Some weathertightness failures could have been avoided if effective maintenance had been carried out.

Most wall claddings, for example, require regular maintenance to ensure that the building remains weathertight. Cleaning and repainting/recoating as required are essential. Some roof claddings also require recoating from time to time.

Exterior maintenance includes: 

  • ensuring that wall cavity ventilation holes remain clear
  • checking face seal coatings, cleaning and recoating as necessary. (Many cladding materials that incorporate face seal coatings are fundamentally reliant upon these for weathertight performance, and if they are not maintained, the cladding material will absorb water and fail.)
  • checking critical sealant joints – many cladding systems incorporate exposed sealant joints that are fundamental in stopping water penetrating critical junctions
  • checking critical flashings, such as window head flashings, to ensure that water is deflected over a critical penetration in the cladding
  • cleaning and recoating wall finishes
  • clearing roof gutters, including internal gutters
  • inspecting roof flashings/membranes/claddings.

Some houses are at greater risk of weathertightness failure, such as those that are very complex, have monolithic face sealed exteriors, parapets, balustrades and minimal eaves protection or are built in very exposed locations. With these, homeowners carrying out maintenance should look for:

  • cracks, splits or open joints in the cladding 
  • sealant that has come loose 
  • metal corrosion 
  • raised flashings 
  • gaps at the ends of flashings 
  • rotten timber 
  • cupped or buckled weatherboards 
  • loose-fitting cover boards, scribers or plugs 
  • missing roof fixings or holes in the roof 
  • overflowing spouting 
  • surface efflorescence 
  • stained or dark patches on walls 
  • gaps in junctions between different materials or building features 
  • gaps around cantilevered deck joists or other cladding penetrations 
  • gaps around window seals or sashes 
  • joints or mitres that have opened up or where the paint has cracked 
  • water ponding on a roof or membrane deck surface. 

Where any of these are found, they should be addressed immediately.