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Logs from plantations cannot produce the sawn hardwood timber produced from logs currently harvested from native forests.

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Like to know what wood to use building a pergola or framing a barn? How about the difference between tung oil and polyurethane as a floor finish? How to revive decking or deal with merbau stains? Or how to meet the building code or bushfire standards? or ask about the environmental advantages of wood or forest certification?

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Q: Spotted Gum Cladding: is the cladding manufactured or milled from the heartwood or sapwood part of the timber? Is it possible to specify/order the cladding to be specifically "heartwood"?

23/04/2013

Spotted gum cladding should only be milled from heartwood, unless the timber is preservative treated. While the heartwood is rated Durability Class 1 outdoors above ground, the sapwood is non-durable and subject to borer attack. Consequently it should either be eliminated or preservative treated. The sapwood can be easily recognised since it is white in colour, while the heartwood is light-brown to dark brown. Your supplier should be able to advise whether the cladding is all heartwood or, if not, whether it is preservative treated.

Q: I'm working on Charles Sturt University & GOTAFE project on Wangaratta Regional Campus. We have mainly Stramit metal cladding to external walls, however, we do have a featured external wall which we would like to use sustainably sourced hardwood cladding. Timber cladding could be fixed to top hats or timber battens with steel stud frame as substrate. I would like to know which company in Sydney or local area around Wangaratta to contact. Your advice would be much appreciated.

23/04/2013

Radial Timber Sales produces weatherboards from silvertop ash, using a technique specially developed to maximise recovery from small logs. The environmental benefits of this process are described on their website at http://www.radialtimber.com/environment.html. Boral Timber also produces weatherboards from locally-grown hardwood and you can find out more from their website at http://www.boral.com.au/ProductCatalogue/product.aspx?product=2256. Finally, don't overlook "Weathertex", an Australian-made reconstituted cladding material made from sawmill waste and forest thinnings. For more about this product visit their website at http://www.weathertex.com.au/about.php.

Q: Please advise where to source treated plywood for exterior cladding in Melbourne.

18/04/2013

One of the major treated plywood cladding products is "Shadowclad" produced by Carter Holt Harvey. If you write the name of the product in your browser a number of suppliers will come up. There is also lots of information about "Shadowclad" on the Carter Holt Harvey website.

Q: Thinking about using a hardwood timber shingle but would like to see one on display it is for our pergola on pool area - we like that old look. Please advise if you know any suppliers of hardwood shingles.

14/04/2013

The only company we know of that currently produces Australian hardwood shingles is Aussie Shingles. They have a website at http://aussieshingles.com/advantages.html  where you will find contact details.

Q: I am demolishing an old 100 year old house. I was interested to know if the hardwood timber external cladding could be reused as timber decking?

09/04/2013

Ideally we ought to know the type of timber before making a recommendation about its suitability for decking. However, if it has lasted for 100 years exposed to the weather as external cladding, and is still in good condition, we assume it is a durable species. If you feel past performance doesn't give you adequate assurance, it is possible to have a sample identified. We could then give you a more positive recommendation. A specialist in wood identification is Dr. Jugo Ilic. He can be contacted by email at knowyourwood1@optusnet.com.au.

Q: Our architect has proposes vertical timber cladding for our new house in Geelong Vic. Cladding will be on west and south facing walls. It is likely to be a ship lap type profile. We have concerns that with vertical cladding there is less resistance to ingress of water. In particular we are concerned with water ingress between the two layers of timber at each joint. Are you aware of any guidance or research materials relating to this subject please?

06/04/2013

It's good practice to install "sarking" behind timber cladding to ensure the building stays watertight, particularly at times of wind-driven rain. The architects are probably aware of this, but you might want to direct them to a timber industry website that explains the issue in detail. Information can be found at http://oak.arch.utas.edu.au/tbia/view_article.asp?articleID=203.

Q: Just wanted to know if an H2S timber (specifically Red Alert) would be suitable to use in an outdoor deck? Or would I require H3 or higher.

31/03/2013

Tilling Timber's H2S treated timber would only be suitable for a deck if the deck was completely enclosed and not subject to rain wetting. In fact the Tilling website at http://www.tilling.com.au/smartframe/red-alert advises that H2S Red Alert "is not an external product and should not be used for decking situations". The reason is that H2S treatments only provide protection against insect attack, not wood rot. So you would require H3 or higher for a weather-exposed deck.

Q: I am using Merbau decking 140mm wide x 19 mm thick to fabricate steps. These will be exposed all weather & in particular the afternoon sun. The end of the lengths of timber will overhang the supporting bearers by about 100mm at each end. I was planning to leave the timber untreated for a while (so it fades a bit) - then use some sort of preservative oil to help reduce weathering & water ingress. Is it likely that the unsupported ends will split over time ?? Will the use of a wood preservative help prevent this ?? Is there anything else I can do to reduce the possibility of the ends splitting ??

26/03/2013

The reason why timber sometimes splits at the ends is because moisture moves in and out of the ends more readily than through the sides. It commonly happens when green timber with a high moisture content is placed in dry, uncontrolled conditions. End-splitting should be minimal in kiln-dried timber, even outdoors, but to reduce the possibility a coating on the ends of the boards will help.

Q: We currently have a concrete porch and wish to extend with decking. Is it possible to lay the floorboards over the concrete? How to we prevent water damage? Thanks for your time yet again.

23/03/2013

Perhaps the porch area is protected so water won't collect on the concrete when it rains. If not, allowance must be made for water to drain away. Our concern is the effect the water may have on the decking boards. If decking is suspended close to water it's likely to absorb moisture on the underside and "cup", ie. curl up at the edges. We also weren't sure whether there is enough space to install joists on the concrete and fix the decking to the joists, or whether you wanted to fix the decking directly to the concrete. If the decking is on joists, we suggest trying to sit the joists up a bit above the concrete by supporting them on spacer blocks of fibre cement or a similarly inert material. This will allow water to drain freely between the joists and prevent the undersides of the joists from being damp for prolonged periods. If you intend to fix the decking directly to the concrete it is important that no rain enters the porch area. Placing strips of damp-course under the decking would be a good idea, even if rain doesn't enter the porch, to protect against damp rising through the concrete from the ground.

Q: I am currently having a jarrah timber deck built and are getting conflicting advice regarding when to apply decking oil to protect the timber. A guy at Bunnings said to wait 6-8 weeks to allow the timber to bleed out tanins and oils during rain periods (also water it with a hose if it doesn't rain) and then apply a decking oil. While my builder says I should apply it as soon as the deck is constructed as the timber will potentially expand, buckle and fade as it takes on moisture. What's the correct time to apply decking oil to a jarrah deck? Thanks Regards Greg

14/03/2013

Some say decking should be weathered for a time so the oil can penetrate better. This might be based on the idea that freshly planed timber has a glazed surface (mill glaze or planer's glaze) that prevents absorption of the oil. Research bodies have been unable to duplicate mill glaze in the laboratory, but you will find more information about it if you write the words "mill glaze" in your browser. Others say timber should be coated as soon as possible, before UV affects the surface and the natural colour starts to weather off to grey. We are inclined to the latter view, ie. coat it straight away. If it's a hardwood that is likely to leach tannin, such as jarrah, a preliminary scrub with a deck cleaning product is worthwhile before you apply the oil. This is not something we've tried ourselves, but it's recommended by the finishing companies to remove excess tannin. Apart from that, we don't think there's any need to delay coating it.