Urgent repair
Call to discuss the fault
Call to discuss active water ingress or extensive recurring moisture damage. Report damp and mould promptly to the responsible landlord or building manager.
Call 020 4571 4235Mayfair · Damp & mould investigation
Basement leaks & waterproofing assessment in London
Water entering a basement or lower-ground room?
Tell us what needs doing. We’ll organise the right help and explain the price.
All London boroughs · Homes, landlords & managed properties · Your area: West London
- Direct enquiries
- Clear scope and price
- You approve extra work
- Your project price
- Request a scoped quote Materials, preparation and access included as agreed. VAT shown in your quotation.
- Need help urgently?
- Call for availability Tell us your postcode, work required and access arrangements. Sending a form does not book attendance.
Investigation is quoted to scope. Specialist surveys, laboratory testing, waterproofing systems and reinstatement are separate unless expressly included. A visual inspection is not a structural or mortgage survey.
Below-ground water problems require assessment of the construction and any existing waterproofing or drainage system. Mayfair can coordinate the appropriate specialist enquiry and an agreed investigation before remedial work is priced.
The work, explained
What the visit can include
- Review the water-entry history and existing records.
- Arrange specialist assessment of the relevant system.
- Separate investigation, design and remedial work.
Investigation is quoted to scope. Specialist surveys, laboratory testing, waterproofing systems and reinstatement are separate unless expressly included. A visual inspection is not a structural or mortgage survey.
Help us plan your visit
What to include in your enquiry
- Provide previous waterproofing documents if available.
- Say whether pumps or alarms are installed.
- Describe access and whether water is currently entering.
Choose the closest job
More damp & mould investigation
Not sure why a wall feels damp?Damp surveys & investigationScope, costs & enquiry →Mould keeps returning around windows or walls?Condensation & recurring mould investigationScope, costs & enquiry →
A wall becomes wet after rain?Penetrating damp investigationScope, costs & enquiry →Damp or damaged plaster near the skirting?Rising damp assessment & investigationScope, costs & enquiry →Water entering through an outside wall?External wall leak investigationScope, costs & enquiry →A price for the agreed work
Investigation is quoted to scope. Specialist surveys, laboratory testing, waterproofing systems and reinstatement are separate unless expressly included. A visual inspection is not a structural or mortgage survey.
Specialist investigation and any designed waterproofing solution need their own quotation.
From enquiry to finished work
- Send the fault or task list and your postcode.
- Agree the scope, price and appointment with Mayfair.
- We arrange the appropriate trade and explain any extra work for your approval.
Workmanship cover, duration and exclusions are set out in the written quotation. Product warranties follow their manufacturer’s terms.
Direct to Mayfair · No chat required
Request your service quote.
Tell us what’s happening and where. We’ll help you work out the next step and what it costs.
No account needed. No payment to send an enquiry.
- Your details
- Review and send
- Request status
This is not an emergency response service. Do not wait for an online reply if there is an immediate risk to people or property.
How quotes and orders work →Help us plan your repair
Water entering a basement or lower-ground room?
Provide previous waterproofing documents if available.
London coverage
Damp & mould investigation across London
We serve all 32 London boroughs and the City of London. Choose an area to see repair options, visit preparation and a direct enquiry route.
Example work, explained
Finding the cause of a damp wall
- The problem
- A damp patch, peeling finish or recurring staining needs a cause established. A meter reading or photograph alone cannot distinguish every source of moisture.
- The work involved
- Review when the patch appears, nearby plumbing, external defects, ventilation and the building's construction. Agree further investigation and source repairs from the findings.
- Checks and next steps
- Explain the likely source, any limits of the inspection and the plan for repair and drying. Surface treatment or redecorating is considered once the underlying problem is addressed.
Need similar work at your West London property? Tell us the symptoms and access arrangements.
Search by neighbourhood, borough or postcode. August 2026 ONS data gives district-level suggestions, including when you enter a full postcode. Districts can cross boroughs; send your street and full postcode when booking.
Neighbourhood repair guides
Damp & mould investigation in Clapham →Damp & mould investigation in Balham →Damp & mould investigation in Tooting →Damp & mould investigation in Hammersmith →Damp & mould investigation in Kensington →Damp & mould investigation in South Kensington →Damp & mould investigation in Knightsbridge →Damp & mould investigation in Shoreditch →Damp & mould investigation in Dalston →Damp & mould investigation in Brixton →Damp & mould investigation in Greenwich →Damp & mould investigation in Woolwich →Damp & mould investigation in Walthamstow →Damp & mould investigation in Leyton →Damp & mould investigation in Wembley →Damp & mould investigation in Finchley →Damp & mould investigation in Ilford →Damp & mould investigation in Deptford →Damp & mould investigation in Blackheath →Damp & mould investigation in Brockley →Damp & mould investigation in Angel →Damp & mould investigation in Highbury →Damp & mould investigation in Soho →Damp & mould investigation in Pimlico →Damp & mould investigation in Camden Town →Damp & mould investigation in Muswell Hill →Damp & mould investigation in Ealing Broadway →Damp & mould investigation in Acton →Damp & mould investigation in Twickenham →Damp & mould investigation in Surbiton →Damp & mould investigation in Bermondsey →Damp & mould investigation in Dulwich →Damp & mould investigation in Fulham →Damp & mould investigation in Shepherd's Bush →Damp & mould investigation in Hampstead →Damp & mould investigation in Chiswick →Damp & mould investigation in Wimbledon →Damp & mould investigation in Richmond →Damp & mould investigation in Battersea →Damp & mould investigation in Putney →Damp & mould investigation in Canary Wharf →Damp & mould investigation in Stratford →Damp & mould investigation in Mayfair →Damp & mould investigation in Marylebone →Damp & mould investigation in Chelsea →Damp & mould investigation in Notting Hill →Damp & mould investigation in Belgravia →
London postal districts can overlap borough and county boundaries. London coverage includes London addresses using outer postal prefixes; it does not mean every address in the surrounding counties is included.
Questions about damp & mould investigation
Is basement tanking included in an ordinary repair visit?
No. A waterproofing system requires a suitable assessment and defined specialist scope; it is not covered by a small-repair call-out offer.
Can you tell the cause of damp from a photograph?
Photos help describe the symptoms but do not prove the cause. Building condition, moisture sources and the history of the problem need consideration before a treatment is recommended.
How much does basement leaks & waterproofing assessment cost?
Specialist investigation and any designed waterproofing solution need their own quotation. We provide a quote including VAT for the agreed work.
Do you cover all of London?
Yes. We cover all 32 London boroughs and the City of London. Select a borough below or include your full postcode when requesting a quote. The appointment depends on the required work and available specialist.