Waterproofing
Cavity drainage membrane systems
Drained protection systems that manage water rather than resisting it under pressure.
What the issue is
Cavity drainage membranes create a controlled air gap behind finishes, directing any water to a drainage channel and managed outlet. They are widely used where water pressure is present.
Common symptoms
- Water entering a basement floor or walls
- Previous tanking failure
- Recurring damp after finishing works
Likely contributing factors
- Groundwater pressure and fluctuating water levels
- Multiple entry points
- Structural cracks and joints
Conditions that may be mistaken for it
- Condensation within a finished basement
- Plumbing leaks behind finishes
How the issue should be investigated
- Assess water volumes and entry points
- Confirm drainage outlet options
- Review the structure and finishes
- Consider maintenance access requirements
Potential treatment or repair options
- Wall and floor membranes with perimeter drainage
- Sump and pump installation with alarm
- Battened or dubbed-out finishes
- Maintenance access provision
When treatment may not be appropriate
- Where a small localised repair would resolve the ingress
- Where no viable drainage outlet exists
Factors affecting the cost
- Floor and wall area
- Pump, sump and alarm provision
- Drainage connection and electrics
- Finishes and reinstatement
What to expect during an inspection
An assessment of the structure, water conditions, drainage options and how you intend to use the space.
Final recommendations always depend on the property, the inspection findings and the confirmed cause. Elevated readings alone do not confirm rising damp, not every mould problem requires extensive treatment, and damp-affected plaster does not always need replacing.
Frequently asked questions
Next step
Not sure which inspection you need? Start with a few questions.
Tell us what you are seeing and we will set out what is likely, what is uncertain and which inspection would answer the question. Speak to us on 0333 335 6152 if you would rather talk it through.