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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?

Q. I would like to discuss possible longer term impact of turpentine tree root system of mature tree ( 30 + m) located close to house Could you suggest someone I could speak to?

The impact of tree roots on buildings depends not only on the species of tree and how aggressive its root system is, but also on the soil type and local climate. For example, in dry weather trees may cause clay soils to shrink by withdrawing moisture. Tree roots also seek out sewerage and stormwater pipes, sometimes completely blocking them. Publications by various authorities explain these issues in more detail. SA Water has prepared a Tree Planting Guide which explains some of the issues and the guide can be downloaded at CSIRO also published Information Service sheet no. 10-75 in the 1980's titled "Trees & Foundations" which you might be able to obtain. Neither publication mentions turpentine (Syncarpia glomulifera) as a "species to avoid" but this might just be because it's not commonly planted in gardens or streets. The CSIRO data sheet points out that the greatest danger occurs when trees are planted after construction. The water demand of a tree increases with age until it reaches full maturity - it's less likely that an existing mature tree will cause damage to a new building nearby. If you need to discuss this further it's possible that the Botanical Gardens in your capital city provides an information service.

Q. We are looking for a structural ply wood suitable for use in a university workshop and a laboratory that works with ice cores in a constant freezer at minus 20 degrees. The products we have had recommended include Glulam and Tasmanian Ash structural Ply. Could you please have a rep contact me on the below details. Apologies but our query is also urgent.

Freezing wood doesn't have a significant effect on its properties, although frozen wood that is subsequently dried can show a slight decline in strength. A more significant effect would occur if the wood was exposed to cycles of freezing and thawing, particularly if it was simultaneously gaining and losing moisture. However, it seems that the materials in this case will be exposed to a constant temperature of -20°C, so moisture cycling is unlikely to occur. Having said that, glulam and plywood are both glued products and we are not sure what effect prolonged exposure to sub-zero temperatures will have on the glue. We would expect phenolic-type glues to perform satisfactorily, but emphasise that we do not have a specialised knowledge of the properties of adhesives. It is possible that the Engineered Wood Products Association of Australasia (EWPAA) might be able to advise you further. They have a website at

Q. We engineer, produce and build wooden houses in Brussels, Belgium. I am looking for colleagues in Australia. Can you send me some names and addresses?

A company called Alternate Dwellings has a range of timber kit homes with displays and agents in several parts of Australia. You can find out more about their operations from their website at

Q. We are working on the Olympic Dam Project for BHP and have a requirement for your product. Could you share the right contact person so we can pass on the RFQ?

We weren't sure which product you were referring to. This website provides answers to technical questions about wood products, but we don't sell or supply any products. If you feel we can be of further assistance please feel free to leave another message.

Q. I'm currently working on a commercial project and want to specify American White oak for an Internal Feature wall panel. The size of timber panels specified are 75mmx25mm can you recommend a supplier of this product. Also the finish needs to match the flooring selected, can this product be Lime Stain?

We are not sure where your project is located, but Austimber have American white oak in stock in Sydney or their Melbourne agent could get it down for you if the project is in Melbourne. You can phone Austimber on (02) 9627 5001. American white oak takes a stain well, but that would normally be done on site, not by the timber supplier. If the timber is likely to come into hand contact it would be best to seal it with a clear lacquer after staining to provide an easily cleaned surface and prevent it from becoming grubby.

Q. Hi there, How long do you take to reply to a question? Thanks - Steve

Generally we can get an answer back within 24 hours, sometimes a bit longer depending on pressure of work.

Q. I wish to sell large numbers of Hoop Pine display shelves located in Boisens Drapery Store Wondai Queensland. Most of the shelves are from 6 to 8 metres long, and from 31cm to 45cm wide. All are 2.3cm thick. Planks of this width are rare today. The display shelves have stood against the walls of Boisens Drapery Store since the 1920's. The recycled timber will have nail damage but is still perfectly aligned, magnificent to the eye and to the touch. Please advise how I may obtain a proper market price for these shelves and avoid being ripped off.

It's very hard to advise you on the value of your hoop pine - as with real estate, its value is what someone is prepared to pay on the day. You could get an idea by contacting some timber recycling businesses, eg. Kennedy's in Brisbane. Rather than asking how much they would give you, ask how much it would cost to buy recycled hoop pine in those sizes. A timber merchant would probably not be able to quote a price as no-one is likely to have those lengths and widths in stock. Nevertheless, a specialist timber merchant might be able to quote a price per cubic metre for seasoned hoop pine. Failing that, you might find a cabinetmaker or woodworking hobby group in your area that is interested in buying this material.

Q. Our house in Sydney was extensively damaged by fire in November 2011. Since then it has had no roof. It has a timber floor supported on hardwood bearers and joists with a subfloor space ranging from 450mm to 1500mm in height. The subfloor is now saturated from all the rain entering. The bearers and joists are saturated and have white and green mould over them. It seems to me that the bearers and joists will be decaying due to being wet all the time particularly at timber to timber joints. It seems reasonable to me to request that these be replaced rather than have a new floor fixed down to possibly compromised timbers. Also that the new timber floor isn't laid until the subfloor is dried out again. The insurance company disagrees at the moment. Are there any industry guidelines or precedents that I could show them to support my case?

There isn't any real likelihood of decay just yet - it takes a lot longer than three months for wood rot to begin, although the presence of moulds shows that there is enough moisture there for fungal attack to occur if left unchecked. A typical pattern in the breakdown of wood is: colonisation by stain fungi, followed by moulds, followed by white or brown rotting fungi. Stains and moulds have no effect on strength and are essentially a surface effect. However, there are several issues in relation to your floor. The bearers and joists must be allowed to dry thoroughly before a new floor is installed on top, and the ground under the floor must also have a chance to dry out. The bearers and joists are likely to dry more quickly than the ground under the floor, since they are suspended in the air. If new flooring is installed too soon over earth that is still wet, the floor may swell. On the other hand, it is possible to control moisture rising from under the floor by installing polyethylene ground cover (same principle as the vapour barrier under a concrete slab). You can find out more about this technique by writing the words "polyethylene ground cover" in your browser. It seems to us that the most important issue is to reinstate the roof as soon as possible while still keeping the house open enough for drying to continue. While the bearers and joists are not at any real risk of decay yet, leaving them in place to dry naturally may extend the re-building time beyond an acceptable limit. You might prefer to have new bearers and joists installed, with soil cover in the subfloor space, in the interests of speeding up the re-building process, rather than waiting for the original timber to dry out. If your insurance company maintains that the bearers and joists have to stay in place, it will be necessary for someone to test the timber at intervals with a moisture meter to monitor the drying process. And we would still feel that ground cover in the subfloor space is a good precaution, even if the soil looks dry, given the amount of wetting that has occurred.

Q. My father & his brothers had a saw mill in the new england area of nsw, which has ceased operation several years ago. There is a pile of timber which dad would like to maybe split into smaller pieces and sell.

There are a couple of options. You could contact a few timber merchants who supply builders and see whether they are interested in your father's timber. Perhaps do this before he saws it into smaller sizes, to make sure they are the sizes that the industry wants. The other option is to put it on one of the internet sites (eBay, Gumtree, etc) and see whether there any takers.

Q. In late 2010 I cut down a silky oak in our bachyard ( Forestville 2087) It was VERY roughly cut into slabs with a chain saw . There are 5 slabs about 1.8m long about 70mm thck (variable) and up to about 400mm wide . They have been seasoning for about 12 months . The timber looks like good solid silky oak in texture and grain . I would like to have them milled into usable timber -- preferrably slabs . Is there someone around my area who would do this and what would be the rough order of cost?? . Thank you Toby Rose

We are not aware of anyone who is specifically set up to do this but it may be worth contacting a TAFE College nearby that may have access to planing machinery.  Otherwise contact a local joinery or small furniture manufacturer.


Did you know?

About 16% of Australia’s 147 million hectares of native forests are in nature conservation reserves.