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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. Looking for a measurement device or methodology or person who can measure the reflectivity of timber. Would like to know as we are putting some timber behind glass and the Architect wants to know the reflectivity of the facade.

We don't know of an Australian Standard that sets out a methodology for testing reflectivity, but there is a British Standard that does so. It is BS8493:2008+A1:2010A "Light reflectance value (LRV) of a surface. Method of test". The test method produces an LRV on a scale of 0 to 100, where a result of 0 is a surface that perfectly absorbs all light (assumed to be totally black) and 100 is perfectly reflective (and can be considered totally white). You can read more about this in an information sheet on the net at Note that timber exposed to direct sunlight behind glass will undergo considerable colour change, even if coated with a UV absorbing coating, so that an initial LRV is likely to change over time.

Q. After some information on timber spectral data. Reflectivity, emissivity etc. Where can we obtain this information? Are there companies in Sydney that will measure this?

We don't know of any companies that specialise in measuring reflectivity, but if you contact the National Association of Testing Authorities (NATA) there is likely to be a NATA-accredited laboratory in Sydney with the necessary equipment. Of course the reflectivity of timber will vary considerably depending on the species of timber (dark or light colour), the surface finish (rough-sawn or planed) and the type of surface coating (matt or gloss), so all these factors will need to be defined.

Q. I after some information on Rosewood. I do not know if you are able to answer these questions or could recommend someone who can. I have installed rosewood boards to a ceiling and installed some Thermofilm Heaters to it and am after some advice. This advice could be used as expert advice. The heaters give off a radiant heat to the boards and during operation also leave a carbon residue on the wood as well which is able to be wiped off with a moist cloth. My query is what is the level of heat (eg 50,75,90 degrees) and for what period of time is the wood able to absorb it prior to it damaging the wood(drying it out and cracking it etc) and would the carbon on the wood damage it at all?. I am after this information as the manufacturer of the heaters claims it will not damage it at all and I am sceptical of it.

Heat applied to wood will dry it out unless humidity is maintained at a high level. If your ceiling is exposed to relatively low temperatures for prolonged periods the main effect is likely to be shrinkage, depending on how dry the wood was to begin with. If the timber is exposed to sudden temperatures in the higher range it might also split. It's difficult to give you a precise answer. We are not familiar with Thermofilm Heaters but information on the net suggests they are ceiling mounted, radiating heat downwards, in which case heat is not directed at the wood and it would only experience the warmth of the surrounding air. In fact a photograph on the Thermofilm website shows their heaters mounted on a timber ceiling so presumably they have some experience of the likely effects. We can only suggest you seek information from Thermofilm - perhaps they have some test data or field studies that would reassure you.

Q. Best place around central coast to find instrument grade quarter sawn timbers?

We suggest you try Trend Timbers at Mulgrave. They have some instrument quality wood in stock, eg. rock maple, blackwood, rosewood and so on.

Q. Have you ever worked with termite infested wood? If so, could you tell what it looks like in pics? I have pics of wood that I suspect is termite infested but I really need an experts advice. Please email me and I will be willing to send you the pics I have.

There are three major enemies of wood, termites, borers and rot, but they all damage wood in different ways. Termites don't like to be exposed and so tunnel through wood in galleries. The wood they leave intact is not softened but retains its structure and hardness. There are lots of images of termite damage on the net and you will find them if you write "termite damage images" in your browser. Maybe there will be some images there that are similar to your pics. Borers cause quite different damage leaving holes of various sizes when they emerge from wood, usually associated with borer dust nearby. Wood rot is different again, leaving the wood soft and stringy, or crumbling, whereas termites actually consume some of the wood but generally leave adjacent wood untouched. Wood rot only occurs when wood is damp and while termites are attracted to damp wood they can also attack dry wood.

Q. We are currently working on a university project where the architect wants to use solid Tas Oak timber benchtops in a -20 degree freezer. The benchtops will be supported by stainless steel frames. How will the timber perform in this environment? What adhesive would we use to laminate the timber? What would we use to finish the timber tops?

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 in a constant temperature of -20°C, so moisture cycling is unlikely to occur. Mawson's huts in Antarctica are a good example of the performance of timber in sub-zero temperatures and although they are looking a bit tired now they have been there for 100 years. Laminated benchtops are a glued product and we are not sure what effect prolonged freezing will have on the glue. We would expect phenolic-type waterproof glues to perform satisfactorily, but emphasise that we do not have a specialised knowledge of the properties of adhesives. Maybe the Engineered Wood Products Association of Australasia (EWPAA) could advise you further. They have a website at Regarding a finish, we suggest a water-based floor varnish, although it is not essential to apply a finish in this situation.

Q. I am trying to find an Australian supplier of wood veneer sheets in a thickness of 1.00 to 1.2 mm. All the suppliers I have contacted to date seem to only produce veneer sheets in a thickness of 0.6mm or 2mm. Do you know of a supplier who would be able to supply sheets in this particular thickness or could custom produce them ?

We understand that Briggs Veneers in Sydney stock this thickness specially for skateboard manufacture, but we don't know of other suppliers. If you are in some other part of Australia we can only suggest you try one of the major veneer merchants with a branch in your State, such as Amerind, Laminex, etc. Even if they don't stock that thickness they might be able to order it in for you. For contact details, visit the Timber Veneer Association's website at

Q. I would like to know how to make a sound proof room in which I can play my drums. The room is going to be constructed in an existing shed. The size of the room is going to be 6 metres X 3 metres X 2.4 metres high with 1 door access only.

It's difficult and expensive to completely soundproof a room, but if it's in a shed that is removed from the house, that's a good start. Wood products on their own are not going to be a great help, but timber stud walls can be designed to be quite good sound barriers in conjunction with other materials. The best system is a double wall (separate studs and top and bottom plates). Sound is then transmitted into the wall cavity by vibration of the internal lining, but is not transmitted so readily through the stud frame and out the other side. Further improvement is achieved by placing insulation in the wall cavity, and fixing the plasterboard with resilient channels rather than rigidly attached to the wall frame. Special denser-than-usual plasterboards are available for acoustic use, eg. Gyprock "Soundchek". For more information paste this address into your browser: Note that the door will be the weak link in the whole system and you will need to consider (a) using a solid door rather than a hollow door, and (b) installing acoustic seals around the door opening if you want to do a thorough job.

Q. We own a business in China specializes in making MDF, currently we are using local eucalyptus which has high growth rate, to reduce the cost, we are looking to import some softwood chips from Australia . Would you please recommend which species from Plantation is suitable for our needs, and where can we find the suppliers?

The most readily available plantation softwood in this region is pine and we will send you a list of Australian pine producers by separate email. New Zealand producers should not be overlooked, and they can be sourced on the net, eg. Tenco who have a website at, along with others.

Q. We are looking at selling a number of karri trees we have on our property that require clearing. I am trying to work out the m3 volume of the logs as that is what we have been quoted by a mill to purchase the saw logs. I have done a bit of Googling this answer but am still confused as there seem to be a number of methods used around the world. What is the standard in Australia? What seems to be go is: pi x radius x length = m3 Volume so if I have a log 0.33m radius and 5.1m long 3.142 x 0.33 x 5.1 = 5.28m3 Is this correct?

There are many different systems used around the world for calculating the volume of logs. Some methods attempt to calculate the quantity of marketable timber obtained from the log by making an allowance for waste and taking measurements under the bark. Maybe you should ask which system the mill uses that is quoting to buy the logs, and then follow their instructions. In the absence of any advice from the mill, the simplest way to calculate the volume of a log is to measure the radius each end, average the two (since there will be some taper towards the top) and calculate the volume as if it were a cylinder. Your calculation is on the right track, but the formula for the volume of a cylinder is πr² x length. So your example would be (3.142 x 0.33² x  5.1) = 1.75m³ (assuming 0.33m was the average of the two radii each end).


Did you know?

A government report showed there is no evidence proving that harvesting timber from native forests has reduced overall forest biodiversity or led to the extinction of any species of plant or animal.