Venting a Skillion Roof
A Skillion roof on a house is a shallow pitched roof usually pitched between 1 – 10 degrees and is usually quite low offering the minimal permissible height of approx 2.4 metres.
This area was often the leanto extension at the rear of a house that once was the outdoor laundry and converted to an enclosed area.
Today dwellings are built with this type of roof considered to be a cost effective approach.
The venting of residential skillion roof areas, with ceiling heights of less than 2.7m and roof pitch less than 10 degrees, is never entirely successful as the space between the roof and ceiling lining is non existent much the same as a raked or cathedral ceiling.
Areas with this type of roof requiring venting during summer can only be achieved by venting direct to atmosphere.
This approach requires a roof ventilator on the roof with an closable type of ceiling vent, or register, installed on the underside of the roof ventilator so as to control air movement passing through it. Much like a window that can be left open in inclement wet weather if necessary.
The ceiling/purge vent selection needs to be a highly efficient design that allows a high flow when required. This will not some questionable plastic product out of a hardware store that works poorly to begin with and not at all when dust gets into the mechanism and breaks as a consequence. Then you end up with a dust trap that continually reminds you of the flawed thought process that resulted in your choice.
Air ingress (entry) to this area is critical as the flow necessary could often be high.
Quality of air is also essential with air ingress via door and windows favouring the southern and eastern side of the building.
If you’re going to go the trouble of spending time and money, do it properly instead of on the cheap, because it will come back and bite you……..at the worst possible time.