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Wood species & their properties

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. As part of the Centenary of Anzac, I'm restoring a World War One army wagon . One part of the wagon was made in the UK, while another part was made in Australia; It is dated 1915/16. I need to replace parts of the original load carrying box. Early references say that "deal" was used in the original construction. Am I right in assuming this was pinus sylvestris (Scots pine) in the UK? What would be the Australian equivalent of "deal" back in 1916 and where could I purchase some today?

We are not sure of the origin of the name "deal" but you are right in thinking it is another name for Scots pine. More precisely, Scots pine (Pinus sylvestris) is known in the UK as red deal, while European spruce (Picea abies) is known as white deal. In 1916 deal would most likely have been imported, rather than substituted by a local wood. Today these timbers are known in Australia as Baltic pine, either red Baltic or white Baltic, their main use being floorboards. Red Baltic tends to be preferred for floorboards since the heartwood has a little more colour, as the name suggests, whereas white Baltic is more uniformly pale.

Q. I NEED ASSISTANCE REGARDING THE INTERIOR FIRE RATING OF HEMLOCK (one of the Canadian Spruce varieties) the Timber.net.au site covers a few under this heading. Specification C1.10a Fire Hazard Properties: Wall and Ceiling Linings/Coverings It does not cover Hemlock. Can any one help with a rating/ group number?

Unfortunately hemlock has not been tested assess its fire hazard properties. Actually Specification C1.10a no longer exists - Specification C1.10a was incorporated into Specification C1.10 in the 2011 edition of the BCA and requirements for wall and ceiling linings are now set out in Specification C1.10. It's likely that hemlock would be rated Material Group 3, along with other commercial timbers, including low density species such as western red cedar. However, in the absence of testing this can't be confirmed.

Q. Where I can obtain gurjan wood for export other than Asia.

Gurjan is a trade-name or local name for wood from a very large group of Dipterocarpus species, more commonly known as keruing in the Australian market. But these species don't grow anywhere in commercial quantities except in South-East Asia, including Malaysia, Indonesia, Philippines, Burma (Myanmar), Thailand and Laos.

Q. I am looking to clad some 90x90 steel structural posts with timber for aesthetic reasons. The timber thickness will likely be around 25~30mm resulting in a finished post thickness of around 150x150. What type of timber should I consider using to meet criteria of stability, durability and affordability. It is desired that the finished colour roughly resembles cedar.

We assume the posts will be exposed to the weather and if so would recommend western red cedar. For your purposes you need a timber that is highly dimensionally stable and cedar has that quality. It will also satisfy your colour requirement. There is a company that specialises in cladding steel posts and you can visit their website at this address: http://cedarwest.com.au/column-claddings. If engaging a builder to do it, make sure the cladding is joined in such a way that minor movement won't open the joint. For example, mitre joints look neat but the slightest movement in the timber opens the mitre.

Q. I'm going to be building a cider press, directions call for hardwood with oak and maple being suggested. I have walnut available and am wondering about its suitability for something that will be getting wet.

Walnut is quite a durable wood and will tolerate intermittent wetting. As far as we are aware it doesn't have a strong odour that would taint the cider, although we are not familiar with the use of walnut in contact with foodstuffs. But presumably cider isn't stored in the barrel of the press, like wine in oak, so it would only be in short-term contact with the wood.

Q. I am looking at retro fitting an old bus with your flooring as well as building bench tops (and possibly benches, provided it's cost efficient to do so). I am looking for a wood product with a high fire resistance as I am making a mobile watch/jewellery repair bus where soldering and using a little torch (butane gas torch). Pieces of hot jewellery/solder may actually fall on the floor. So I am trying to eliminate the threat as best as possible. Can you please advise me on your recommended product. I would need at least 30 square meters of it to cover the floor and bench tops only. But if cheap enough I may make the entire benches with it.

The denser the wood the greater its resistance to fire, so we suggest one of the heavy hardwoods. Ironbark would be a good choice. It's not the cheapest flooring on the market but will be very serviceble. It might be worth looking in recycling centres before purchasing new wood in case recycled floorboards are available.

Q. I have a wood tongue and groove ceiling and want wood ceiling registers. The color of the ceiling is 'Expresso' over pine, making the color a medium tan or yellowish tan. It has been suggested that, due to the humidity here in Florida, I have the registers made of teak. However, the color of teak does not match well. Can you recommend another wood that, either in its natural state or stained, will better match my existing ceiling's color while resisting warping?

It sounds as if western red cedar might be a good match for your tan-stained pine. It is naturally a medium tan colour without a stain and is very stable, so it should stand up to the Florida climate without warping. Maybe you could get a sample of cedar to see how it looks against the pine.

Q. We are wanting to do our own Shou-Sugi-Ban can you tell me if there is a suitable equivalent timber in Australia for Japanese Cedar?

Shou sugi ban is charred sugi wood (Japanese cedar). However, charring can be carried out on any species, preferably a softwood with prominent growth rings. Japanese cedar is similar to Californian redwood, or the more readily available western red cedar. Charring a softwood such as western red cedar allows the softer portion of the growth rings to be brushed out leaving the harder part of the growth ring raised, resulting in a textured surface. If you want to try it yourself the process is described on this website - http://pursuingwabi.com/2007/11/05/shou-sugi-ban/.

Q. We are currently restoring a 6 man row/sailing boat clinker built We have the oars but would like to reestablish the boat as a sailer. The boat is 18ft long. What timber is available in Tasmania to make a mast and spars. The boat is made from king billy pine as far as we can tell. Regards Ron Wells Coordinator

King Billy pine is good for general boatbuilding but perhaps not strong enough for the more stressed components such as a mast and spars. Celery-top pine is some 40% stronger and would be a better choice if available in a suitable size. Compression wood, which has lower strength properties, is sometimes present in celery-top so try to source your material from straight trees with even growth rings.

Q. I have been asked to look for wood supplier in Sydney for a type of ash. However, I am not too sure of the specific type it is. I have given 3 photos, I am wondering whether there is anyone who could work it out from the photos?

It's hard to tell from your photos, although the log looks like some kind of ash. However, a positive identification can be made by examining a sample microscopically. Each species has a distinctive cell structure and specialists in this field use such characteristics to identify different species. A noted expert is Dr. Jugo Ilic whose consultancy is called Know Your Wood. For details of fees and required sample size send an email to knowyourwood@gmail.com.

WoodSolutions

Did you know?

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