Transforming a Damp, Sub-Street Vault into a Completely Dry, Protected Space
Located beneath the pavement in the heart of Kensington, London, historical coal holes and sub-street vaults present unique waterproofing challenges. Due to their direct contact with external street levels, surrounding soil, and fluctuating moisture tables, these underground spaces are notoriously vulnerable to water ingress, damp penetration, and condensation.
For this recent project, our expert team at Crystal Damp Proofing & Basements Ltd was brought in to tackle a severely damp, raw brick vault that suffered from water seepage and structural degradation.
The Challenge: Raw Brick & Moisture Infiltration
Upon initial inspection, the vault featured exposed, aging brickwork with active damp patches, flaking mortar, and rubble accumulation on the floor. Surface solutions or quick fixes would not suffice; the location beneath the pavement required a robust, dual-protection waterproofing strategy to guarantee long-term performance.
The Technical Solution: Combined Type C and Type A Waterproofing System
To completely eradicate moisture and future-proof the structure, we implemented a comprehensive multi-stage waterproofing approach:
- We cleared all debris, stripped back compromised materials, and prepared the structural surfaces to address the source of water ingress rather than just masking the symptoms.
- Applied directly to the masonry, the Type A waterproof render system creates a dependable internal barrier that bonds with the substrate, effectively resisting hydrostatic pressure.
- : To manage any remaining water seepage, we installed a high-density polyethylene (HDPE) cavity drain membrane system along the walls and vaulted ceiling. Its unique dimpled design creates a secure air gap, safely channeling controlled water management down to a discreet drainage and sump pump system.
- The floor was finished with a durable, level structural concrete slab, tying the entire waterproofing envelope together into a seamless, dry, and secure environment.
