We suggest what to look for to avoid buying a leaky home.

Houses that may present weathertightness problems

Houses identified as being at high risk of leaking are those using monolithic cladding systems, sometimes known as ‘Mediterranean’ style. They usually feature textured wall surfaces made out of plaster over polystyrene or fibre cement sheet. They sometimes haveWall claddings in contact with the ground.

• Wall claddings in contact with the ground.
• Recessed windows.
• Roofs with narrow or no eaves.
• More than one storey.
• Design features such as solid balustrades, complex roof design and envelope shapes where roofs frequently intersect with walls on upper floors. :

  "Complicated" house

• Decks and balconies that jut out from walls.
• Enclosed or concealed gutters.
• Inadequate sub-floor ventilation for timber floors.

These features may not allow adequately for deflection or drainage of water unless particular care is taken in the design and construction.

"Mediterranean style" house

Many were built with untreated, kiln-dried framing timber which is susceptible to rot if it gets wet and cannot dry out.

Inspecting homes with potential weathertightness problems

If you are interested in a home that has these types of features, an independent building survey is essential. Ask your building surveyor to look particularly for signs of water damage or potential leaks. They should use a moisture meter. Moisture meters are generally non-invasive meters that can indicate moisture problems and water leaks without making holes in the walls. They do not guarantee that no weathertight problems exist, but might find areas of high moisture levels. (Check that your inspector is using a non-invasive meter.)

However, not all defects can be found, so ask the person doing the inspection to highlight the areas they couldn’t check and identify risk areas that might warrant further investigation. Most pre-purchase inspection reports will have a disclaimer on weathertightness as some of it is too difficult to check without removing linings or claddings. But a pre-purchase inspection is still recommended.

Have a close look at the property yourself. Check for the following:

• Rust or other unusual staining on exterior walls.
• Any cracks in the cladding where rainwater could enter.
• Wall claddings should be clear of the ground and of balconies and decks to stop water soaking upwards.
• There should be sheetmetal or plastic flashings over windows and doors.
• Any dampness and rot around windows and doors.
• Decks should be set below internal floor levels.
• Parapet walls should have flashings covering their top surface.
• Any penetrations, such as pipes or wires, should be correctly flashed where they enter the roof or cladding.
• Any broken sealant.

  Claddings must be clear of the deck surface

• Inside – any stains on ceilings, spongy flooring, mould spots on interior walls, and particularly, musty smells.
• Top fixed handrails on balustrades.

Ask the vendor specifically if there have been any leaks or weathertightness related problems, and whether a claim has been lodged with the Weathertight Homes Resolution Service.

If you buy a home to later find it has problems with weathertightness, you may have remedies under the law.

For more information see our Leaky buildings resource.