Floor Void Ventilation Requirements

Voids should be ventilated by openings providing not less than 1500mm 2 per metre run of external wall or 500mm 2 per m 2 of floor area whichever gives the greater opening area.

Floor void ventilation requirements.

This requires a minimum of 3 500 mm2of net open area for every 1 m2of the house plan floor area. A minimum ventilation void of 150mm should be provided below the underside of precast concrete and timber suspended floors. Elevated buildings in a zones in an elevated building located in an a zone any flood zone beginning with the letter a the lowest floor used for rating is the lowest elevated floor with the. The timloc vent units will achieve.

The new zealand building code clause e2 external moisture includes an acceptable solution e2 as1 for subfloor ventilation of suspended timber floors. Another common way these vents can be blocked is by an extension with a solid floor being built onto a property without providing proper access to the original vents. Additionally if the span is greater than 10m the overall ventilation area should be increased to at least 0 6 of the total roof area. Where the exterior ground level is too high to carry air to the sub floor void in a straight line a telescopic underfloor vent should be attached to the back of the air brick to conduct and protect the airflow across up to 5 brick courses.

The building regulations approved document c states suspended timber floors and suspended concrete floors including block and beam have a provision for ventilation on two opposing external walls of not less than 1500mm per metre run of external wall or 500mm per metre of floor area whichever works out to give the greater amount of ventilation. Telescopic gas vent outlets 1201 1201ab 1206 gvl900 the combined units will allow ventilation outlets to either a sub floor void or via a range of adaptors to a venting layer and allow the provision of a minimum of one complete volume change per 24 hours as required by the nhbc. And the floor level of the garage is below the level of the building use the garage floor as the lowest floor for rating. Supports underneath the floor are permanent and.

A suspended floor is a ground floor with a void underneath the structure. Duo pitch roofs greater than 200 pitch or greater than 10m span should have additional ventilation at the ridge to assist airflow through the roof void equivalent to at least a 3 mm wide continuous gap. However the floor structure is supported by external and internal walls. Ventilation openings should be provided on at least two opposite sides.

High volume change potential 150mm 300mm total void.