Hint 1 : Subterranean Termites

The most destructive pest we come across in the Sydney region is, of course, the subterranean termite. This voracious insect lives in colonies at the base of trees and stumps or underground, and sends out long underground tunnels from this nest in search of food. They often extend these underground galleries up into houses or other building structures where they feed on timber within, and then take this food back to the main colony.

To think of the termite nest as an underground beehive that eats wood, is a pretty good image of what is happening.

When trying to ascertain the termite risk it is necessary to understand a few simple principles:

  1. The first and most important of these is that the closer the building is to the ground, the higher the termite risk, so contrary to popular belief, concrete slab construction is more susceptible to termites than the traditional house on bearers and joists which is built off the ground.

  2. The higher the exterior level, whether it is soil, pavers, or garden beds, the greater the termite risk. Therefore if the exterior soil level is above the internal level, the termite risk is exceptionally high.

  3. The more steeply sloping the block, the greater the termite risk, as movement of soil often provides bridges into the structure.

  4. The more modifications a house has, the greater the termite risk.

  5. The more moisture there is in a house, the greater the termite risk.

Hint 2 : What Can I Do To Avoid Termites?

We are often asked what simple things home owners can do to reduce their termite risk. Where people go wrong is that they are simply unaware of what termite activity is occurring around the property, so the termites carry on undetected, causing thousands of dollars worth of damage.

  1. For this reason it is recommended to have regular inspections by one of our fully qualified, accredited technicians. A good inspection will advise not only whether or not termites are active, but also whether or not there are conditions conducive to termites.

  2. Reduce the amount of timber on the ground around the house. It amazes me how people want to avoid termite problems and yet they encourage termites to feed on timber placed around the house in the form of sleeper retaining walls etc.

  3. Ensure that all drainage and plumbing is free from leaks and that moisture problems are rectified.

  4. If the property is on a concrete slab, ensure the edge of the slab is exposed all the way around the house. Any areas where the slab is not exposed should be considered high risk areas.

  5. If the property is on bearers and joists, ensure the subfloor area is well ventilated and dry, and remove any timber that is in contact with the ground from the subfloor area. (The subfloor is the area beneath the floor).

  6. Ensure that the exterior level is well below the height of the dampcourse.

  7. Check additions to the house, such as pergolas, and make sure that there are metal stirrups between the wooden poles of the pergola and the ground. There is often soil build-up or paving that has been added since the pergola was built, creating a bridge between the ground and the timber thus allowing the termites access to the pergola.

Hint 3 : Renovating on a Concrete Slab & Termites

When a home is built on a raft concrete slab, it is particularly important to make sure that the edge of the concrete slab is visible all the way around.

The most common entry point for termites in this kind of structure is over the edge of the concrete slab, and people hide this entry point by building up gardens and landscaping too high. In some cases the gardens can be a metre or more above the height of the slab.

In these cases it is advisable to excavate and use retaining walls built out of non-termite susceptible material, to keep the level away from the wall and expose the edge of the slab.

Removing soil from the outer wall of the house will also prevent moisture building up in the cavity which can cause wet rot as well as encourage termites.

If the property has an infilled concrete slab, that is - the slab was poured inside the foundation walls, the outside level must be below the weepholes but preferably below the footing, as these are the two main entry points in this type of structure.

It is important with any concrete slab structure that all small additions abutting the outer wall are lower than the slab edge. Often things such as the hot water service, an air-conditioner, even a waste pipe leaving the wall, will provide the termites with an unseen entry point over the slab edge.

When controlling termites in slab houses, it is found in the vast majority of cases that the termites are gaining entry from the outer edge of the slab, not through the concrete slab, as often believed.

Hint 4 : Prior to, and During, Construction Pest Management

When looking at building a new home it certainly pays to involve a pest management consultant in the early stages. Often the wrong house design has been chosen for a particular site. That is - a house that is quite a low risk on one site, may be a high risk on another site.

All trees and stumps on the property, within a 50m radius of the building, should be investigated for termite colonies before any earth moving or tree removal. These colonies are often buried in fill beneath the structure and are difficult to locate and control in years to come. Remember that an individual termite colony can live for over three decades. Ensure that any trees moved are totally removed from the site and not buried there. It is advised that the entire root system be removed from the ground.

Ensure that a good termite barrier is installed during construction, prior to the laying of any concrete slabs or the laying of timber bearers and joist flooring.

This treatment alone does not give adequate protection against termite attack. After construction, termite barriers should be installed around the perimeter edge of the building, and it is important to ensure that no bridges are created over these barriers by the addition of anything abutting the outer foundation wall.

When building a house on bearers and joists, it is important that there is maximum air flow under the house. There should be a cross-flow ventilation from all four sides of the building. This helps prevent a build up of moisture under the house which encourages termites and wet rot, as well as other household pests such as cockroaches. Again, this is important to consider when designing the house. Too often this sort of thing is left until the dampness or the termites have arrived.

Hint 5 : I've Found Termites! What Do I Do?

If termites are discovered in or around the home, it is important to do the following things:

  1. Stop doing whatever it was that caused you to find the termites.

  2. If any termites have fallen outside their galleries or are visible, collect a few specimens and preserve them in spirits.

  3. Call on a Pestforce Consultant for professional advice and to arrange an appointment to assess the problems.

It is important not to attempt any treatment yourself. Do not disturb the termites any further, as they will often retreat from the house and make treatment more difficult. If any wall linings have been removed to discover the termites, it is best to cover the area again.

Specimens should be collected if termites are found outside the house, so that they can be identified. Correct identification is imperative in determining the risk and is also useful when looking for the nest.

When treating termites, our primary goal is to destroy the nest. This can be done indirectly from working within the house, but in many cases the opportunity to attempt this is lost because the termites have retreated due to disturbance.

Our second goal when treating termites is to close off all entry point into the structure. The building is then checked after this treatment.

Any ongoing activity is a sign that either there are more entry points not yet discovered, there is a nest within the building, or there is dampness.

It is most important that the termites are left completely alone so that the correct checks can be made. If they are gone before treatment, due to disturbance, nobody really knows.