Case Study: Expansion Joint Waterproofing with Five-Layer Torch-On System and Asphalt Overlay
Location: Musgrave Centre, Berea, Durban
Project: Expansion joint waterproofing across parking deck ramps and driveways
Issue: Severe water ingress through degraded expansion joints in the parking deck, leading to interior water damage and long-term structural risk.
Overview:
Musgrave Centre, a major commercial and retail complex in Durban, was experiencing persistent water leaks through its rooftop parking deck expansion joints. During heavy rain, water penetration at these critical structural seams posed a risk to the underlying infrastructure and impacted the lower levels of the facility.
Problem Diagnosis:
The original expansion joint sealing had deteriorated over time and was no longer effective. Leaks were occurring at multiple transition points—particularly where vehicular traffic added additional strain. A durable, traffic-compatible solution was essential to both seal the joints and withstand the physical wear of a high-traffic parking environment.
Solution Implementation:
- Five-Layer Torch-On Waterproofing System:
Following specifications from our torch-on waterproofing supplier, we applied a multi-layered torch-on membrane system designed for flexibility, durability, and water-tightness over expansion joints. - Detailing at Critical Points:
The waterproofing was carefully lapped and sealed at the interface of walls, drains, and movement zones to ensure comprehensive coverage and joint flexibility. - Asphalt Overlay Protection:
Once the waterproofing layers cured, we applied a tar/asphalt topping. This not only provided mechanical protection from vehicle wear but also acted as a sloped surface to direct water away from the joints, minimizing pooling and pressure. - Traffic Compatibility:
The final surface was designed to integrate seamlessly with the existing deck, providing a continuous and vehicle-safe finish without disrupting traffic flow.
Outcome:
Prior to our intervention, the expansion joints at Musgrave Centre were leaking heavily during rainfall. By installing a five-layer torch-on waterproofing system, as specified by our suppliers, and finishing it with a tar/asphalt overlay, we successfully sealed the joints. The asphalt layer was designed to direct water away from the joints, preventing pooling and reducing water pressure on the membrane. The system effectively resolved the persistent leakage issue.