Timber Decking in Bushfire Prone Areas
The appeal of natural elements in home design is enduring and, according to Boral Timber, Australian timber remains one of the most desirable materials for domestic deck and verandah construction. To minimise the risk to property during a bushfire, homeowners, builders and landscaping professionals should consider a number of design and landscaping rules and year round maintenance measures.
Dominic Adshead, GHD Senior Consultant – Bushfire Management, advises "New structures must comply with the requirements of the Australian Standard (AS3959 -2009) Building in Bushfire Prone Areas. However, as part of wider property protection measures, there are a number of steps you can take to protect your existing verandah before and during the fire season to reduce the impacts of direct flames as well as wind driven embers that may be carried significant distances.
"Landscaping around decks and verandahs, for example, plays a significant role. Shrubs planted adjacent to a house or structure in a fire act as 'ladder fuels', allowing a ground fire (burning in grass or woodchips) to travel up into the shrub and then into the wall or roof of the house or structure. These plants should be trimmed back or removed, particularly those next to an opening such as a window," states Adshead.
- Keep your verandah well maintained by sealing timber with a non-combustible seal.
- Fill in small gaps around the deck structure where an ember might be able to lodge - larger openings can be fitted with ember guards (such as perforated mesh with 2mm openings).
- Check that decking is spaced at around 0 - 5mm; gaps of 5 - 10mm have been shown to be particularly vulnerable to ember attack1.
- Remove leaves and twigs from the roof and gutters.
- Enclose the subfloor of the verandah using mesh or bushfire resisting timbers; Boral Timber recommends species such as Blackbutt and Spotted Gum.
- Flammable shrubs and woodchips, that in the event of a bushfire will become fuel, should not be used for landscaping immediately adjacent to the deck; decorative stones and more fire resistant plant species could be substituted.
- If in any doubt contact your local fire authority for more information.
"In 2012, fires in the eastern States are most likely to be fast moving grass fires as the heavy grass cover that has grown following a wetter period dries off," said Adshead. "However, the west of Australia is subject to a significant drought and forest fires are more likely in this region. In any case, property protection measures should be maintained before and during the fire season. In south-east Queensland preparations should commence as early as August 2012. Late 2012 and early 2013 is a particular concern in this area as historically larger grass fires have occurred one to two years after significant floods."
Boral Timber recommends Australian hardwood species for the building of decks and a variety of other exterior home improvements, because of their high density, toughness and durability. Boral has also achieved Australian Forestry Standard (AFS) chain of custody certification (AS 4707-2006) for its timber products. This means that timber used to produce Boral Timber's hardwood flooring, decking and structural timber has been sourced from certified, legal and sustainably managed resources. The Australian Forestry Standard Scheme also has mutual recognition by the Programme for the Endorsement of Forest Certification Scheme (PEFC) - the world's largest forest management certifier.
1Derived from AS3959-2009 (Construction of buildings in bushfire prone areas) - Clause 5.7.1
>Busfire Protection - Plasterboard & Timber Systems
>Construction in Bushfire Zones Brochure
>Timber Decking Product Catalogue
>Boral's AFS Chain of Custody Certification