As people head out to their holiday homes - or look at the home maintenance jobs they might be doing over the summer holidays – checking the deck or balcony should be on the ‘to do’ list.

Certain kinds of decks and balconies are at greater risk from leaks and decay; those supported by untreated kiln-dried timber or where water pools on the surface rather than draining freely.

In extreme cases, structures have not only rotted but collapsed.

Where timber balustrades are enclosed within claddings or the floor is covered with a waterproof surfacing, it’s possible for water to leak in behind the surfaces and create decay and corrosion.

If the property has a balcony or deck, consider these risk factors.

• Has untreated kiln-dried timber been used for structural support?
• Is the balustrade clad with lightweight materials with a plaster finish?
• Are there any holes or cuts in the waterproof floor surfacing?
• Is there flat access, with no step, where the deck meets the building doorway?
• Does water pool on the surface?
• Do cantilevered joists (or other joists that penetrate the exterior wall) lack flashings?

Look at the barrier or balustrade. These factors all pose further risk.

• Is it clad with lightweight material with a plaster finish?
• Does it lack a waterproof capping?
• Does it have a flat top where water sits?
• Does it have a railing where water is able to leak down screw holes?

Warning Signs

Balconies and decks that move when walked on.

• Dampness or stains where the balcony, balustrade or deck joins the main part of the building.
• Cracks, particularly near junctions, joints and corners.
• Balustrades or railings that wobble.
• Balustrades where damp spots or stains can be seen on the cladding.
• Interior water damage or any visible change to interior surfaces next to, or directly beneath the balcony or deck.

Open timber decks constructed with durable treated timbers are less likely to be of concern. However, check that there is no corrosion (balustrades and posts should not wobble) and keep an eye out for timber decay.

Remember that all types of deck, balcony and balustrade must be designed and constructed to meet the requirements of the New Zealand Building Code and be maintained throughout their lifetime.