The first in a two-part series by Dr Don Ewart examining the effect of the revised National Construction Code on termite-proofing work.
With the end of the National Construction Code 2016 grace period approaching, which still permits works to Australian Standard 3660.1 – 2000 (Termite management for new building work), Dr Don Ewart reviews how the changes impact on termite work. In this issue, the first part of this article focuses on understanding the codes themselves and compliance issues. The second part for the article in the next issue will explore how the systems can be fitted together to create an integrated termite management system.
Subterranean termite work for new buildings is meant to; 1) stop the building falling down, or 2) keep termites out.
Termite work is generally done to the building because the builder needs it to get the house approved.
Understanding the Codes and Standards
The Australian Building Codes Board (ABCB) are happy with termites getting into a building and even feeding on furniture and some trims, just so long as structural damage doesn’t threaten the building’s ability to perform. That is, the construction must continue to withstand the loads that might be applied to the structure. Building frames with steel, cypress pine or treated pine is OK by them, as set out in the Building Code of Australia (BCA), which is Volumes 1 & 2 of the National Construction Code (NCC). You can download all these documents, and more, for free at abcb.gov.au
Australian Standards take a different approach and AS 3660.1–2014 sets out ways to install a system aimed at keeping termites out of the building. This is often called the ‘whole-of-house’ approach and it relies on blocking paths that termites might take to get in without being seen. Collars on pipes in concrete slabs are a prime example of a path- blocker, but plastic sheets, poisoned soil and even finely crushed rock are also used (Figure 1).
If the hidden paths are blocked, and termites do come up the outside walls, their “bridging” tubes can be easily seen, and the attack controlled. To make any such termite workings easily seen and to deter termites, the Standard sets up inspection zones over which the termites would need to explore and then build. The ideal inspection zone is one that goes from ground level to a bit above your head. In Queensland, some of the old style high-set houses have lasted better than 100 years with this approach.
Australian Standards always specify only the necessary minimum required for the job, and every provision in a building Standard has to justify the cost and balance against the likely acceptable risk. The minimum inspection zone in AS 3660.1 is set at 75mm, roughly the height of a standard house brick1. A one brick hurdle will not absolutely deter all termite attacks but, it is usually sufficient, cheap and is more than enough so that any shelter tube built as a bridge over it, can be readily seen (Figure 2).
While the BCA is fine with termite management works being viewed as ‘set and forget’, the Standard requires regular inspections. This is where the industry idea of annual inspections comes from.
Using the BCA and Standards
The BCA uses (calls up) the Standard as a recipe book of ways (acceptable solutions) to manage termite risk. Really, AS 3660.1 has no greater purpose than to meet the needs of the ABCB and be called up into the BCA. Way back in the pre-BCA days of the early 90s, AS 3660 was a user-friendly document with much useful advice. Today, the latest version of AS 3660.1 must be read alongside the BCA, as some requirements are given in the BCA but not explained in the Standard. For example, the Standard does not include a requirement to supply a treatment sticker (durable notice), as that’s already in the BCA, and doubling up, however helpful, isn’t allowed.2
The ABCB sees AS 3660.1 as a guide so that builders can buy what they need from the hardware store and install it themselves, just as they do for most other referenced Standards. The pest management industry has different ideas and sees termite management as an ongoing process that requires specific training and expertise to get right.
Whatever happened to barriers?
‘Barrier’ is an easy concept, but it doesn’t suit all systems. If you use a non-repellent termiticide such as Termidor, Premise, Altriset and similar, it is possible for the termites to pass through a zone of treated soil before being killed. This creates problems for people who want the terms used to be absolute. So under pressure, the ABCB required the Standard to use other words instead. The termite Standards now talk about ‘termite management systems’ and ‘termite management system components’. People will still use the term ‘barrier’, just as they do ‘Part A’ and ‘Part B’ sprays that were cut 20 years ago, but the important thing is to stop using the word ‘barrier’ in documentation immediately.
Meeting your requirements
One big change in AS 3660.1-2014 that industry seems to have forgotten, is that reticulation needs to be provided to reapply chemical where there is not access for reapplication. This holds for ‘concealed and inaccessible areas’ (Clause 7.1.1) so any areas under floors and around a building where the soil is not exposed to be sprayed. Drilling or cutting concrete and the lifting of pavers is an invasive procedure.
It is important that installers check to see what will happen to the building perimeter after the chemical is applied and to install perimeter reticulation wherever the soil will be covered. For under slab chemical application to soil, the use of reticulation would then normally be mandatory.
NCC 2016 creates problems
The 2016 Building Code carries a cut-off date of 30 April 2017, after which builders cannot use the old AS 3660.1-2000 to achieve BCA compliance. It is important that pest managers doing pre-construction work get and read AS 3660.1-2014 before this date so that work practices and documentation are appropriately updated. Unless you are a developer of termite management systems, there is absolutely no need to purchase the testing Standard AS 3660.3-2014. It is informative, but is not needed for regular work.
Unfortunately, in their zeal, the ABCB also included the testing Standard AS 3660.3-2000 in that cut-off, which effectively means that any product you use in buildings under construction after that date has to have been assessed to AS 3660.3-2014. This has created a huge mess as there has not been enough time since NCC 2016 came out, for manufacturers to complete new tests that meet the more stringent requirements of AS 3660.3-2014.
The ABCB also now require chemicals used for new construction after 30 April 2017 to be tested to AS 3660.3-2014 and not just APVMA approved. This may be a problem for some generic products. This is believed to be because the ABCB need evidence-based testing.
All an installer needs to meet this new BCA testing requirement, is certification from the product manufacturer that their product has been assessed in compliance with AS 3660.3-2014. Ensystex were first to provide such a letter. In the longer run, manufacturers should add this compliance claim to product labels.
More ways to skin a cat
The Standard is just one way to reach BCA compliance, resistant framing is another option3 (Figure 3). A third way is through the ABCB certification scheme known as CodeMark. Most of the big systems have a CodeMark covering compliance with the Standard, but a few have some non- complying installation details. If you are using these details, or a system that isn’t in compliance with Standards, then be sure to leave out any mention of the Standards in your paperwork. Don’t claim what you haven’t done.
The most obvious example is Dow’s new AlwaysActive bait, which has a CodeMark allowing baits to be used for new construction. Baits don’t provide an inspection zone and baits for new construction are ruled out in the testing Standard, AS 3660.3-2014. If your builder has given you a works specification requiring compliance with AS 3660,4 then you must either install a complying system or have the builder’s specification changed.
A fourth way to meet the BCA is to have a suitably qualified expert sign off on a proposed solution to the effect that it meets the requirements. This is fraught with danger for the installer as a building inspector can reject the installed solution. Compliance with AS 3660.1-2014 or a CodeMark certificate is much less likely to result in problems.
In part two of this article we’ll look at problems with builders’ poly, the various systems approaches and how these can be fitted together to make an ‘integrated termite management system’.
Dr Don Ewart
1 Many fired-clay house bricks are only 73mm.
2 Oddly, the BCA only requires a durable termite system notice where the system is installed as in AS 3660.1, but not where resistant framing is used. That includes framing with some naturally resistant timbers that termites occasionally eat!
3 Queenslanders be careful. In the Queensland version of the BCA, door jambs, architraves and skirting boards are considered to be structural, not trim.
4 Careful here, as the specification may be to outdated Standards.
Dr Don Ewart, a doctor of termites, Chairs the Standards Australia Committee. He is a consultant to industry and pest managers, teaches pest management for Melbourne Polytechnic and can be found at Dr Don’s Termite Pages.