There is no simple answer to in-house ventilation. As BRANZ Building Physicist, Stephen McNeil stated in a recent article: "sufficient ventilation is crucial as our homes become more airtight. A mix of passive and mechanical options can work well, but all designs should start by getting the source extraction measures right." It's about the whole system and how its design efficiently releases moisture from the building.
Facing the same issue with in-house ventilation, a builder by trade, David Easton is building his own home in Bombay. When David talked to Scott Harris, an experienced roofer, on how he can address this kind of issue, Scott recommended Metrotile's integrated vent solutions. The vents are integrated with the roof tiles and offer a replacement for traditional penetrations, without the reliance on flashings or silicone to remain weathertight for the life of the structure. "I'm happy to choose the integrated venting system," says David, "as a builder, I don't need to worry about the soffit for an air outlet, and there's no need for my plumber climbing up onto the roof to seal it."
There are two extraction vents (HV160) and two sanitary vents (HV110), which help to efficiently remove moisture from David's new home. He said ventilation must be watertight and the integrated design with Metrotile's interlocking roof tiles are the perfect solution.
The Extraction vent is designed to provide an integrated outlet for both passive and mechanically vented rooms. It is an ideal outlet for bathrooms, the kitchen and laundry extraction systems, but will work equally well as an outlet for any passively ducted areas where the release of moist air from the structure is desirable. It is far preferable to after-market mushroom type roof vents that require a penetration in the roof and additional flashings to retain the roof's weathertight integrity.
Metrotile also has a roof vent — LV75 Roof Space Vent which is designed to provide an integrated outlet for the passive release of moisture laden air from the roof space. When used in conjunction with venting at the eaves, it creates a simple in / out airflow pattern to adequately ventilate the roof space.
Roof: Metrotile Shake profile, Grey Friars colour
Builder: Phoenix Builders Ltd — David Easton 027 289 5176
Roofer: SH Roofing Ltd — Scott Harris 021 424 542
Read Stephen McNeil's full ventilation article