termitebarrier.com.au · Sheet 05
Sheet 05Upkeep
Keeping a termite barrier working
A termite barrier depends on nothing bridging or breaching it and on someone competent inspecting it regularly: the code’s explanatory note says that, besides correct installation, a system’s effectiveness relies on regular maintenance and competent inspection. In Queensland, the building commission’s booklet sets out what owners should and should not do, and that list is reproduced in full below.
General information, not building advice. The list below is Queensland’s, from QBCC. Wherever you are, read your own durable notice for the installer’s or manufacturer’s inspection recommendations.
What the code leaves to the owner
The code does not set a maintenance schedule itself. It puts one on the wall: the durable notice must say what the installer or manufacturer recommends about how often, and how thoroughly, the building is inspected for termites, and it must tell the people in the building that the system should be inspected and maintained. (Sheet 02 reads the notice line by line.)
The code also treats things fixed to a house as part of the problem. Its Table 3.4.2 gives attachments such as decks, carports, steps and heated water systems two options: a termite management system of their own, or an inspection zone between the attachment and the building.
QBCC’s list for owners, reproduced whole
Word for word from the “Reduce the risks” section of QBCC’s booklet, which QBCC publishes under a CC BY 4.0 licence. The booklet prints it in two columns; it is set out here as QBCC’s advice to owners, then the practices it warns against. Nothing is left out.
To deter concealed termite entry to the dwelling, regular maintenance is essential.
The following list is a guide to what owners should and should not do to protect their home from termites.
- Have the building inspected at least annually by a suitably qualified termite management contractor, licensed in Queensland by QBCC. A free licence history check can be performed at qbcc.qld.gov.au. More frequent inspections may be required in high risk areas (such as areas near trees or bush).
- Owners should perform their own ongoing inspections between professional inspections.
- Owners should be careful not to compromise their termite management system. Termite infestations can occur when a perimeter system has been made ineffective.
- Special care should be taken to protect the ‘weep holes’ (vertical joints between bricks close to ground level that are left open to allow any moisture to escape outside the house). 75mm minimum clearance is recommended from the bottom of any weep hole to the top of the garden bed, concrete or unit paving.
- Freestanding structures should be built with a minimum 25mm inspection zone between the structure and the house.
The most frequent cause of termite infestation is where a perimeter system has been bridged or breached, thus rendering it ineffective.
Some common practices that may increase the risk of termite problems include:
- Placing turf, paving, concrete paths, bark and garden beds up against the house wall (you may need to re-establish the termite system).
NOTE: Concrete paths or driveways placed against a building may require a chemical reticulation system to be installed in the ground before concreting.
- Leaving loose timber stacked up or leaning against the house.
- Installing new services involving underground connections to the house (such as pay TV)
- Installing new water tanks against the dwelling spanning over the width of the termite management.
- Constructing a pergola (75mm minimum clearance is recommended between the finished ground or pavement level and the bottom of the timber posts)
- Attaching fences, carports, or garages to the home. You should ensure the soil surrounding members in contact with the ground is treated.
The list’s three clearances, in section
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A · Weep hole to garden bedQBCC’s list recommends at least 75 mm from the bottom of any weep hole to the top of the garden bed, concrete or unit paving.
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B · Freestanding structure to houseThe list asks for a minimum 25 mm inspection zone between a freestanding structure and the house.
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C · Pergola post to pavingFor a pergola, the list recommends at least 75 mm between the finished ground or pavement level and the bottom of the timber posts.
Diagrams, not to scale. The metal stirrup under the post in drawing C follows CSIRO’s guide, which suggests stopping termites reaching the house from outdoor timber posts by cutting them short of the soil and standing them on metal stirrups.
What other official guides add
- Keep weep holes from ending up below soil level, and keep a path beside the house slab at least 75 mm lower than the termite barrier, typically a standard brick course. (QBCC, Queensland)
- When a new concrete slab is laid against an older one, seal or protect the gap between them with a suitable termite management system. (CSIRO)
- Finish external siding and cement sheet at least 100 mm above the soil, so they cannot hide a way in, and keep soil and mulch below the slab and clear of weep holes. (CSIRO)
- Before renovating, think about what the work will do to the termite management system. (QBCC, Queensland)
After a flood
In Queensland, QBCC tells homeowners whose internal floors were surrounded or covered by floodwater to check for signs of damage to their termite management system. The flood guide it hosts says a licensed pest controller should inspect and assess the system and reinstate it to the building code, AS 3660.1 and the manufacturer’s recommendations.
Most of these items come down to keeping the edge of the house in plain view. QBCC’s booklet explains why that matters: an exposed slab edge will not stop termites getting in, but it encourages them out into the open, where they can be noticed and identified.