Ask An Expert

WoodSolutions doesn't engage in R & D projects, but our 'parent' organisation, Forest & Wood Products Australia (FWPA), is one of the bodies that supports Australia's National Centre for Timber Durability and Design Life. You can log onto the Durability Centre's website via this link https://research.usc.edu.au/esploro/research-units/61USC_INST___24?institution=61USC_INSTExternal link. 

You might be thinking of a 4-part webinar that was promoted by WoodSolutions but actually hosted by Timber Queensland in 2022. A fee applied to take part. We understand it is no longer available, although you could check with Timber Queensland in case they have other resources. We have a 3-part webinar that is still accessible and free of charge. You can log in via these links https://www.woodsolutions.com.au/webinars/woodsolutions-tuesday-webinars/as1684-series-part-1-general-usage-and-applications, https://www.woodsolutions.com.au/webinars/woodsolutions-tuesday-webinars/as1684-series-part-2-bracing-afzal-laphir, https://www.woodsolutions.com.au/webinars/woodsolutions-tuesday-webinars/as1684-series-part-3-tie-downs-and-connections. 

If the blackbutt screen is required by regulations to prevent embers from accumulating under the floor, the screen would have to be a lapped cladding profile with sub-floor ventilation openings protected with mesh. Fixings would be to suit the cladding profile. Alternatively, 70 x 30mm timbers could be spaced apart with mesh protecting the gaps. The mesh must be corrosion-resistant and have a maximum aperture of 2mm. These requirements only apply if the house floor is less than 400mm above finished ground level. If the screen is not required to prevent embers, ie. the floor is more than 400mm above ground, or protected in a different way, a size of 70 x 30mm in kiln-dried blackbutt should safely span up to 2.1m. For best results use 4.2m lengths over 3 supports.