless it is easy to top up or replace

The 75 mm gap at each stirrup is an inspection zone. For posts set in the ground, Timber Queensland says protection comes from stainless steel mesh socks or caps, or chemical treatment of the soil around them. Chemical termite work needs a QBCC licence at any value.

The gap to the house matters too. WoodSolutions says that where a termite barrier protects the house, AS 3660.1 needs the deck at least 25 mm from the building, or the barrier must be extended to cover the deck. Our decking timber guide shows which timbers are termite resistant.

What is different about deck footings on the Gold Coast?

Salt air and pools. Timber Queensland says stirrups must be hot-dip galvanised, and that spots "close to the coast, swimming pools" need higher protection on steel connectors. The ATFA says makers of steel posts may warn against using them within 300 metres of the sea or near salt pools. It recommends stainless steel or silicon bronze fixings within 1 metre of a pool.

One more Queensland rule: building work over $3,300, counting labour and materials, needs a QBCC licensed contractor.

How much do deck footings cost?

About $150 to $400 each for a concrete footing or screw pile in Brisbane, according to Sparky's September 2026 guide, fully installed. We could not find footing prices for the Gold Coast.

Parts alone cost less. On 5 October 2026, GroundPlug listed its screw-in deck footings at $53 to $73 each, and Adheseal listed Buzon pedestals at $3.66 to $15.46 each. Those prices do not include fitting them.

On reactive clay, The Quote Yard says deeper bored piers usually do better than shallow pads, and they cost more. For the full price of a deck with footings, see our deck cost guide for the Gold Coast.

We build timber and composite decks across the Gold Coast, from pool decks to deck stairs and landings. Brett checks what your deck needs, handles the approval, and gives you a timeline with the proposal. More on what we build is on our deck building page.

Where do these figures come from?

Checked on 5 October 2026: WoodSolutions Technical Design Guide 21, Domestic Timber Deck Design (revised October 2020); Timber Queensland Technical Data Sheet 4, Residential Timber Decks (revised March 2014) and Data Sheet 13, Decks Close to or on the Ground (revised February 2014); the ATFA's Residential Timber Decks industry recommendations (version 2, April 2020); Sparky (Brisbane decking costs, September 2026); The Quote Yard (South Australian deck building costs, May 2026); and product pages from GroundPlug, BuildTuff, All Footings and Adheseal. Rules from the NCC 2022 Housing Provisions Part 3.4, the Australian Building Codes Board's NCC 2025 adoption table, the City of Gold Coast and the QBCC. We will check the prices again every three months.

See our decks and patios work, or check what your job will cost.