Australian Termites – Cause and Effect
There are approximately 350 species of subterranean termites in Australia. Of these, approximately 20 or so species are of economic importance (cause financial loss through damage to timber in service). However, those relatively small number of species really do have a way of making their presence felt.
Figures provided by Archicentre (circa 2006) assessed the post-construction termite management problem as costing Australian home owners $910,000,000 per annum in treatment and repairs.
More recently than that though, Archicentre estimated that 650,000 Australian homes have become infested by termites over the last five years. The cost of treatment and repair of the resultant damage caused by these termite infestations has been estimated at $3.9 billion.
Treatment costs vary widely but usually sit between $1500 and $6,500. Repair costs for damage from termites are
not uncommonly in excess of $20,000.
Termite Management can be broadly divided into:
Pre Construction: A Pre-Construction Termite Management is a system or product which is integrated into a building or structure, during the construction phase.
Post Construction: The eradication and ongoing management of active termites within an existing building, structure or property.
Why Builders are key stakeholders in Pre-Construction Termite Management
It’s incumbent (a legal requirement) upon builders to ensure a termite management system that complies with the relevant legislation and
building codes is integrated into buildings during construction.
Purpose of a Termite Management System for New Construction
The purpose of a Pre-Construction Termite Management System is a system or treatment (stand alone or in combination) that deters, impedes or redirects termites away from gaining concealed entry into a building or structure. This results in the termites potentially betraying their presence and being detected and subsequently treated.
How long should it last?
A compliant Termite Management System intended for new construction must be designed to perform effectively for the acceptable service life of the building, being 50 years, unless it is easily and readily accessible for replenishment or replacement and is capable of being replenished or replaced.
What is suitable?
Local councils are usually the final arbitrators in deciding whether or not a particular system incorporated into a new structure is suitable and compliant as they sign off on it and issue the appropriate ‘Habitation Certificate’
The Australian Legislation behind Termite Management in New Construction
National Construction Code (NCC)
The NCC provides minimum requirements for safety, health, amenity and sustainability of design and construction of new buildings in Australia.
The NCC comprises the Building Code of Australia (BCA), Volume One and Two and the Plumbing Code of Australia (PCA), Volume Three (the Plumbing Code of Australia is given legal effect through the Plumbing and Drainage Act 2002 (QLD).
All three volumes are performance based codes meaning that a design solution can meet either the relevant Performance Requirement directly (Performance Solution) or a “Deemed to Satisfy” solution, which in some cases requires compliance with Australian Standards.
The NCC is given legal effect by relevant legislation in each State and Territory and contains provision for compliance and enforcement. This legislation prescribes or “calls up” the NCC to fulfil any technical requirements that must be satisfied when undertaking building work or plumbing and drainage installations. Therefore, compliance with the NCC is directly administered by the relevant State or Territory and not by the ABCB.
Building Code of Australia: (BCA)
The Building Code of Australia (BCA) is a uniform set of technical provisions for the design and construction of buildings and other structures throughout Australia (see previous section). The BCA is produced and maintained by the Australian Building Codes Board (ABCB), and given legal effect through the Building Act 1975.
The BCA is reviewed and amended each year to include various technical and regulatory changes. It is important for builders and other trades to keep up with the primary changes to ensure their building work complies with the code, which may avoid contractual disputes and potential litigation.
Australian Building Codes Board (ABCB)
A joint initiative of the Australian Government and state and territory governments, the ABCB addresses safety, health, amenity and sustainability issues through the National Construction Code (NCC). The intention of the ABCB is to achieve nationally consistent, minimum standards.
Part 3.1.3 ‘TERMITE RISK MANAGEMENT’ of The Australian Building Code Volume 2 deals with Appropriate Performance Requirements of Termite Management Systems and;
Associated Acceptable Construction Practice Compliance
The intent of these requirements is to provide specifications for varying termite management systems that deter termites from gaining entry to a building via a concealed route. It should be remembered however, that the installation of a termite management system will not stop or prevent termite activity from occurring on the site.
When a Pre=Construction Termite Management System fails
When a pre-con termite management system fails, provided the system or treatment complies with the relevant performance criteria, the cause can be due to one or more of the following:
1. Poor installation/application by the Termite Management System installer
2. Disturbance or damage by other trades or third parties
3. Property owners (unwittingly or ignorantly) which render the system ineffective or partially ineffective
1. Correct installation is crucial
The integrity of a system is often compromised from the outset, prior to the commencement of the system’s service life because sections or components of the system are integrated into the structure, making reliable visual inspection difficult. Consequently, a system may be ‘breached’ without any externally visible sign of termite activity.
So, the skills, knowledge and experience of the installer is crucial in achieving the desired outcomes. This author used to do a bit of ‘trouble-shooting’ and consulting for a major manufacturer of physical termite management systems. When their product ‘failed’ on a site, it was due to incorrect or ineffective installation, just about without exception.
Some states (eg. QLD) require dedicated training and licensing in addition to ‘general’ pest operator licensing for termite management professionals and termite management system installers. Builders and owner builders really need to ensure that their chosen termite management installers have undergone the appropriate training, are licensed and qualified (both with the relevant government licencing body and proprietary product manufacturers) and are experienced as Termite Management in New Construction presents continual challenges due to the wide array of systems and products and the kaleidoscope of building designs and construction sites.
2. Disturbance or damage by other trades
Many products and systems integrated into buildings are sometimes rendered ineffective from disturbance, damage or bridging over by the works or actions of other on-site trades who have little interest in and knowledge of termite management systems. This often goes unnoticed but may eventually be revealed when termites bridge over, breach through or simply by-pass a termite management system which has been rendered partially ineffective by someone other than the system installer.
3. Or at a later stage, actions done by property owners or third parties (unwittingly or intentionally) which render the system ineffective or partially ineffective
Examples of this are creating gardens, pouring concrete and/or installing pavers or landscaping up against new home and building foundations, creating finished ground levels above the level of the physical termite shielding or chemical impregnated sheeting and obscurement of the foundation slab edge which is meant to be an “inspection zone. This permits bridging of the system and/or concealed entry by termites into the building structure.
Requirements regarding many aspects of termite management in new construction does differ between state/territory and local government (councils), in response to varying termite pressure, termite species, conducive climatic conditions, geography and input from third parties The Australian Environmental Pest Managers Association (AEPMA)
As the professional pest management industry’s peak national body, the Australian Environmental Pest Management Association (AEPMA) is committed to promoting a culture of professionalism and innovation, not only in pest management but also in allied and associated industries such as building and construction.
AEPMA has developed and released several Industry Codes of Best Practice. Two of these codes specifically deal with termite management in Australia and are approved by the Australian Competition & Consumer Commission (follow the links above).
Types of Pre-Construction Termite Management Systems PHYSICAL Termite Management Systems (PTMS) wrongly termed “barriers”
This methodology is designed to prevent termites having access/ingress either onto or into the structure without dying or being chemically affected in that attempt.
Physical termite management systems (inclusive of the concrete slab) are simply finite termite shielding materials/products that are required to maintain their structural integrity so as to redirect termite movement to the perimeter of the building or out into the open where it hopefully becomes visible and then subsequently picked up during inspections. It is logically desirable that this occurs prior to termites gaining access to the building structure and timber. In other words, what some call “termite barriers” should really only be considered to be “termite channelling or monitoring systems”.
A PTMS is defined as a physical impediment to termite movement that is integrated into, or part of, the construction of a building. A PTMS may be constructed from a range of materials including stainless steel mesh, aluminium sheeting and even patented adhesives that may, or may not, include chemical additives, impregnation or enhancements but in the main, PTMS’s are pesticide free, hence the term ‘physical’ as opposed to ‘chemical’. The purpose of these systems is to deny access to termites below the point where the system is sandwiched into or applied to the building fabric.
However, It is possible for termites to bridge, or build over termite barriers/monitoring systems. Everything has limitations.
The termite technician, as part of the system/product inspection, checks the external perimeter, including the 75 mm inspection zone. This is actually the exposed (hopefully) edge of the concrete which is typical with ‘slab-on- ground’ construction and should be left visible and unobscured (requirement of the Australian Building Codes). In many instances however, the inspection zone is partly or in some cases, completely concealed by obstructions such as built up gardens, foliage, concrete and/or paver pathways and other such nuances that generally obstruct a comprehensive visual inspection. As mentioned earlier in this article, these obstructions are often ‘added on’ after construction has been completed by other trades at the behest of the new property owners.
Because most PTMS are, in part, encased in the mortar joint, it is virtually impossible to check as to whether or not the PTMS has retained its integrity so the inspection process does not ascertain any details in relation to the possible breakdown of the PTMS. The concrete slab and other componentry such as parge, penetration collars, etc. (i.e. The various items that combine to form the physical shielding required to redirect termite movement to the perimeter inspection zone where it can be observed and chemically treated) are often not able to be inspected properly.
The humble Ant Cap was the first Physical Termite Management component
All PTMS’s operate according to the principles of the ant cap which in reality, was the very first PTMS in operation. The ant cap is not designed to stop the progression of termite movement. Instead, it is simply designed to re- direct the termite movement into the open (termites forced to build around it) where it might be detected more readily during regular inspections. All PTMS’s are designed primarily as termite ‘re-directional’ or monitoring systems and would therefore, by definition, require regular inspections.
When subterranean termites go under, over and/or around ant caps to attack bearers, joists, floorboards and other timber components of a structure, it means that in effect, the ant cap has fulfilled its function. The ant cap has exposed the termite movement as the termites attempt to bypass it.
Another type of Physical Termite Management System for new construction are patented products in the form of granules or pebbles, which are synthetic or manufactured from a naturally mineral. With these products, there is a specific size specification range that the pebbles/stones must conform to, whereby each one is too heavy and large for termites to shift but at the same time, small enough so the termites cannot travel in between the individual pebbles/stones.
From memory, the first of this type was in the United States and/or Hawaii and was manufactured from Basalt, which is in plentiful supply there. Granite is much more abundant in Australia and therefore, is the mineral of choice for graded stone termite management products.
Graded stone termite products for new construction are installed around foundation slab penetrations and in wall cavities.
Adhesives and Parges
There are also several adhesive or bonding polymer sealant type products available that termites have great difficulty in penetrating. Some of these are applied by spraying on, others are painted on, some double as moisture barriers and some have a chemical/termiticide incorporated into the formulation. This system of new construction termite management is gaining popularity due to the flexibility of installation and application. These formulations can be installed or applied just about anywhere which is considered a potential termite entry point.
CHEMICAL Termite Management Systems Hand Spraying of Termicides
Hand spraying of termiticides (chemicals) was common place in Australia for a few decades but over the ensuing years from around 2000, hand spraying of soil substrates prior to the pouring of concrete slab foundations has declined. Many shire councils will now only accept hand spraying under additions and existing structures but not under complete, new buildings. The logic being that chemicals break down with time under concrete, which then leaves no ongoing protection for previously treated buildings against termites.
As a result, more longer term solutions such as reticulation systems (which can be replenished with chemicals) or chemically impregnated sheeting with extended service lives of up to 50 years are mandated by local government. Hand spraying is still acceptable in many council regions for additions to existing buildings.
Chemical Termite Management Systems (CTMS)
The purpose of a CTMS is to kill, repel or chemically affect termites that attempt to gain access into a structure. The means by which the chemical acts is determined by the active constituent therein and the mode of action of that chemical/agent. Post construction (existing buildings) termite control often involves chemical treatment of soil.
The objective is to either create a chemically treated zone to the soil or ground substrate, or install chemically treated materials to the exterior walls of a building, underneath a building and to all soil or ground in contact with any part of the foundation or sub-structure of a building. The chemical must be delivered to these specific locations within and around the building/structure. This is achieved by one of the following design concepts:
Chemically Impregnated Sheeting or Reticulation Systems
Where pre-construction is concerned, a CTMS can be designed as a chemically impregnated polyurethane sheeting membrane (termite “blanket or sheet”) These systems are intended to deny termite access or ingress to a structure via the action of a chemical on foraging termites when the termites come into contact with the treated sheeting membrane.
Chemically Impregnated Sheeting
Impregnated sheeting products in the main, consist of two plastic or polyethylene sheets with a chemically impregnated membrane sandwiched or encased in the middle. Synthetic pyrethroids are the favoured termiticide/insecticide group classification used in these sheeting products (Bifenthrin and Deltamethrin). These molecules are generally gentle on the environment and safe for the end users (property owners). The active ingredients are firmly ’fixed’ to the membrane, which minimises any safety risks to the installers.
The majority of sheeting products are registered for installation under the foundation slab, in wall cavities and around service penetrations which breach the concrete foundation slab such as drains.
Reticulated Termite Management Systems
This system/method involves the use of a reticulated system or network of piping used to deliver and distribute an active chemical formulation to soil (Reticulated Chemical Termite Management System or ‘Retic’), whereby the chemical termiticide is introduced into the soil medium under and around structures via hoses, tubes or flat tape (such as irrigation tape with emitters). These systems have been utilised extensively throughout Australia over the last 20 years. One of the key features of this system design is that the chemicals can be replenished at regular intervals, thus re-invigorating the treated zone(s).
Chemicals registered for use in reticulation systems (Australia)
In Australia, due to environmental and health concerns, the persistent, high vapour cyclodiene termiticides (organochlorines) were phased out in June of 1995, with the exception of northern Australia which was given a two year extension to permit research and innovation of an alternative chemical or product capable of managing/eliminating the voracious ‘Giant Termite’ (Mastotermes darwiniensis).
An organophosphate based liquid termiticide was then produced and heralded as the miracle replacement for the OC’s. However, It didn’t take too long before it was evident that Chlorpyrifos fell way short of expectations. Hence the introduction of new safer, less persistent but effective chemistries/molecules for termite management which are designed to break down gradually and not build up and compound in the eco-systems.
Termite Management in New Construction is quite a complex and diverse aspect of construction which often presents challenges to stakeholders (particularly builders). It is in the interest of all parties concerned to not only become aware of the legal requirements, statutory obligations and implications for non-compliance, but to also be familiar with the various termite management systems both in function and application.
About this author
Gary Stephenson Pest Industry Consultants
Training / Auditing / Consultancy / Compliance
Sydney, Australia. +61 0403 113 117
Certified & Qualified Lead Auditor – Quality Management Systems
AEPMA Field Biologist & Member of The Institute of Field Biologists
Accredited HACCP / Food Safety Auditor
Certified & Qualified Workplace Trainer & Assessor
Diploma of Business Management
Licensed Pest Management Technician
Certified, Qualified & Accredited Timber Pest/Termite Inspector & Technician
AEPMA Industry Codes of Best Practice Accredited Signatory
National Director AEPMA
AEPMA – NSW Council Delegate
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