Roof Ventilation Regulations

R806 2 minimum vent area.

Roof ventilation regulations.

The key to proper ventilation of your roof and attic is balance. 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. Cold roofs must have ventilation. These ventilation needs are calculated differently.

The air gap dimensions shown on the drawings are the minimum widths required for clear continuous ventilation air paths at the eaves. Condensation encourages rot and mould growth. Warm roofs must have a vcl bonded to the deck. The amount of space you devote to intake must be equal to the amount you allow for exhaust and these must be calculated according to the size of your attic and slope of your roof.

Required ventilation openings shall open directly to the outside air and shall be protected to prevent the entry of birds rodents snakes and other similar creatures. Part h of the building regulations regarding drainage state that water should drain to one or two edges. Roof voids must be ventilated in order to stop warm air condensing on cold surfaces. Roofs must be wind resistant and strong enough to walk on.

Waterproofing should extend up the adjacent walls at least 150mm from the roof surface. Openings in roof framing members shall conform to the requirements of section r802 7.