Basement Waterproofing in London – The Process Explained
The Victorian era saw cellars become very fashionable, which may have been due to the high cost of land; when building a house, you can only go so high, but adding a basement level adds significant living space. Terraced houses often rent out the basement as a studio flat, which helps to pay the mortgage, yet there are dangers when building underground, mainly damp and mould.
Basement Tanking
A much-needed service, basement waterproofing in London can be completed using waterproof plaster and render. The walls and ceilings would be stripped of old plaster and a sealant coat thickly applied, when this is dry, further coats of waterproof plaster are added, making sure each coat is fully dry before adding another. If the floors, ceiling and walls are all treated in this manner, you can rest assured that the interior will remain dry.
Cavity Drainage System
This is the best solution for a basement in a low-lying area, where water is present. The walls, floors and ceiling are stripped of plaster and studded membrane panels are fitted, which creates a cavity between the exterior wall and water is channelled through grooves in the floor that lead to a sump, where the water is pumped away. The cellar needs to be emptied while the work is carried out and within a few days, the interior is ready for occupation and will remain dry. We work closely with the top damp-proofing companies in London and they guarantee their work for a full 30 years.
Damp-Proofing Services
Although we do not offer damp-proofing services, we work closely with London’s top damp-proofing company that issues an unconditional 30-year guarantee on their work. If you are thinking of acquiring a London property with a basement, book an independent damp survey and we will send an experienced damp expert to assess the basement and the rest of the house. If damp is present, we will find it!
Inspecting a Basement for Damp & Mould
Terraced houses are especially at risk of rising damp, one of the adjoining properties could have a damaged DPC or they have built over the DPC and damp can travel a long way over time. Our damp specialists can pinpoint the source of moisture using digital equipment that is very sensitive and you will receive the survey report via email the following day. You won’t need to move anything for our surveyor to carry out their inspection and nothing will be disturbed; should remedial work be required, we can put you in touch with the best damp-proofing company in the city. The surveyor uses a borescope camera to inspect the dark corners and should you wish to discuss damp-proofing with the surveyor, they are always happy to help in any way they can. We are happy to offer an estimate for damp-proofing work and you can connect with our partner company that handles the damp-proofing work.
If you are planning to buy or sell a property in London, book an independent damp survey by calling 020 7523 5882 or complete the booking form on this website.
Damp Survey Costs
Transparent pricing with no hidden fees for our independent, unbiased surveys.
Level 1
What’s included:
- Inspection of walls
- Inspection of floors
- Inspection of ceilings
- Leak inspection of drains and plumbing
- Damp information and prevention guide
Level 2
What’s included:
- Everything in Level 1
- Dry rot inspection
- Wet rot inspection
- Woodworm inspection
- Damp information and prevention guide
Level 3 (Most Popular)
What’s included:
- Thermal Imaging
- Air humidity testing
- HD boroscope camera
- Brickwork pointing inspection
- DPC inspection
- Ventilation flow test on extractor fans
- 4K drone imagery roof, chimney stack
and guttering inspection - Structural condition inspection
- Inspection of walls
- Inspection of floors
- Inspection of ceilings
- Leak inspection of drains and plumbing
- Dry rot inspection
- Wet rot inspection
- Woodworm inspection
- Damp information and prevention guide
Survey Add Ons
Add On 1
Laboratory analysis Of plaster identifies hygroscopic salts such as chlorides and nitrates. which indicate whether damp is caused by rising groundwater or by plumbing leaks, This testing removes guesswork, allowing the exact source of moisture to be identified so the correct treatment is applied rather than carrying out unnecessary damp-proofing work.
Add On 2
qPCR DNA mould testing detects microscopic mould spores that are invisible during a normal inspection and van remain hidden behind walls, floors. or inside building rkaterials. It identifies the exact mould species present and the contamination level, allowing hidden mould problems to be confirrned and properly treated before they affect the property or occupants’ health.
Qualifications: All our surveyors are PCA and CSRT qualified for remedial treatments and also CSSW qualified for structural waterproofing.
Next day report: You will receive the report within 24 hours of the inspection taking place.
The survey fee will be deducted from the cost of any recommended repairs.
These are the tools we use
Damp Meter
A damp meter is a diagnostic tool used to detect and measure moisture levels within building materials such as plaster, brick, timber, and concrete.
Borescope camera
borescope camera is a small inspection camera attached to a flexible semi-rigid cable that allows you to see inside areas that are otherwise inaccessible.
Drone Inspection
A drone is a remotely operated aerial device equipped with a camera that allows visual inspection from above without the need for scaffolding or ladder.
Air Humidity Sensor
Air humidity sensor measures the amount of moisture present in the air, expressed as relative humidity (RH) in percentage. It helps determine whether indoor conditions are contributing to condensation, mould growth, or damp-related issues.
Thermal Imaging Camera
A thermal imaging camera detects temperature differences on surfaces by using infrared technology to produce a heat map image. In damp investigations, it helps identify cold spots, moisture intrusion, insulation defects, thermal bridging and leaks.
Air Flow Ventilation Detector
An air flow ventilation detector measures the movement and volume of air passing through vents, extractor fans, and air bricks. It confirms whether ventilation systems are working properly and achieving adequate air changes within a room. Poor airflow leads to trapped moisture, high humidity, condensation on cold surfaces, and ultimately mould growth.
Mould Lab Swab Testing
A mould swab test is carried out to confirm the presence of hidden mould growth and identify the specific species involved. Surface mould is not always visible, especially behind furniture, inside cavities, or within ventilation systems. Laboratory analysis of a swab sample determines whether active mould spores are present and what type they are, which helps assess potential health risks and decide the correct remediation approach rather than relying on visual assumption alone.
Lab Analysis of Plaster
Laboratory analysis of plaster is used to identify the type of salts present within the material, typically chlorides and nitrates. The presence and concentration of these salts help determine whether the moisture source is consistent with rising damp, ground contamination, or another forms [sic] of water ingress. such as mains water leak, This removes guesswork and prevents misdiagnosis, ensuring the correct remedial treatment is specified rather than applying unnecessary or ineffective solutions.
Contact Us
If you have some questions, please complete this form:
Book and Pay for a survey
If you are ready to book a survey and pay, please complete this form:
Contact Us
If you have some questions, please complete this form:
Book and Pay for a survey
If you are ready to book a survey and pay, please complete this form:
Contact Us
If you have some questions, please complete this form:
Book and Pay for a survey
If you are ready to book a survey and pay, please complete this form: