Water at the wall–floor junction
This junction is a common path when groundwater rises or drainage becomes overwhelmed.
What a useful investigation should establish.
A proposal is more useful when it explains the likely cause, the evidence, the affected construction and why a particular repair is being considered.
- Review site levels, drainage, groundwater risk and evidence from wet-weather events.
- Inspect the structure, joints, cracks, penetrations and any previous tanking or cavity-drain system.
- Agree the intended use of the basement and the acceptable internal environment.
- Plan drainage routes, sump capacity, alarms, backup measures and future maintenance where pumps are proposed.
Options, not assumptions01 02 03 04
How the repair may be approached.
Type A barrier protection
A continuous bonded barrier can resist water entry, subject to substrate preparation, continuity and detailing.
Type C drained protection
Studded membranes can direct ingress to perimeter channels and a suitable gravity outlet or sump-and-pump arrangement.
Combined protection
Higher-risk projects may benefit from compatible systems that do not share the same failure mode.
Maintainable drainage
Access points, pump servicing, high-level alarms and discharge arrangements are part of the system, not optional extras.
Important limitation
“Tanking” is often used as a general term, but barrier and drained systems behave differently. A specification should not be selected only from the visible damp patch. Groundwater risk, structure, use and maintenance must be considered as a complete design.