Internal Moisture
Recent research shows that internal moisture & condensation in the roof space is a widespread and growing problem across New Zealand.
Weather tightness requirements have been specified for many decades without the required ventilation. The lack of passive ventilation causes condensation to occur. From this, mould is easily formed which is a major contributor to the alarmingly high level of asthma and respiratory diseases experienced in New Zealand. Passive ventilation is a method of allowing continuous airflow into a building above the thermal envelope. This eliminates internal moisture from the roof cavity and prevents condensation and mould from forming.
Roof Ventilation
There are many product options which will provide passive ventilation for new build and existing homes. As this is a relatively new concept to New Zealand, we have recommended the following range of product options as a simple and effective guideline.
The products have been selected to achieve the recommended airflow for roof pitches above 15° (10,000mm2 lin/m) and below 15° (25,000 mm2 lin/m).
If You Heat and Insulate and you don’t Ventilate, you will Condensate!
VENT is New Zealand’s leading specialist in the supply of passive ventilation systems and products. 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. The pre-occupation with making homes increasingly more weather tight over the last few decades has prevented our buildings from breathing and has led to houses being designed and built without passive ventilation. Design and build of this nature gives rise to the potential for internal moisture issues.
VENT systems are specifically tailored for New Zealand buildings and the extreme climatic conditions. VENT products are tried, tested and designed to avoid compromising the thermal envelopes of our buildings.
