Decks, balconies and balustrades of leaky homes

Last updated: 31 August 2016

Some decks, balconies and balustrades of leaky homes could be at risk of collapsing. If your house has a deck or balcony, this information sheet summarises information about the risks to decks and balconies of leaky homes.

Structures that may pose a risk are those that rely on timber beams for structural support. Those at greatest risk include balconies on buildings with lightweight claddings that imitate concrete or masonry, balconies and decks supported by untreated kiln-dried timber, and balconies on which water pools.

A balustrade is a barrier built around the edge of a balcony or deck. Those at greatest risk include enclosed balustrades covered with what appears to be solid cladding that imitates concrete or masonry. Water can leak inside the cladding where it gets trapped and rots the framing timber.

Often any potential problems are hidden behind balustrades or under balconies and may not be immediately noticeable.

Risk factors and warning signs

  • Balconies where support beams are constructed of untreated kiln-dried timber.
  • Balustrades and balconies clad with lightweight materials imitating concrete or masonry.
  • Balconies and balustrade tops where water pools and doesn’t drain away.
  • Balconies and balustrades that move or where there are damp spots, cracks or stains near where the balcony joins the main part of the building, or the balustrade joins the balcony.
  • Balustrades that have hand rails that penetrate into the house and/or balustrade wall.
  • Cracked plaster, mould growth or colour change in the plaster finish.

What to do 

If you think that your deck, balcony or balustrade may be at risk, you should stop using it until you have had it checked by a suitably qualified expert.

The following organisations will be able to identify people in your area with the necessary qualifications.

This information is published by the Ministry of Business, Innovation and Employment’s Chief Executive. It is a general guide only and, if used, does not relieve any person of the obligation to consider any matter to which the information relates according to the circumstances of the particular case. Expert advice may be required in specific circumstances. Where this information relates to assisting people: