How Much Does Decking Cost Per Square Metre?

Decking Cost per m2: Price according to the Building Material

You want a beautiful deck, but you also have a budget. That means balancing several factors, including how large to build the deck, what features to include, and how much to spend on decking materials. Use this cost guide to learn how much you’ll pay per square metre for decking materials in Australia.

How Much Does Decking Cost per m2?

The typical cost to build a timber deck in Australia is $170 to $210 per square metre, depending on your decking project’s design, materials, labour costs, and site conditions. If you are building a deck with hardwoods or composite, homeowners could spend $320 or more per square metre. Custom balustrades, pergolas, lighting, and other amenities are additional costs.

Building a deck includes the cost of materials and decking installation, but because decks differ in size, complexity, etc., a survey of retail decking prices for uninstalled boards is a better approach. It gives you a true apples-to-apples comparison.

Decking Cost by Construction Material

The pricing provided below focuses on decking materials commonly available in Australia. Check with local retailers to see whether they stock the type of timber or composite deck boards you want. If not, factor in the fees required to ship them to your location. Keep in mind that the decking installation cost can equal or exceed the cost of the decking materials. If you’re a DIYer, get building permits and local council approval of your plans.

Timber Decking Cost per m2

Pressure-Treated Pine

This decking is popular worldwide because pine timber is readily available and renewable, resists rot and insects, and can be stained or painted in almost any colour you like. It’s also less expensive than most other decking options. The main drawback to pressure-treated pine decking is that it tends to shrink, split, and warp more than other timber decking. It also includes anti-rot chemicals and biocides (CCA, ACQ, LOSP, or Tan-E) that some people prefer to avoid. Expect to pay $43 to $48 per square metre for pressure-treated pine decking.

Hardwood Timber

There are many types of hardwood timber decking, including merbau, jarrah spotted gum, karri, blackbutt, and ironbark (grey and red). Narrow deck boards (90mm) are slightly less expensive on a square-metre basis than wider ones (135 to 140mm), and most hardwood decking comes in random lengths. If you plan to build your new deck using only long deck boards—5.4m to 6.1m—, expect to pay double the listed amounts. Likewise, thick decking materials—up to 40mm—can add as much as $200 per square metre to the prices listed below.

Merbau. This dense wood is very durable. It costs $73 to $80 per square metre. Pre-oiled decking and grooved deck boards are slightly more expensive.

Jarrah. This is a traditional timber for use in exterior applications because it is naturally resistant to the elements, termites, and other insects. It is also strong and has an eye-catching look. It costs $100 to $115 per square metre.

Spotted gum. This timber decking has a wide price range of $67 to $160 per square metre. The cost will vary depending on the grade of timber, its configuration, and the treatments applied to it.

Karri. This eucalyptus species is native to Australia and has a light pink to reddish brown hue. Pre-oiled karri costs $50 to $75 per square metre.

Blackbutt. Another native tree, this fire-resistant timber, has a golden yellow to pale brown colour. It costs $88 to $180 per square metre.

Ironbark. Sometimes called mugga, the heartwood of this timber is a dark red or brown and has a fine, interlocked grain. It is very durable but can be difficult to work because it is very hard. This decking costs $100 to $140 per square metre.

Softwood Timber

Softwood decking typically refers to cedar and redwood, which are naturally resistant to moisture damage and insects. While pine is also a softwood, it lacks the natural durability of cedar and redwood. That’s why pine must be infused with biocides and preservatives before it can be used as decking.

Cedar. Most cedar deck boards are Western red cedar, a tree species native to the USA, where it sells for about $85 per square metre. It is seldom used for decking in Australia, however. Native red cedar (Toona ciliate) is typically used as a veneer, not decking.

Redwood. Like Western red cedar, redwood is an aromatic timber native to the Western USA and contains natural substances that help it repel insects and resist water damage. It is difficult to find in Australia, but redwood decking sells for about $120 per square metre in the USA.

More information about Australian and other wood species is available at Wood Solutions, a website run by Forest & Wood Products Australia Ltd (FWPA), a not-for-profit company that provides research and development in support of the Australian forest and wood products industry.

Composite Decking Cost per m2

High-quality composite decking has a longer lifespan than most timber decks and comes with fewer maintenance costs than any other decking material. In fact, the quality of composite decking has never been better, and major manufacturers have a good, better, best pricing structure. They also offer accessories that integrate with the decking, including balustrades and lighting. The cost of the decking varies by manufacturer. It’s possible to spend as little as $120 per square metre, but the best composite decking, such as Trex decking, costs $215 to $265 per square metre.

Factors that Affect Decking Costs

The grade (quality) of timber or composite decking, its availability, and the distance it must be shipped are the major factors that affect the cost of decking materials. To keep costs down, look for timber species and composite decking that are in stock locally. Not only will these products cost less, but deck builders will be more familiar with using them, producing a better result.

How Much Does It Cost to Protect your Deck per m2?

Wood decks need more protection than composite decks, which typically only need to be cleaned with a mild detergent twice yearly. In addition, pressure-treated pine decks are typically coated with a water-based stain, while hardwood decks take oil-based coatings, sometimes referred to as waxes or varnishes.

Stains

Decking stains usually contain more pigment than decking oils and can change the deck’s colour to almost any shade. If you prefer the natural look of your timber deck, semi-transparent stains are available. Transparent stains also allow the timber to turn a natural grey. Expect to pay $115 to $125 for four litres of stain. Assuming coverage of 10 to 12 square metres per litre, stain adds $2.40 to $3.15 per square metre to the cost of decking.

Oil Coatings

Most decking oils protect timber decks without drastically changing the look of the timber. Expect to pay $95 to $120 for four litres of an oil-based finish. Assuming coverage of 8 to 10 square metres per litre, an oil coating adds $2.40 to $3.70 per square metre to the decking cost.

Professionally Applied Coatings

If you hire a professional to coat your newly installed timber deck boards, expect to pay $55 to $85 per square metre. It will cost you more if the deck was coated previously because the old coating must be removed completely before a fresh coat can be applied. Plan to reapply deck stains every three to five years and oil coatings more frequently.

Structural Protection

Before installing your deck boards over the timber joists, consider applying joist protector waterproofing tape to stop timber rot. The tapes come in several formulations and formats, so research the cost-performance ratio of the each before you buy. For instance, there are major differences between butyl tape vs putty tape.

Conclusion: What is the Average Cost of a Deck per Square Metre in Australia?

On average, expect to pay $100 per square meter for decking materials. However, the cost of an installed deck could be double or triple that amount depending on the deck design and labour costs. Most builders offer free quotes. Try to get a least three to compare.