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Balcony, Podium & Planter Box Leak Detection
Trafficked waterproofing over habitable space — the single most common source of water ingress complaints in strata buildings. We find which defect is responsible without removing tiles to guess.
The tiles are not the waterproofing. The membrane underneath them is.
Tiles and grout were never intended to be waterproof, and they are not. Water passes through them routinely and collects on the membrane below, where it should run to a drain and leave. A balcony is, in effect, a shallow tray — and it works perfectly until water reaches a point where the tray is broken.
When that happens the water does not appear beneath the defect. It runs along the top of the membrane, finds a penetration or a slab edge, enters the structure, and surfaces on the soffit or in the unit below — often not the one directly underneath. Water shows up where it stops moving, not where it got in.
Five defects account for almost every case
The membrane stops short at the upturn
Waterproofing has to turn up the wall behind the tiles and terminate above finished surface level. Where it stops too low, or was never dressed properly into the wall junction, water tracks behind it as soon as the deck ponds even slightly. The most common single cause, and completely invisible once tiling is complete.
The drain outlet was never properly connected
A puddle flange bonds the membrane to the drain body so water reaching the membrane can actually leave. Where one was omitted, badly bedded or has corroded, water reaches the drain, runs past it, and enters the slab at the exact point the slab was penetrated. Extremely common on older buildings.
Something has been drilled through the membrane
Balustrade base plates, privacy screens, awnings, planter fixings, clothes lines, air conditioning brackets. Each is a hole through a waterproof layer, and the sealant around it has a service life in years, not decades. Balustrade fixings are the worst offenders because they also carry load and move.
A movement joint was tiled straight over
Concrete moves, tiles move at a different rate. Where control joints were not carried up through the tile bed and grout, the tiles crack in a straight line and water uses the crack as an entry point. A crack that runs dead straight and parallel to a building line is almost never random.
The door threshold sits too low
Australian practice requires a step-down or an adequate drainage detail between a balcony and the internal floor. Each re-tiling reduces that step until wind-driven rain simply runs indoors. Easy to identify, expensive to fix properly.
Planter boxes and podium decks
A planter box is a balcony with permanently saturated soil sitting on it and roots working into every joint. Podium decks add scale: large areas of membrane, multiple falls, expansion joints, and habitable space or a carpark directly beneath. Both fail in the same ways as a balcony, but they hold water continuously rather than intermittently — so a defect that would take years to show on a balcony shows in months.
Drainage cell, root barrier and the membrane termination at the box wall are the details worth investigating first, and they are the ones most often value-engineered out during construction.
How the investigation runs
Baseline before any water
- Thermography across the affected ceiling and soffit
- Moisture mapped through the build-up, not at the surface
- Recorded before testing so later readings mean something
Staged flood and spray testing
- Drain plugged, deck held under water, ceiling monitored
- Drain then tested separately to isolate the puddle flange
- Directional spray on threshold, balustrade and wall above
- Tracer dye where the path needs proving
Close inspection of the underside
- Rope access to soffits and balustrade fixings
- Photographed at arm's length, not from the ground
- Efflorescence and delamination recorded and located
The unit below. Nothing on the ceiling reads as a leak to the eye. The thermogram shows the wet area running well past the faint mark, and shows the direction it came from — which is what turns a guess into a place to test.
What you get at the end
A report that names the defect, shows the moisture distribution supporting the conclusion, records which tests eliminated what, and defines a repair scope a committee can put to a vote or an insurer can assess. Not an opinion — a documented process of elimination.
Rectification by the same crew
Highpoint Solutions holds a QBCC waterproofing licence, so the crew that traced the ingress can strip, prepare and re-waterproof the deck. No hand-off to a second contractor, and no gap where the investigator blames the repairer and the repairer blames the investigator.
Scoped from a real investigation rather than a visual guess, the repair is usually smaller than the owner feared — and it only has to be done once.
Read the full guide to balcony and podium leaks in strata buildings →