Many older buildings have subfloor areas and these are required to be fully inspected. The subfloor area is a very important part of the inspection as it can reveal hidden underlying defects that can have a major adverse impact on a building.
Poorly ventilated and damp subfloor areas provide ideal conditions for timber pests such as wood decay, termites (Subterranean and Drywood species) and wood borers. Damp conditions can also adversely affect the structural integrity of steelwork causing corrosion and masonry components causing erosion.
Adequate ventilation is essential and it is quite common for older buildings to have little or no subfloor ventilation. Most modern homes are concrete slab on ground construction and do not have void areas that need ventilation.
Determining the general condition of pipes within the subfloor area is important, as any leaks would promote timber pests and building degradation.
Masonry or timber stumps should be checked for damp and decay. A steel rod is used to spear under the base of the timber stumps as the stump may look sound but wood decay or termites can extensively damage the stump below ground level requiring it to be replaced.
The under side of the floorboards are checked for timber pest damage, fungus or decay. Pine floorboards are checked for anobiid borer damage.