Building a home or renovating?
With up to a third of all houses in Australia having some history of termite attack, when building a new home or extension, it’s important to consider termite protection.
Having compliant termite protection is part of the sign off by the building inspector, so it’s important to get it right!
In most areas of Australia, the building needs to be designed and constructed to prevent the concealed entry of termites.
Successful termite protection for a building is achieved when the physical elements of the building work in conjunction with suitable chemical and physical termite protection products, to create a “termite barrier”.
The finished building and any termite protection measures need to block any concealed termite entry points, to meet Australia Standards AS 3660.1 – 2014: Termite Management, Part 1: New Building Work.
Call a termite professional before you build!
Getting a termite professional involved at the planning stage of the project will help you design a termite smart building and make sure you get the best protection for your budget and meet all necessary regulations. Often an experience termite professional will also suggest potential improvements to the building plans delivering a better overall result and saving you money.
A word of warning. Builders are not experts on termite protection and many builders will often recommend the cheapest termite protection to meet regulations, in order to make more profit. This is not necessarily the best option for the homeowner who often want to get the best protection to protect their home. Using a termite professional at the early stages ensures you can review all the options from an independent expert.
Termite protection for different construction types
The different construction types and building designs will have different points of weakness / potential termite entry points, which determines the areas that need termite protection.
There are various types of concrete slabs designs, but as long as they are built to standard, they should not crack. However, it is common to still have underslab treatments. Two types of underslab treatments are available; polymer sheeting and chemical treatments. With new building regulations, any chemical treatment under a concrete slab needs to have a system in place to replenish the chemical. This is achieved by installation of a reticulation system on the soil surface, before the slab is poured. The reticulation system is a series of interconnected tubes which can be pumped up with chemical which then leaks out of small holes in the tubes and seeps into the soil.
Even if there are no cracks in the slab, there are points of weakness where utility pipes pass through the slab. These entry points through the concrete slab are typically protected by hard or soft plastic termite collars, which are placed over the pipes before the concrete is poured, embedding them in the concrete.
Sometimes buildings are constructed using more than one concrete slab. Any joins in concrete slabs are an easy termite entry point and are typically protected by a flexible termite filler or sealant.
Where the concrete slab joins the perimeter wall is a particular point of weakness. This join and the wall cavity need to be protected. A range of sheeting materials and cavity fillers can be used to provide this protection.
The exposed edge of the concrete slab can be used as part of the termite management system on the exterior perimeter wall. If a minimum of 75 mm of the slab edge is visible above the soil level then no additional physical or chemical product is required around the perimeter. HOWEVER, this requires the homeowner to maintain this exposed edge and not cover it with garden beds, paths or other landscaping. If the concrete slab is covered by soil, there needs to be protection within the wall cavity and / or a chemical treatment to the soil around the perimeter of the home.
Homes built on brick or concrete piers, or even treated wood poles, are an older style of construction but still used today, more commonly on sloping sites or areas where flooding may occur.
The piers under the home need to have a barrier in place between the pier and the flooring timbers. Typically, metal termite capping is used and is designed to stop termites moving up inside the pier (yes they can move up the inside of brick piers), as it forces them to build their mud tubes around the “ant cap” to gain access to the flooring timbers. When this happens these mud tubes can be easily spotted and the problem dealt with.
As with concrete slab homes, the perimeter of the home also needs to be protected. Typically, metal or polymer sheeting is used to prevent termites moving up inside the perimeter sub-wall to access the wall cavity.
Double brick homes are so called because the walls are made of two layers of brick separated by a wall cavity. In contrast to a brick veneer home, which consists of a timber frame with a single layer of brick on the outside, the lack of timber in a double brick home often gives owners the impression they won’t suffer a termite attack. This is not the case!
If the building contains wood and there’s a way for termites to get in, any building can suffer a termite attack. A double brick home will often have a wood roofing timbers as a well as wooden floors, doors and windows frames, all of which can be attacked by termites.
Double brick homes require the same protection as brick veneer homes.
Metal framed homes are often marketed as termite proof. Certainly termites will not eat the metal framework. However, if there’s a way for termites to get into the house, termites will happily eat any wood elements in a metal frame home, such as flooring, doors, window frames and cupboards. There are plenty of examples of this occurring. Metal framed homes still need termite protection.
Building and termite protection regulations when building extensions, whether using a builder or doing it yourself, still apply!
In some respects, ensuring you have a continuous termite protection system for the whole building is more tricky when building an extension as there is the need to protect the join between the new extension and the existing building.
Internal renovations, especially to “wet areas” – kitchens, laundries and bathrooms – also need to meet termite protection (as well as waterproofing) regulations. These are areas in the home which are the most common termite entry points – they often have a source of water (leak) and a concealed entry point. DIY renovators need to be confident of their skills and have an understanding of the regulations to ensure they don’t build a future termite problem!
Types of termite protection
Termite professionals will use a range of products to protect the various structural elements that represent a potential termite entry point.
Collars are used on concrete slab homes to block any gaps that may appear around pipework that penetrates the concrete slab. There are hard collars (rigid) and soft collars (flexible), with the different collar types used in different situations. Some come with insecticide impregnated for extra protection, but this generally isn’t necessary.
These collars are wrapped around the utility pipes or conduits before the concrete slab is poured and positioned so the collar set in the middle of the concrete slab, blocking any potential gaps.
Solid metal sheeting on top of brick piers – the traditional “ant” capping – is still used today. However, whereas it also used to be used at the base of perimeter walls, this is less common nowadays.
More common for perimeter wall protection are metal mesh products. These are lighter and more flexible making them easy to install. The mesh size is such that the termites cannot pass through the mesh.
As an alternative to metal sheeting, a range of polymer (plastic) sheeting is available, impregnated with insecticide. The sheet presents a physical barrier and the insecticide acts as a repellent, killing any termites that come in direct contact.
Rolls of different sizes are available for installations under perimeter walls and on piers.
Polymer sheeting is often used under concrete slabs as a damp proofing membrane. Through the incorporation of insecticide, some sheeting products can also be used as both damp proofing and termite protection under concrete slabs.
Sometimes instead of blocking termite entry with a sheeting material, granular products placed inside the wall cavity are chosen. A variety of granule types are available; glass, stone and polymer beads (impregnated with insecticide).
The stone and glass fragment products work on the principle that the granule size is such that the termites cannot move the granules, and as long as a sufficiently deep layer is installed the termites cannot crawl between the gaps, thus preventing termite access. The polymer beads also have the benefit of the repellent insecticide.
Flexible fillers containing insecticide are important for filling all the awkward gaps such as joins in concrete slabs. They can also be useful in rectifying mistakes or areas where protection may have been missed.
There are a range of sealants, paints and foams. Some foam products are available in pre-formed rolls others form a foam in situ filling the void to be protected.
Traditionally insecticides could be sprayed on the soil before the slab was poured. However, new regulations specify that chemicals can only be used if they can be replenished in the future, ensuring continued protection. To do this reticulations systems (a series of hose-like pipes with small holes) needs to be installed before pouring the slab. The reticulation can then be pumped up with insecticide every few years, with the insecticide leaking out into the soil to maintain protection.
The use of chemical application around the perimeter of the building may also be an option and indeed it is a common way to protect existing buildings to prevent termite attack. However, if used as a protection measure during the construction process it will need to be combined with other measures and if paths or driveways are to be laid, a reticulation system will need to be included as well.
Physical termite protection products (even those impregnated with insecticide) are designed to last the lifetime of the building (nominally 50 years)… but check individual products.
Chemical treatments will last anywhere up to 10 years, depending on the product used and dose applied. Often for chemical applied through a reticulation system they will recommend an application of a lower dose more frequently, requiring the system to be re-charged every 3 years (for example).
Our library has a large number of articles on termite protection products and techniques for protecting new homes and renovations from termite attack – pre-construction termite protection.
Ongoing termite management
As with any termite protection, ongoing maintenance is vital. There are two key elements to ensure your termite management system continues to perform over time:
- Have regular termite inspections (at least annually)
- Follow an instructions about maintenance of your termite management system
Most physical elements of the management systems will continue to work for many years, but they aren’t quite “set and forget”. It’s important to remember the systems are in place and understand how they work, so that any gardening, landscaping or renovation activities that may be considered don’t bridge the termite protection measures, providing termites easy access to your home.
What is concealed termite entry?
With termites able to squeeze through gaps smaller than 2 mm, there are lots of potential routes into your home! Many such entry points are under the building or within the walls – these are called concealed entry points as you cannot see them. If termites access your house through a concealed entry point, they can do significant damage before their presence is detected.
Buildings are constructed and termite protection products are installed to eliminate all the concealed termite entry points. This does not mean termites cannot access your home, it just means that the only way for termites to get in are through visible routes (eg. On the outside of walls). Obviously once they become visible, they can be dealt with before significant damage is done. This is the reason regular termite inspections are a must.