Sub-floor areas are poorly monitored. They are out of sight and in some cases not inspected by the homeowner, yet it is one of the important structural areas and can have an effect on human health and the building. The sub-floor needs to be fairly dry in minimising humidity. This leads to lower microbial growth, reduced termite infestation and less damage to sub-floor timber members. Timbers above 20% moisture content can be conducive to microbial growth.
Neglecting the sub-floor area can contribute to the musty smell in the living space especially in damp conditions. The high moisture laden air is drawn by infiltration from the sub-floor space and distributed into the living area, resulting in greater mould growth especially in cupboards and on clothing.
There are journal articles stating that houses on hillsides on bare ground with dirt can release 40 to 50 litres of water a day. This can be a recipe for high humidity and mould growth leading to damage of structural members.
Ventilation and Humidity:
Ventilation of the sub-floor is important and is well documented in the Building Code of Australia and Australian Standard 3660. Even though these standards are applicable to new building they can be used as guidelines for older buildings. Ventilation allows the movement of air in the sub floor space which assists in reducing stagnation of air and expelling some of the musty smell created in the sub-floor.
Ventilation is not the total answer to sub-floor problems. Ventilation including addressing soil moisture would reduce the effects of condensation, microbial growth and decay.
Our services include:
• site visit to measure humidity and air flow
• inspection of areas that have poor air movement
• advise on remedial actions