Bearers and joists
The horizontal timber members supporting a raised timber floor. Bearers sit on stumps/piers; joists sit on bearers; floorboards sit on joists.
Bearers run perpendicular to joists. Bearers carry the joists; joists carry the floorboards or sheet flooring. Together they form the structural floor system.
Failure modes: termite damage (especially Coptotermes acinaciformis in Adelaide), fungal decay from sub-floor moisture, splitting from overloading, sagging from undersized members or excessive spans.
Inspectors crawl the sub-floor where accessible to inspect bearer and joist condition. Inaccessible sub-floor areas are explicitly noted as 'limitations' in the report.
Sub-floor ventilation
Air circulation under timber-framed floors. Inadequate ventilation causes timber decay, fungal growth, and termite-friendly conditions.
Coptotermes acinaciformis
The dominant subterranean termite species in metropolitan Adelaide. Highly destructive, builds large underground colonies.