Some roof designs such as skillion roofs must include ventilation to manage roof moisture.
Skillion roof ventilation nz.
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.
Ventilating a home with no roof cavity a flat roof or a skillion roof design is something that should be planned prior to building and should involve a ventilation specialist and the architect who both understand each others point of view and the needs of the client.
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.
Achieving calculated continuous and unimpeded airflow through the roof cavity is relatively straight forward.
In high wind zones the placement of vents in metal and tile clad skillion roofs might not be critical.
Nzmrm and underlay manufacturers believe the answer lies in increasing what is currently the non existent ventilation of roof spaces.
We have approached dbh and branz to request an urgent investigation into this issue so far without result.
Roof and under deck spaces share the same construction materials and similar construction techniques as walls which have in the past failed from the ingress of moisture lack of drainage and ventilation to dissapate moisture that has entered the internals of the wall roof itself.
There are only two ways to remove moisture from any container ie your home.
Our systems are structured and specifically tailored for new zealand buildings and the extreme climatic conditions.
Especially in systems like skillion roofs and curved roofs.
The roof space is generally inaccessible with little natural ventilation and the small roof space can accelerate problems with moisture.
Skillion roofs need carefully designed and installed ventilation to reduce the risk of moisture related problems.
Recent branz research provides advice on the best place for effective vent openings in low wind zones.
In skillion roofs the roof cladding and ceiling run parallel typically within 300 mm of each other.
To mitigate the risk of internal moisture both branz and the metal roofing manufacturers association of new zealand highly recommend ventilating skillion roofs.
Vent was created as a direct result of the misconception that the leaky homes disaster that gripped new zealand was caused solely by external moisture penetration and product failure.
Mammoth skillion sections are designed to promoted high thermal performance in modern skillion roof designs.
