_{This project involved comprehensive waterproofing of a newly constructed basement car park located beneath a multi-story commercial complex. Given the below-ground location and exposure to hydrostatic pressure, a combination of pre- and post-construction systems was implemented to achieve full structural protection against water ingress.}

Site Condition and Project Considerations

• The structure consisted of a reinforced concrete raft foundation, perimeter retaining walls, and vehicle access ramps

• The high water table posed a significant risk of water intrusion and chloride ingress from surrounding soil and chemical agents

• Expansion joints, pipe penetrations, and wall-to-slab junctions were observed as key vulnerability areas
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Solution Implementation

‍1. Base Slab Waterproofing

• A bitumen membrane sheet waterproofing system was installed below the raft foundation during the construction phase.

• Sheets were torch-applied with fully sealed overlaps to form a continuous and impermeable barrier against water migration from below.
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2. Retaining Wall Protection

• The vertical retaining walls were externally coated using a spray-applied polyurea waterproofing membrane, offering seamless, high-elasticity protection.

• All pipe penetrations and details were reinforced using liquid-applied membrane systems to ensure watertight transitions and adaptability to complex geometries.

3. Crack and Joint Injection

• Post-construction monitoring revealed hairline cracks and moisture seepage at key joints, which were successfully sealed using hydraulic resin injections.

• These injections formed watertight seals deep within the concrete structure and prevented future water pathways from developing.

4. Internal Surface Protection

• To extend service life and reduce the risk of chemical degradation, a cementitious waterproofing coating was applied to interior wall surfaces and slab edges.

• This also provided additional resistance to carbonation and moisture vapor transmission.
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Summary and Outcome‍

Systems Applied: Bitumen Membrane Sheet Waterproofing (Foundation); Spray-Applied Polyurea Protective Coatings (Retaining Walls); Hydraulic Resin Injections (Cracks & Joints); Cementitious Waterproofing Solutions (Internal Surfaces).

The integrated system delivered a robust waterproofing envelope, eliminating seepage, condensation, and surface dampness throughout the basement car park. The use of both sheet-based and spray-applied systems ensured high-performance coverage across both large and detailed areas.

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