A sub-floor is the structure and crawl space between the lowest floor and the ground. High moisture levels in these areas promote fungal decay and other timber pests such as termites.
All sub-floors and crawl spaces should be considered as having potential moisture and water problems. The most common causes for these problems are found on the outside of the house, usually from roof and surface water drainage.
Some houses look near perfect internally, but an inspection of this subfloor supported the reason and proved the benefit of engaging Jim’s Building Inspections to conduct a thorough building inspection.
The site and subfloor drainage in this area was found to be inadequate at the time of inspection, creating potential for subsequent water damage to associated building elements. Buildings built below the natural ground line, such as in sloping blocks, may be susceptible to water ingress into the subfloor area depending on preventative measures, such as waterproofing and adequate drainage, installed during or post construction.
It is important that water does not lie against the base of walls or within the subfloor. Surrounding paths and external ground levels should be sloped to drain water away from walls. Downpipes should not disgorge stormwater onto lower walls or plinths. Stormwater should be carried away by large, regularly cleaned drains. Ground levels may need to be lowered to expose a buried DPC.
Where site drainage is inadequate, installation of an Agricultural (Aggie) Drain may be required. A qualified plumber should be appointed to further inspect the property and perform any remedial works as necessary. Water damage and secondary defects are likely to occur if left unmanaged.