Timber Decks

The quality of modern timbers is nothing like what was available 50 years ago. Whereas we used to confidently predict the lifespan of a hardwood deck, that is no longer the case. The number of decks using a timber board is declining rapidly due to the other feasible options now available.

That being said, we still get asked to construct the occasional timber deck. If you decide timber is for you, this information may assist in your decision.

It is recommended that when a Deck is less than 300mm above the substrate, the boards should be a maximum of 90mm wide and have a minimum 6mm gap between the boards. Decks should have a minimum 100mm of airflow under the substructure. It may be worth considering an alternative product if these conditions cannot be met.

Commonly used timbers for deck boards

Most commonly used hardwood. Deep red-brown in colour, extremely durable, high initial tannin bleed. It is a Class 1 hardwood and fire rated

Similar to Merbau, but cheaper and not as durable. Non-leaching, Light reddish brown, great grain. Class 1 hardwood

Natural Australian Timber that tolerates harsh weather conditions well. The colour variations range from light hazel to deep red with a distinctive wavy pattern in the grain.

Strength and durability similar to Merbau. Class 1 and fire rated.

Strength and durability similar to Merbau. Golden yellow to pale brown, sometimes with a slight pink tinge. Noted for its resistance to moderate bushfires.

Class 1 and fire rated.

Merbau: 90 and 140mm wide

Balau: 90 and 140mm wide

Spotted Gum: 86 and 136mm wide

Blackbutt: 86 and 136mm wide

Pacific Jarrah: 90 and 140mm wide

Very Durable and non-leaching hardwood. Vibrant red-brown in colour. Class 1 hardwood

Northern Box: 90 and 140mm wide

Very Durable and hard wearing hardwood. Vibrant red-brown in colour. Class 1 hardwood

Treated Pine: short lifespan

One of the most popular decking timbers because it is one of the least expensive options and can make a great looking deck. Pine takes stain or paint well, so you can make your deck any colour you like. The two main advantages of using treated Pine decking are: low-price and consistency that runs through each piece of the timber. – Not good for low level decks