What a timber pest inspection checks, part by part
A pre-purchase timber pest inspection is meant to comment on evidence of present or past activity and any damage with it, and on signs of earlier treatments.
It should also assess how susceptible the building is to attack, name the conditions that could raise that risk, and recommend further investigation or action where it is needed.
LOOK visual. TAP non-marking sounding. MOISTURE content of materials. QBCC’s words for the standard.
The house, enlarged
Roof space roof timbers inside the timber: not inspected Rooms skirting boards, architraves, cornices, the wet rooms inside the walls: not inspected Subfloor piers or stumps and ant caps, the slab edge on a slab floor, termites are more likely to go undetectedThe band, 0 to 30 m
0 m, against the wall Garden beds and mulch built up against the wall. Materials stacked against the wall. 30 m, the band’s edge (QBCC) The surrounding property within 30 metres of the building, in QBCC’s account of the standard. Near the building, no stated distance Paving that sends water towards the house. Trees or bush near the building.What the report comments on
The methods are narrow. The standard’s pre-purchase inspection is visual, as Queensland’s building regulator (the QBCC) describes it, with non-marking sounding of elements and an assessment of the moisture content of materials.
The ground it covers, in the QBCC’s description: within the house, and across the surrounding property to 30 metres from the building.
| What the report comments on |
|---|
| Present or past activity |
| Damage with it |
| Signs of earlier treatments |
| Susceptibility |
| Conditions that raise the risk |
| Further investigation or action |
Activity: the places to look
Queensland’s guidance says where to check for termite mud galleries or damage: foundations, piers or stumps and the sub-floor area, skirting boards, architraves, cornices and mouldings, and roof timbers, especially softwood.
The CSIRO’s guide to managing termites says most attacks come from the soil, and points to shelter tubes over stumps and ant caps, and along the edges of concrete slabs.
The same guide notes frass, gritty like sand or ground pepper, beneath small holes in wood, and reads that as drywood termites at work.
Damage: what the surface can show
Queensland’s guidance says galleries are a common indicator of an infestation, and that damage in timber may show as mud plastering along joints and cracks.
None of that is the whole story of the damage, because the inspection reads surfaces. Victoria’s building regulator describes termites working concealed, often undetected, destroying timber from the inside and leaving a thin outer layer in place.
Past treatments and the barrier
The QBCC’s booklet is precise about what caps do. They do not prevent termites getting in; they block concealed entry and encourage the termites into the open, where an inspection can notice them.
Queensland’s advice is that regular inspections, at least every 12 months or more often in high risk areas, show whether termites have bridged the barrier.
An exposed slab edge works in the same direction, as the same booklet puts it: it will not stop termites gaining access, but it will encourage them out into the open, where they can be noticed and identified.
Susceptibility, and the conditions that raise it
The fourth item, susceptibility, is where the building’s construction enters the report. Queensland’s guidance says an infestation is more likely to remain undetected in a building with a slab-on-ground floor than in one with a suspended floor.
The Victorian Building Authority gives its tips for avoiding termite damage directly: garden beds and mulch should not be built up against walls, and materials should not be stacked against them either.
The CSIRO’s guide singles out bathrooms and laundries, along with areas that drain poorly, such as paving that directs water towards the house.
Queensland’s booklet adds that in areas near trees or bush, inspections may need to be more frequent than once a year.
Recommendations, and the line the report draws
The last item on the list sends a reader somewhere: recommendations for further investigation or action, where the inspection found reason for them.
An inspection is limited by anything that cannot be inspected for any reason, by the weather, and by the quality of what the owner says about the place.
The next guide is What it cannot see.
Queensland’s building regulator (the QBCC): QBCC’s termite management systems guide describes the standard’s inspection this way, for Queensland readers.