A balcony or patio slab above a living area is the hardest-working waterproofing detail on any Johannesburg North property. It is walked on, furniture is dragged across it, water pools on it after every storm — and when it fails, the damage happens in the room below, usually long before anyone connects the two. The

Walk any street in Greenside, Melville or Parkhurst and you will see them: parapet walls framing the roofline of a 1930s or 1940s home. They give these houses their character — and they are, by a distance, the most common reason the ceilings below them stain every summer. Why parapets leak when the roof is