Decks, balconies, balustrades and handrails

Maintaining your deck:

  • Look for any compression or deformation of the supporting posts, beams or joists. Decayed timber will feel soft and spongy.
  • Check underneath decks or balconies and look for deterioration, particularly where timber members join. 
  • Make sure the deck or balcony structure is properly fixed to the building.
  • Check the base of timber posts for rot.
  • Check brackets and bolts for signs of rust.
  • Ensure posts are securely anchored to the foundation in concrete or attached to concrete footings using proprietary metal brackets.
  • Make sure water does not pool at the base of a post or wall support.
  • Check handrails and balustrades to ensure they are not rotted, corroded, loose or unstable.
  • Be aware certain timbers are more susceptible to external environments, requiring frequent inspections.

If you suspect a problem with your balcony or deck, contact a building surveyor, structural engineer or registered builder, architect or building inspector.

What can affect balconies/decks?

There are many things owners should be aware of that can affect the structural adequacy of a balcony over time.

These may include:

  • Termites- Nillumbik has been declared a termite prone area.
  • Wet rot
  • Seaside and corrosive effects
  • Loadings - such as large plant pots, water features etc provide additional loads for a balcony to support, for which it may not have been designed.

What can I do to prolong the life of my deck?

All timber should be protected against weathering - such as painting, staining or applying water repellent preservatives etc. Clear finishes may provide limited protection against weathering, as many finishes deteriorate when exposed to sunlight.

A number of design features can be incorporated to extend the life of a balcony constructed of concrete, or having an impervious sheet floor finish. These include:

  • providing adequate falls across the surface – minimum 1 in 60
  • ensuring a minimum 100mm difference between the finished balcony surface and indoors
  • providing a durable floor surface membrane and appropriate flashing
  • providing effective drainage and ensuring careful detailing around drains to ensure inlets are below the level of the surrounding balcony and can be cleaned easily
  • providing overflows in case drains become blocked, or their capacity is exceeded
  • providing correct handrail fixing
  • providing 35mm minimum clearance between the base of wall claddings and the surface of the balcony
  • durability of concrete, adequate cover and protection of reinforcing steel.

If there is anything suspicious about a balcony’s stability, you are advised to avoid the area and, most importantly, restrict access to the balcony. It is recommended you contact a structural engineer or other suitably qualified building practitioner, who will be able to inspect the balcony to determine the full scale of the problem.

Further information regarding the maintenance of decks and balconies can be obtained from the Victorian Building Authority.

When are balustrades or handrails required?

Balustrade or handrails must be provided along the side of any stairway or ramp, any floor, corridor, hallway, balcony, verandah, or the like, and along the side of any path to a building if it is not bounded by a wall and the surface level beneath is more than one metre away.

This requirement does not apply to a window opening.

Construction of balustrades or handrails

Balustrades or other barriers must be installed in accordance with the following:

The height must not be less than;

a) 1mtr above the floor of any access path, balcony, landing or the like; or
b) 865mm above the nosings of the stair treads or the floor of a ramp.

A transition zone may be incorporated where the balustrade or other barrier height changes from 865mm on the stair flight or ramp to 1mtr at the landing.

Openings in balustrades (including decorative balustrades) or other barriers must be constructed so that any opening does not permit a 125mm sphere to pass through it and for stairs, the space is tested above the nosing line.

Where the finished floor level is more than 4mtr above the surface beneath, any horizontal elements within the balustrade or other barrier between 150mm and 760mm above the floor must not facilitate climbing.

Wire balustrade

For this purpose, a wire balustrade consist of a series of tensioned wire rope connected to either vertical or horizontal supports.A wire balustrade excludes wire mesh fences and the like.

Where wire balustrade is proposed to be used, it must be constructed in accordance with Clause of Volume 2 of the Building Code of Australia. 

Care needs to be taken to ensure that wire tension will be maintained during the life of the balustrade. In some situations, it may be necessary to incorporate "lock-off" devices to prevent loosening of the wire. Likewise, if a threaded anchor bears against a soft wood post or rail, the anchor may indent the post or rail, thus loosening the wire.

Temperature effects on the tension of the wire may be significant but there is little that can be done to allow for temperature variation in service. The shorter the wire span, the lesser the effect will be.

Further information regarding the maintenance of decks and balconies can be obtained from theVictorian Building Authority website.


The information provided regarding the requirements balustrades and handrails is intended to be used as a guide or interpretation only and cannot be used for legal purposes.