Sub-floor ventilation

If your building inspection has suggested that the sub-floor ventilation appears inadequate or sub-standard then it is important that you address this issue with a degree of urgency.

The space under the flooring of your home is an integral component of the buildings overall function, particularly where timber flooring is present. It is an area that is often considered unimportant by home owners and often used as a mere storage facility; however, the area under your home is vital.  

The sub-floor area has many functions

If your building inspection has suggested that the sub-floor ventilation appears inadequate or sub-standard then it is important that you address this issue with a degree of urgency.

The space under the flooring of your home is an integral component of the buildings overall function, particularly where timber flooring is present. It is an area that is often considered unimportant by home owners and often used as a mere storage facility; however, the area under your home is vital.

The sub-floor area has many functions.
Apart from obvious functions such as allowing the fitting and run of plumbing pipes, wastes and electrical wiring the sub-floor also allows the building to breath.

Where timber flooring is present, the space below the flooring must have adequate cross flow ventilation. If the void areas are too small, blocked or has insufficient perimeter ventilation grills then damage can occur as a result of condensation and humidity. Mold and fungi can develop that can be harmful to your health.

The soil beneath your building contain moisture and the air below the floor absorbs this moisture raising the humidity. Any timber work such as joists, bearers and flooring will also absorb this moisture often resulting in wood decay, mould and deformation to the framing members.

It is common for floor areas to convex upward as a result of increased moisture content where the joists separate from the bearers causing the floor to have bounce.

Installation of sub-floor vents

Perimeter vents and their positioning allow for cross flow ventilation from the front to back and from side to side. Cross flow ventilation decreases and nullifies the occurrence of humidity and condensation. As a general rule perimeter vents should start approximately 600mm in from the corner of the wall and be fitted at about every 1200mm therein. They are usually placed just below floor level.

There are a variety of different types of vents available depending on the age and type of building. The type of vent in most cases is not that important, however, they must be able to allow sufficient flow of air. It is important to ensure that the vents are not blocked, either externally by garden beds, excessive vegetation, or internally by the storage of items or other materials.

If your building inspection report has identified a blockage then you should treat this issue with a degree of urgency.

Termite or timber pest infestation

Poor ventilation and resulting moisture, condensation and humidity issues are highly conducive to timber pest infestation. Termites are drawn to areas that have high moisture content. Termites are a destructive pest and all avenues to ensure correct sub-floor ventilation should be taken.

If your building inspection report identifies poor ventilation then it would be prudent to have a licensed timber pest inspector carry out a termite inspection. Have the inspector assess the whole your property.

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