Weathertightness is the term used to describe the resistance of a building to the weather. It’s not necessarily waterproofing, but ensuring against dampness and damage to buildings due to moisture.
Since the mid-1990s, a number of houses have been built using methods that will not withstand the weather conditions and therefore do not comply with the New Zealand Building Code. When it rains, some of these houses are leaking because of problems involving design and installation of materials, and in some cases, the materials were used inappropriately.
If there is no drainage or ventilation between the cladding and the framework, water becomes trapped and the potential for fungal growth and rotting increases.