Water leaks through wall claddings are often not seen from the outside, as has been found in the case of many leaky buildings.

Common locations where leaks occur include:

  • around doors and windows
  • at the base of walls (in particular where the outside ground level has been raised)
  • at junctions between materials
  • where decks and balconies are attached to the building
  • when top surfaces of balcony walls and parapets are inadequately flashed
  • where water has become trapped
  • where the cladding and wall have suffered impact damage
  • at board ends of horizontal weatherboards due to paint failure.

In addition to the annual checks described in the introduction (and depending on the type of house construction), you should also:

  • ensure that wall cavity ventilation holes remain clear – these holes play an important role in allowing rainwater that gets behind the cladding to drain away or dry out. Clear vent holes out where they are blocked
  • check visible sealant joints and face seal coatings. These are typically found in claddings installed from the 1990s onward and play a crucial role in weathertightness. Clean and repair, recoat or replace them as necessary
  • check flashings, such as the head flashings above windows, to ensure that water is being directed to the outside and not getting behind the cladding.

Some homes built in the 1990s/early 2000s had wall claddings, construction methods and design elements that did not prove to be weathertight. In some cases the type of cladding chosen was inappropriate for the environment. There are cases where the leaks and subsequent damage did not become visible until years after the construction was complete.

If you think your home is leaky and you want expert guidance, contact an NZIBS building surveyor. You can also find out more about leaky buildings in our maintenance guide on weathertightness, and also on our dedicated website www.weathertight.org.nz.

Many weathertightness failures would have been avoidable, or would have been less serious and less expensive, if regular inspections and maintenance had been carried out.