Rooftop Waterproofing Membrane Replacement in Bondi Beach

When a flat concrete roof at the beach starts leaking into the unit below, the membrane is rarely the only thing at risk. Quin Projects was engaged to strip and rebuild the rooftop waterproofing on an occupied apartment building at Bondi Beach, in Waverley Council — removing the failed system and installing a new compliant one to keep the water out and protect the slab beneath. The problem. The building sits a short walk from the sand, carrying a flat concrete roof finished with an aged screed and membrane. Both had reached the end of their service life. Water was tracking through the tired membrane and saturated screed and showing up in the unit directly below. On a beachfront roof, that is where a maintenance issue turns structural — salt-laden wind, UV and ponding age a membrane hard, and once moisture reaches the reinforcement it drives the corrosion behind concrete cancer. The work. We ran the job as a controlled remedial sequence on an occupied building, with residents in place throughout. Perimeter scaffolding and edge protection went up first for safe work at height. We then removed the failed membrane and moisture-damaged screed back to bare concrete, inspected the slab, and mechanically ground the substrate for proper adhesion. Cracks and unsound areas were treated, bond breakers and fillets formed at the junctions, and a new screed laid to falls to drain the roof and stop ponding. Over the primed, prepared surface we installed a new compliant membrane, carrying it through every upturn, termination and penetration for a continuous, watertight barrier. All works met AS 4654.2 and the relevant National Construction Code provisions, and were installed to the manufacturer's specification. The outcome. Water ingress into the unit below has been resolved at its source, protecting that owner's finishes and removing the mould risk. Keeping moisture off the slab also prevents the corrosion, spalling and far costlier structural repairs that follow a neglected roof — a real reduction in future maintenance cost and genuine protection of the asset. The building left our hands with a clean, code-compliant rooftop built to last in a demanding coastal environment. Quin Projects is a registered Class 2 Building Practitioner (Licence BUP0003576) under the DBP Act 2020, specialising in remedial waterproofing for strata and commercial properties across Bondi Beach and the Eastern Suburbs. Leaking flat roof on your building? Call 1300 201 253 or book a site inspection.