The Leak Lands in Someone Else Flat
A failed balcony rarely damages the balcony. The membrane is under the tiles, the tiles look fine, and the water goes down into the ceiling of the unit below.
That means the person who discovers the problem is not the person who owns the balcony, and the person who owns the balcony has no visible reason to believe anything is wrong. It is the most common source of neighbour disputes in Cape Town apartment blocks, and it is why balcony leaks tend to go unaddressed for years while the damage compounds.
It also complicates responsibility. In a sectional title scheme the balcony slab is typically common property while the tiled surface may be an exclusive use area, so who pays for what depends on the scheme rules and its registered plans rather than on common sense. Getting a proper diagnosis in writing matters more here than anywhere else on a building, because it is the document that settles the argument.
We do not give legal or body corporate advice. What we do is establish exactly where the water is coming from, in writing, with photographs, so whoever has to make the decision can make it on facts.
Why Balconies Fail
The waterproofing is under the tiles, not the tiles. Tiles and grout are not a waterproof layer. Water passes through grout routinely, and the membrane beneath is what stops it. When people re-grout a leaking balcony, they are treating the symptom.
Falls. A balcony must fall away from the building to an outlet or a drip edge. Many do not, either through original construction or through a re-tiling job that levelled the surface. Water then sits against the threshold and finds the door.
The threshold detail. Where the balcony meets the sliding door is the single most common failure point. The membrane has to be carried up behind the door frame, and the finished balcony level has to sit below the internal floor level. Where it does not, driving rain pushes water straight under the track.
Outlets and scuppers. Blocked, undersized, or absent entirely on older balconies that were designed to drain over the edge.
The slab itself. Coastal balconies spall exactly like coastal roofs. Rusting reinforcement lifts the concrete, and any membrane bonded to it comes away. Balcony soffits and edges are often the first place spalling shows on an Atlantic Seaboard building, because they are thin, exposed on multiple faces and frequently have minimal cover to the steel.
Balustrade fixings. Every bolt through the balcony surface is a penetration through the waterproofing, and they are almost never detailed properly.
Cape Town Balconies Specifically
Cape Town balconies take an unusual combination of loads.
Winter rain arrives horizontally. North-westerly fronts at 50 to 65kph drive water at the threshold rather than dropping it on the floor. A balcony that drains perfectly under vertical rain fails at the door in a front, because the water is being pushed at a junction that was never designed for pressure.
Sea-facing glass and sliding doors. The Atlantic Seaboard characteristic large sliding doors onto balconies put a wide, low-tolerance junction directly in the path of the weather. Perished silicone in a door track is a leak in a front.
Salt and spalling. Continuous chloride exposure on exposed slab edges, on top of the general vulnerability of thin balcony slabs. This is the pattern across Sea Point and Bantry Bay.
The summer south-easter works at anything loose, lifts poorly bonded membrane edges under tiles, and abrades exposed sealant.
