Hingaia Peninsula School in Karaka, Auckland recently built a large new extension which features a combination of classrooms and shared spaces. To mitigate the risk of internal moisture, the Ministry of Education specified a VENT passive ventilation system for the extension's long run skillion roof.
James Johnston, Commercial Manager of VENT explains that the company has been involved in a number of school rebuilds, extensions and reclads over the past couple of years. In the case of Hingaia Peninsula School, he is proud to have supplied a complete passive ventilation system. “The beauty of this project was that it was a complete four product combination. It’s the perfect system to create passive ventilation through the skillion roof cavity.”
The installed system features a G2500 over fascia vent, a VB20 vented batten, RV10P ridge vent, and a G1275 eaves comb filler — a combination of products that work together to ensure calculated airflow of 2500mm square per linear metre of air passing through the roof cavity.
The vented battens on top of the purlins ensure airflow is unimpeded through the roof cavity, while the ridge vent allows natural convection of warm moist air to escape the cavity. Where there is wind movement, the ridge vent also creates negative pressure to draw airflow through the roof cavity. While not a ventilation component, the eaves comb filler contributes by preventing any ingress of birds nesting in the roof cavity while still allowing airflow below roof cladding and above roof underlay.
Installation was completed by Reel Roofing, who took to installing the VENT products with ease. “It was a perfect specification and application from start to finish,” says Johnston.
Johnston is particularly pleased with the use of the full system of products as it will protect the building and occupants for years to come. ”It will prevent structural decay of building products and prevent the build-up of harmful moulds that could start to grow and fester in the roof cavity due to moisture. As a result, it contributes to creating a healthy environment for the kids who will be in the building every day.”
VENT’s passive ventilation system is a worthwhile investment in the school building as it will minimise future maintenance and ensure the longevity of the school extension. “Designed right, applied correctly, we know this roof is going to stand the test of time,” says Johnston