Balconies are some of the hardest-working parts of an apartment building’s exterior. Each one combines a waterproofing system, drainage, a concrete or framed structure and a safety barrier, all fully exposed to weather and to daily use by residents. When any one of those fails, the result is usually a leak into the unit below, damage to the slab, or a barrier that can no longer be relied on.
This article covers the defects that come up most often on Melbourne balconies, the warning signs residents and committees can spot, and what to do about them.
Waterproofing and drainage
Most balcony leaks start with the waterproofing membrane under the tiles or topping, or with how water is drained off the balcony.
Warning signs:
- water stains, bubbling paint or mould on the ceiling of the balcony or unit below
- efflorescence (white, powdery salt deposits) seeping from grout lines or the slab edge
- tiles that are loose, drummy or cracked
- water pooling for hours after rain instead of draining away
- blocked, undersized or missing floor wastes and overflows.
Why it happens: membranes age and crack, are punctured when fixings are drilled through them, or were never properly turned up at walls and door sills. Drainage fails when floor wastes block or when the fall of the balcony sends water toward the building instead of away from it.
The junction at the balcony door sill is a particularly common leak point. If the membrane does not run up behind the door frame, water reaches the inside of the unit or the slab edge.
The slab and its edges
Balcony slabs are exposed on top, underneath and at the edge, so they are where concrete cancer most often appears. Look for rust stains on the soffit or edge, cracking along the slab edge, and any concrete that has broken away. Debris on the balcony below or on the ground is a reason to act straight away.
Balustrades and handrails
Balustrades are a life-safety element, so defects here deserve priority even when they look minor.
Warning signs:
- any movement or flex when the rail is pushed
- corroded, loose or missing fixings at the base or wall connections
- cracked or chipped glass panels, or missing glass clamps and spigot covers
- rust staining around post bases, which can mean water is getting into the fixing and corroding it out of sight
- gaps under or between barrier elements that look larger than when the building was new.
Corrosion at the base of a post can be well advanced before it shows on the surface, which is why fixings are checked closely during an inspection rather than judged from a distance.
Who looks after balconies
On many Victorian strata buildings the balcony structure, waterproofing and balustrades sit with the owners corporation as common property, while tiles and finishes may be treated differently depending on the plan of subdivision and the rules. Checking the plan early avoids disputes about who pays once a defect is found.
What to do
- Treat barrier defects as urgent. If a balustrade moves, has damaged glass or corroded fixings, restrict use of the balcony until it has been assessed.
- Trace leaks properly. A leak in a ceiling can come from the balcony above, a window, or the wall between them. Controlled water testing is the way to prove which; see how to find the real source of a leak.
- Inspect balconies as a set, not one by one. Defects tend to repeat across a building because the same details and products were used throughout.
- Plan the fixes. Membrane and drainage repairs, sealant replacement and coating work are predictable enough to budget in a maintenance cycle.
Summit Facades inspects balcony slabs, waterproofing details, drainage and balustrade fixings as part of every facade inspection. Findings are documented in a facade defect report with each defect rated, photographed and given a recommended action, and recurring items can be rolled into a planned maintenance program.
