A wake-up call for the framing industry and builders alike
An Australian softwood producer has recently made a bold move towards H2 Blue treated structural timber as a minimum. Find out what’s spurred the move – and why the industry as a whole should be paying close attention.
Ddebate about just how durable and resistant to insect attack timber framing should be has been going ever since the first white settlers in Australia built some kind of shelter. I suppose insects or decay weren’t a problem when the shelter was nothing more than just that – and if it fell over, you just built another one.
As time passed in the colonies and shelters became houses, owners wanted to make sure they lasted, and the builders were expected to use materials that did the job properly.
In the early years, hardwoods were all they really had. Country NSW and Queensland also used cypress, but availability was generally limited to its region of supply, and because most houses were built in the coastal cities, hardwood was the main resource. Over time, building regulation came into being – firstly in regional locations, then in the individual colonies. Regulations became statewide as states were formed, and eventually the Building Code was established.
Hardwoods apparently did the job in most of Australia, although by the end of the 19th century both Sydney and Adelaide had become very softwood oriented (particularly towards Douglas fir / Oregon out of North America). Different rules and regulations developed in all jurisdictions.
Durability’s always a major factor in building, but when it comes to timber framing – which is mostly protected from the elements – insect attack and how it affects timber’s structural capacities is the paramount concern. Sapwood from any timber – regardless of a species’ durability rating – isn’t durable, and is usually susceptible to some form of insect attack.
It soon became apparent that two insects could cause widespread damage to timber, particularly in house frames where they can go about their destructive ways seemingly without detection. These two insects were termites (of which there are many different species with varying appetites), and the Lyctid Borer.
Termites are by far the most destructive of the two. Although most species of termite favour sapwood (it’s easier to chew) and timber with a higher moisture content, just about all species of timber – whether seasoned or not – are potential sources of cellulose. The high density, high durability species and those with a high silica content suffer the least incidences of attack, and only the truewood (heartwood) of Australian Cypress appears to be immune.
As building codes and regulations appeared, restrictions to limit insect attack became more stringent – but it wasn’t until the middle of the 20th century that various state forestry departments legislated to restrict the use of timber which is susceptible to various types of insect attack.
Common building practice had been to use barrier systems to deny access to termites. That practice has continued through the various state ordinances, standards and codes, and is still used today. Borers are a different matter though – barriers are totally inefficient against borers, and some form of treatment is really the only method to control them.
NSW and Queensland legislated to control the amount of Lyctid-susceptible sapwood that could be included in framing timbers and as such, a lot of the susceptible hardwood was treated (only hardwoods are susceptible to Lyctid). Back in the heyday of unseasoned hardwood framing, it was very difficult to identify the sapwood from the truewood – and with a lot of the small end-section framing sizes cut from the ‘wings’ of the log, sapwood was very prevalent.
The hardwood producers were forced, by the action of government legislation, to make sure their framing materials were in fact ‘fit for purpose’.
This is not a position that the softwood sector of the industry has addressed. The industry as a whole has lobbied code makers to adopt the ‘whole of house’ principal, arguing that not only is it the frame of the house that’s susceptible, but all the other cellulose-based fixtures and fittings (the paper on the plasterboard, carpets etc.) and for that reason houses should be constructed in such a way that the threat is built out.
That’s probably good building practice for the purpose of preventing attack by subterranean termites, but it does little to control airborne termites or borers.
In the mid 1970’s, Keith Bottle – then a researcher at the NSW Forestry Commission and author of several timber industry textbooks including Wood in Australia – surmised that with Australia moving towards the use of plantation softwoods (radiata pine in particular), at some point in the future there was the likelihood of a large scale attack by the Anobium borer.
At that point Anobium wasn’t well known in Australia. This borer mostly attacks the sapwood of softwoods, and it wasn’t considered to be a major threat because the only understood infestations had occurred in furniture (also known as the ‘furniture beetle’), and in baltic pine products like flooring, cladding and packing cases.
Anobium regularly attacks softwood (and some hardwoods) in any form. It was mostly thought to be a northern hemisphere problem – in Britain, Europe and North America, Anobium’s known as ‘woodworm’, because the larvae of the beetles, which live in the wood for anything up to 3 or 4 years, feed on the cellulose. Woodworm is considered to be the main cause of damage to timber in Britain, where houses are regularly fumigated to negate the risk of attack.
In New Zealand, all softwood framing is treated against possible Anobium attack. In Australia, Keith’s warnings have not been borne out so far. The threat for now and in the foreseeable future seems negligible, but the timber industry must consider that a major infestation could occur at any time – particularly as the supply of softwood framing from Europe increases. For the most part, Australia has been well protected by its isolation, but that doesn’t mean as the demand for framing increases and we import more softwood to meet that demand that the risk won’t also increase too.
As far as the builder is concerned, simply complying with the various codes of the day and meeting the statutory requirements probably isn’t enough to prevent a major structural insect infestation from causing extensive damage to a building. Most state-based systems are focused on day-to-day consumer protection covering defects and warranty issues over the course of a 6 – 7 year period (depending on the state).
Common law however, looks at issues of neglect and fitness for purpose – and it has no prescribed duration. There have been many cases where a builder has been deficient in his ‘duty of care’ and, 10 or 20 years down the track, has been brought to account.
A good lawyer, at some time in the future, could argue that the inclusion of a slightly elevated, above ground, static barrier system that is easily damaged, broken or bypassed, is hardly adequate ‘duty of care’ – particularly because at the time of construction unsusceptible materials were readily available (i.e. treated timber, steel etc.).
To my mind, not only does the builder need to consider what he or she puts out into the built environment, but the timber industry needs to become more proactive in its evaluation of the future expectations of the consumer, in this increasingly litigious world.
From the timber industry’s perspective, it’s not all doom and gloom, and I’m happy to say that one major Australian softwood producer is taking a leadership role in the fight against insect attack in structural timber framing.
Jackie Porter-Kay is the NSW Regional Manager for Hyne Timber, one of Australia’s largest softwood framing producers with mills in Queensland and Southern New South Wales. In a recent conversation with Jackie, she confirmed that starting on 1 September, all MGP softwood framing sold into the NSW market will only be available as a minimum, H2 Blue treated. NSW and the ACT markets are already very advanced in the supply of treated framing, and Hyne Timber are taking the lead to convert the balance of their market share over to T2 Blue.
This is an enormous step to take. Some may say it’s a gamble, but I believe it’s a bold initiative that others in the industry will soon follow.
Jackie indicated to me that Hyne believes this is the best course of action for the future of the Australian building industry – a very laudable position and one where they most certainly can claim the high ground. I put it to Jackie that it could easily be argued that Hyne was looking to shore up its bottom line by rationalising the manufacturing process, eliminating the need for duplicate stock holding and minimising their packaging and materials handling costs.
Jackie admitted that they are certainly very cognisant of being able to rationalise the issues associated with duplicate stock holding, and that is one of the key points they are using to explain the benefits to timber merchants and truss and frame manufacturers.
Jackie also advised me that some of their customers – particularly truss and frame manufacturers – are already moving towards treated framing only. This is because many of the larger volume house builders have already identified the long term ramifications that unchecked insect attack on completed projects could have on the future of their businesses – and they’re demanding treated framing.
From an industry position, if others follow suit the overall cost of production will rise as all framing stock goes through the treatment process – the unit cost of treatment will reduce though, as a consequence of increased volume – that’s another factor which may influence a move within the overall industry. This could result in higher profit for producers (and I’m sure they need it) or slight reductions in the selling price of treated timber; competition and supply and demand will sort that out.
I think that builders and specifiers also need to be proactive. The more you increase the demand for appropriately treated timber (or other unsusceptible framing material), the more accessible both in availability and price it will become; 100% usage will see termite and other insect attack on the framing of future housing stock eradicated – a good thing for the home owner, and a good thing for the builder’s peace of mind.
Ted Riddle has 47 years’ experience in the timber industry as a merchant, importer, producer and marketer.