Building Construction, Renovation, Maintenance & Advice

Methods for Avoiding or Eradicating Termites

Last issue we looked at termites and the fact that, apart from earthquakes, these tiny beasties probably present the greatest single threat our buildings will have to face.

MacArthur? Huh, he had it easy fighting the yellow peril compared to the task of ridding yourself of nibblius tinyus. These little beasties come by the billion, you can't negotiate with them, they don't get scared and, just like the Blues Brothers, they're on a mission, not from God but in the world of termites the next best thing - "Termitus Regina".

We need effective strategies to protect ourselves from their voracious appetites. Let us look at the ways we can protect ourselves.

Building Design for Prevention of Termites

The most effective strategy is to plan termite resisting strategies at the building design stage and set protection systems in place during construction.

Build on a single complete reinforced concrete slab at least 150mm thick, set the slab above ground level with its edges exposed all around. Termites will not be able to get through such a slab and to enter the building will have to build mud tunnels over the exposed edge of the slab where they can be easily detected.

Anywhere the slab is breached such as where pipes or electrical conduits pass through is a point of weakness where termites can enter. Termites can pass through concrete construction joints, under tiles and between bricks or batako blocks without you seeing them.

Do not build anything such as boundary walls, gates or sheds that bypass the edge of the slab.

Use steel for roof structures and tiles not wood for floors and you will avoid the biggest concerns regarding termite damage.

Termite Resistent Wood

Use termite resisting timber, care is needed however, generally only the heartwood is termite resistant. In addition different termites have different menu choices.

Here in Indonesia four termite resistant timbers are of particular interest, these are:
• Dalbergia latifolia (Indian Rosewood known as sonokeling or sonobrits in Indonesia),
• Eusideroxylon zwageri (Borneo Ironwood known as Ulin or Belian in Indonesia)
• Intsia bijuga (Merbau also known as Ipil or kwila)
• Tectona grandis (Common Teak known as Jati in Indonesia)

Species of Indonesian timbers that are considered very susceptible to termite attack are:
• Agathis alba (known as amboina, Borneo Kauri or East Indonesian Kauri)
• Dipterocarpus species (known as Keruing, Apitong or Gurjan)
• Mangifera species (Includes Mango)

Galvanised Steel Termite Barriers (Ant caps and strips)

A widely used traditional method in Australia was to build houses on the top of wooden posts or "stumps". Each stump has an ant cap, a circular disk of thin galvanised steel to stop termites getting into the house above through the inside of the wood and so without detection. This approach has been developed over the years and many wooden items such as wooden verandah posts and gates are mounted on steel bases concreted into the ground.

Stainless Steel Mesh (Termimesh)

A mechanical barrier system is available in Australia and has become very popular replacing toxic chemical barrier systems. The system consists of a very fine stainless steel mesh which is installed around edges and over the joints of the concrete slabs that form the structure and floor of a building. It is also installed around any pipes or cables that come through the floor slab.

This system is very effective, lasts the lifetime of the building and is particularly suitable where buildings are built on single reinforced concrete floor slabs. In Bali the success of this system depends on the concrete being cast correctly and highly skilled installation. It can be applied after construction but this can be difficult.

Fine Grit Barrier Systems Granite Guard

A very environmentally safe system uses a bed of fine crushed rock under and around the building. The rock particles have to be just the correct size being small enough to prevent termites getting through between the grains but large enough that the termites cannot move them. The system is simple, relatively low cost, environmentally responsible and lasts the life of the building.

Wood Treatment

Drywood termites are difficult to deal with and one of the few methods is to use wood treatments. All wood is sprayed or soaked in termiticide with particular importance on the ends of the wood where termites tend to get in. It is best carried out before construction starts.

Once a house is built the wood is often coated with varnish or paint and it is not possible to reach the ends of the wood in the joints. As a result termites can travel extensively through a building eating their way through the centre of wooden sections without ever coming to the surface. Insecticide sprayed on the surface may be ineffective and you may not know you have termites until the wood falls apart.

Unfortunately builders in Bali rarely treat wood against termites before construction.

Soil Treatment and Chemical Barriers

The most common anti termite methods used by pest control companies in Bali are chemical barrier treatments which involve saturating the soil around the foundations and under floors with copious amounts of insecticide to form a protective barrier around your property.

There are two types of chemicals used. Until recently virtually all chemical treatments were "repellent" barriers which repel or kill the termites. The repellent is unpleasant and poisonous to the termite and drives it away. Unfortunately any gaps in the barrier and the termites will find their way through. Repellent barriers do not tend to kill the colony and depend on a complete unbroken barrier being set up.

Non Repellent Chemical Barriers

In recent years a more sophisticated type of termiticide has been developed for use in chemical barriers. These are "non repellent" chemicals that are undetectable by termites, they cannot smell or taste them. They pick them up and take them back to the colony where, as a result of their feeding and grooming habits the termiticide is passed on throughout the colony eventually destroying it (so the theory goes).

Ground treatment with chemical barriers is best carried out before a building is built. Unfortunately all too often In Bali expensive anti termite treatment is rarely carried out by cost conscious builders before construction and so is very often carried out after buildings have been completed. This means that to create an effective barrier holes have to be drilled through floors in all the rooms of the house a maximum of 40 cms apart and 40 cms out from walls.

Problems with Barrier Systems

Sadly I have seen a number of beautiful floors damaged using this method. You will find most pest control companies will not offer other methods.

You should also note that the chemicals in barrier systems tend to break down in the soil and so treatments only last 3 to 5 years before retreatment is required.

The holes can, in fact, create a further problem providing more ways for termites to get into the building once the chemicals have become ineffective.

As I said before in Bali this method is widely used in spite of the risk of ground water contamination and the very common practice of pumping household water from wells and bores.

In other parts of the world where people are far more concerned about personal safety other protective methods are being used.

Baiting Systems

Baits are particularly useful where chemical soil barriers are not appropriate or if you don't want chemicals in the ground or holes drilled all over that nice floor. Untreated cellulose matter is placed in small boxes around the perimeter or under the floor of the property. If termites are around they will start to feed on the baits alerting you of their presence. Once termites are feeding a small amount of termiticide is added to the bait. The termites take this back to the colony where, over time, it will poison the whole colony.
This method has several advantages but it may be difficult to get the termites to the bait particularly if they are under a floor slab behind foundation walls.

Baits do not kill ants.

Fumigation

Fumigation is particularly suitable for dry wood termites which don't come down to the ground. It is a major exercise involving the erection of a tent over the whole building which is then filled with toxic gas.

Boric (or boracic) Acid

Boric acid is a natural white powder which is particularly effective against cockroaches, ants and termites. It can be mixed with water and painted onto affected areas. Boric acid presents less of a threat to human health than more commonly used modern insecticides but is also less efficacious.

Freezing

Termites keep their nests at very warm temperatures and in some countries the nest is found through heat seeking methods and the queen is killed by freezing using liquid nitrogen, an effective and non polluting method. Not easy to carry out though.

Natural Plant Extracts

Some plants have developed their own defences against termites by secreting anti termite oils and resins which make it difficult to digest cellulose. Research has been carried out over the years and a commercial product has now been developed in Australia which is a "paint on" termite barrier made from a range of non toxic plant extracts. The barrier chemicals strongly repel termites and prevent them feeding.

Ants

Ants are the natural enemies of termites and can help you to keep them away. When ants and termites encounter each other they are hostile and the ants are usually stronger and tend to win.

Eat Them

In many cultures people consider flying termites a delicacy to be enjoyed on those rare occasions when the termites swarm. Do yourself a favour and eat them. Pull their wings off, a dash of tabasco, yum yum.

Copyright © Phil Wilson 2009
This article or any part of it cannot be copied or reproduced without permission from the copyright owner.

5 September 2017 Copyright © Mr Fixit,
Jl Bypass Ngurah Rai, Gg Penyu No 1, Sanur, Bali 80228, Indonesia
Telephone: +62-361-288-789, Fax:+62-361-284-180