Advanced Negative-Side Waterproofing: Elevator Shaft Remediation
Managing water ingress in below-grade structures like elevator shafts requires specialized engineering, especially when the exterior is inaccessible. This project involved a critical "negative-side" waterproofing intervention for a closed elevator shaft that suffered from persistent leaks.
The Challenge
The elevator shaft experienced continuous high-pressure water infiltration from the surrounding soil. With no access to the exterior (positive side), we had to engineer a solution from the inside — known as negative-side waterproofing. The existing concrete showed severe deterioration: water stains, exposed rebar, and compromised structural bonding.
The Result
A permanently sealed elevator shaft with no active leaks. The structural integrity of the concrete was restored, and the multi-layer system ensures long-term protection against hydrostatic pressure. The shaft is now ready for mechanical equipment installation.
Our Solution
Structural Bonding with Sikadur-31 & 32
High-modulus, high-strength epoxy resins were used to ensure a perfect, moisture-tolerant bond between the existing substrate and repair materials. These epoxies cure even in damp conditions, critical for active-leak environments.
Crack Injection & Surface Sealing
All active cracks and joints were injected with polyurethane and epoxy resins to stop water flow at its source. The wall-to-ceiling junctions received special attention with elastomeric sealants.
Cementitious Waterproofing Membrane
A multi-layer negative-side waterproofing membrane was applied to all interior surfaces, creating a continuous barrier capable of withstanding hydrostatic pressure from the soil side.
Materials & Technology
How We Solved It
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