Concealed Internal Wall Areas (Termite Risk)
Internal wall cavities, top plates in the roof space, and sub-floor framing cannot be visually inspected during a standard building inspection. AS 4349.3 requires inspectors to report whenever access limitations prevent verification of timber condition - these concealed zones are where termite activity most commonly goes undetected until structural damage is advanced.
Severity rationale
The modal score is 3, accounting for 79.0% of the 1,677 observations (1,324 cases). A further 272 observations (16.2%) sit at score 4, pushing the average to 3.11. The severity reflects inspection limitation rather than confirmed damage - most findings are precautionary. Scores reach 4 when the concealed area is in a known high-termite-risk zone, where the inability to inspect removes the last line of early-detection defence. Only one observation recorded a score of 1, indicating this defect is almost never treated as trivial in practice.
Causes
- Standard plasterboard linings conceal all internal wall framing from visual inspection
- Wall insulation, ducting, or services blocking access to roof-space top plates
- Low sub-floor clearance or stored items preventing inspection of bearers and joists
- No access hatch or borescope entry point available in the wall cavity
- Prior or ongoing termite activity hidden by existing linings - unconfirmed without invasive inspection
Symptoms to look for
- Inspector notes that one or more internal wall areas could not be visually assessed
- No access hatch in roof space or sub-floor to reach top plates or perimeter framing
- Ducting, insulation batts, or stored items obstruct sightlines to structural timbers
- Inability to confirm absence of termite entry or mud leads within wall cavities
- Report flags the inspection as limited in scope due to access constraints
Remedies
- Commission an invasive inspection - borescope through wall cavities or targeted removal of a small section of cladding at high-risk areas (e.g., wet walls, walls near garden beds)
- Install a permanent access hatch in the roof space over the perimeter top plates for future inspections
- Engage a licensed pest inspector to conduct a thermal imaging or microwave radar scan as a non-invasive supplementary method
- Schedule an annual termite inspection under AS 3660.2 so concealed areas are monitored consistently over time
Where we see this most
These suburbs show the highest concentration of concealed internal wall areas (termite risk) in our inspection data (minimum five observations). Click a suburb to see its full defect profile.
Worth asking our inspector about this specifically.
Where this appears on a pre-purchase report alongside other termite conducive conditions, a targeted invasive inspection before settlement is worth considering. In the absence of other risk factors, scheduling a borescope inspection within 12 months is a reasonable response.