Planning and Building Practices Increase Termite Risk
The move by governments to increase housing densities and the failure of many builders to clean up their site is increasing the risk of termite attacks in Australia according to Archicentre, the building advisory service of the Royal Australian Institute of Architects.
“Termite attack risk can also be increased with the clearing of land in urban areas for major infrastructure projects such as freeways,” said General Manager of Archicentre David Hallett.
“Termites had become an increasing risk management consideration for home buyers who are having both structural and pest reports carried out on proposed housing purchases.”
Mr Hallett said that there are an estimated 130,000 termite attacks per annum with a repair bill of $910 million and costing an average of $7,000 each to rectify.
“At Archicentre we are finding people ordering pre-purchase inspections are adding termite inspections onto their requests, especially with the increase in property prices.
“Termites do not discriminate between expensive and less valuable homes.”
“Higher density planning strategies mean more disturbances of termite nests, the forcing of termites to seek out alternative food sources and a greater difficulty of protecting properties from attack,” Mr Hallett said.
“When some home owners are confronted with the realisation that their home is infested by termites and that the eradication and damage cost could be expensive, they decide instead to sell their homes.”
Archicentre conducts thousands of pre-purchase housing inspections for consumers and in response to home buyers' requests has added a Pest Inspection Service with a $10,000 consumer guarantee to its services to ensure costly termite and pest problems are investigated.
In some cases Archicentre has found homeowners take steps to conceal the problem which for the unwary home buyer can mean an expensive lesson especially when access to areas is denied or patch up jobs cover up the problems.
Some of the problems Archicentre has encountered during home inspections include:
- A mattress placed on the floor and heavy boxes strategically placed to conceal damage.
- Access hatch to the ceiling nailed shut to prevent access. The roof framing was badly affected and was sagging.
- Skirtings and architraves patched and painted to conceal damage.
- A bedroom was locked during inspection times apparently “because it contained valuables.” In fact the floor had been totally destroyed.
EXTERNAL FACTORS INFLUENCING TERMITE ATTACK
A number of regional factors were identified that were likely to be associated with an increase in termite activity. These factors were common to Sydney, Melbourne and Brisbane.
Heavily treed areas
Trees, particularly eucalypts and other native species provide the natural nesting sites for most species of economically destructive termites. There was a high risk of termite attack in areas which had extensive native tree cover.
Middle aged housing estates
Housing estates that were thirty years of age or older had a higher than average incidence of termite activity and a subsequently increased risk of attack to homes. In many cases, these estates had been built on cleared tree areas where naturally occurring termite nests had been disrupted and the termites' food sources depleted. While it would appear that a significant number of years are required for mature colonies to re-establish themselves and cause widespread attack, there were cases of individual attacks on new homes and even on homes under construction. There was also evidence that the construction of new freeways in older areas increases the risk of termite attack to nearby homes by disrupting established foraging networks.
Old housing areas
One of the common factors influencing termite attack was poor sub floor clearance in older homes. This prevents good air circulation resulting in damp soil and sub floor conditions. Generally in homes of this type the floor construction was very low to the ground, providing termites with easy access to the floor structure. Older terrace houses were particularly susceptible to attack for these reasons.
Many home owners had inadvertently created conditions which invited a termite attack on their home. Unprotected timber in contact with the ground used in retaining walls, garden structures etcetera was found to be a common nesting area for subterranean termites. And landscaping practices such as mulching up against external walls allowed subterranean termites undetected access into the home, even when a termite treatment zone had been put in place.
Many termite infestations are initially caused by timber debris being left under the house, often as part of the original construction. A common problem area is where builders have filled the void area underneath a concrete porch or verandah with timber offcuts and other surplus material. These provide a potential new termite colony with protection, moisture and a rich source of food, the ingredients necessary for a future thriving nest.