Ventilation Sub Floor Ventilation Sub-floor ventilation is probably the most significant factort contributing to the success of a suspended timber floor. The minimum unobstructed area of ventilation is 7300mm squared per metre of external wall. A typical example is one 225 mm x 150mm metal vent fixed at every fourth purpend (or every fifty bricks). Solid brick houses, especially terrace houses with party walls are inherently under ventilated. Insuffucent air circularting under a house may contribute to a damp sub-floor environment. A damp sub-floor environment may eventually lead to the destructlon of the sub-floor structural timbers. This lack of air uncler may be attributed to two factors: Lack of sub-floor space and the presence of barriers under the house. The ground levels are too high to allow air to circulate. In addition, the presence of solid brick foundations may be preventing the through passage of air under the house. Under floor heating ducts and other sub-floor fittings further constrict air flows. The sub-floor vents are ineffective. Sub - Floor Vents don't work effectively when: The vents have been placed too high to vent under floor. The vents have been placed opposite the main sub-floor bearers or other support timbers which effectively block the passage of air. The build up of the surrounding ground, paving etc have impinged on the vents. The vents stop at the inner brick course and vent to cavity only. The existing vents are blocked by debris. Remedial works undertaken by F.G. James to increase air circulation in the subfloor areas of properties include: Installation of additional sub-floor vents Sub-floor ground excavation & flooring repair Penetration of foundation walls & dwarf walls Installation of fully ducted sub-floor fan systems Suspension of existing heating ducts Removal of oversites Replacement of obsolete vents with modern vents For further information on Ventilation please call (03) 9885 9444 or send an email to enquiries@fgjames.com.au