The purpose of roof space ventilation in new zealand s climatic environment is primarily moisture management keeping moisture sensitive building elements dry to maintain performance and durability.
Skillion roof ventilation nz.
The roofing industry is currently seeing a significant increase in complaints of leaking and condensation especially in systems like skillion roofs and curved roofs.
Vent s passive ventilation systems for skillion roofs have been designed to create continuous calculated unimpeded airflow that can exit the roof cavity.
Bu630 roof space ventilation.
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It is likely that even of an air change per hour would be adequate for an attic space but each ventilation design must take into account the type of roof the design of the building and the site environment.
In skillion roofs the roof cladding and ceiling run parallel typically within 300 mm of each other.
Mammoth skillion sections are designed to promoted high thermal performance in modern skillion roof designs.
A skillion pitched roof of any degree pitch requires continuous airflow of 25 000mm per lin m at eaves level unimpeded airflow through the roof cavity and ventilation at the ridge.
The roof space is generally inaccessible with little natural ventilation and the small roof space can accelerate problems with moisture.
Air pressures on a monopitch skillion roof a with and b without eaves.
Recent branz research provides advice on the best place for effective vent openings in low wind zones.
Roof space ventilation provides air exchange in the spaces above the ceiling insulation and below the roof cladding.
Some roof designs such as skillion roofs must include ventilation to manage roof moisture.
The high density sections are made from 100 polyester with a controlled loft to ensure the required 25mm air ventilation gap to the roof is always maintained.
Share in skillion roofs the space between purlins and insulation is usually limited to 25mm meaning airflow below the roofing underlay is extremely restricted.
The pitch of the roof is important as flat roofs cannot take advantage of the stack chimney effect that a roof slope can provide.
Whilst it is possible to retrofit passive ventilation solutions to existing buildings it is highly recommended to incorporate passive ventilation during the design phase of any new building project.
Passive roof ventilation products that provided continuous calculated unimpeded airflow that mitigates of internal moisture issues in roof cavities.
