Under Floor Ventilation Requirements

Finned pre stamped foundation sidewall or soffit vent.

Under floor ventilation requirements.

The purpose of sub floor ventilation is to replace the moist air with fresh dryer air. Finned louvers deflect rain or snow and prevent large insects from entering. Reveal for stucco or siding. This standard is called termite management and it sets out a range of good building practices for avoiding termite attack and maintaining adequate subfloor ventilation.

The total area of ventilation openings is permitted to be reduced to 1 1 500 of the under floor area where the ground surface is covered with a class i vapor retarder material and. Here is an example. You will need to chisel out a much larger area than a single brick to be able to pass the angled duct through. Ensure ventilation has a free and unobstructed path to all areas by making provision for ventilation air to pass through sleeper walls and other sub floor obstructions.

Pre stamped foundation sidewall or soffit vent. The following are exceptions to sections 1203 3 and 1203 3 1. A house has 1 500 square feet of crawl space area. Australian standard 3660 specifies the minimum clearance requirements between the ground and the underside of a subfloor.

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. Ventilation 2010 edition incorporating 2010 and 2013 amendments ref. Houses built during the 1970s were sometimes built with a floor structure that extended past the foundation line so ventilation could be provided over the top of the foundation wall and between the floor joists. Isbn 978 1 85946 679 7 pdf 683kb this file may not be suitable for users of assistive technology.

Pre punched nailing guides provided on flange. The timloc airbrick telescopic underfloor vent and extension piece accessories are ideal robust and convenient solutions for providing natural ventilation into underfloor voids. If necessary install mesh over this gap to stop vermin from getting under the house. The simplest method used to achieve this is to install a number of vents in the wall around the building and rely on natural ventilation air movement to take care of the underfloor ventilation.

Adequate ventilation reduces unwanted heat and moisture reduces utility bills. Where warranted by climatic conditions ventilation openings to the outdoors are not required if ventilation openings to the interior are provided. To convert to square inches multiply by 144. View the sub floor ventilation requirements here.

Ventilate the underfloor space by providing ventilation in two opposing external walls. The minimum net area of ventilation opening must not be less than 1 square foot for each 150 square feet of under floor space area.