How to Carry Out a Damp Survey – Essential Information from Professionals
You might be planning to buy a property in London, or you simply want to find out if damp is present in your home, whatever the reason, if you want to check a property for damp issues, we offer essential information in this short article.
Equipment that you will need
To effectively inspect your London home for damp and mould, you will need the following:
- Moisture meter – This device measures the moisture content in building materials and there are two types, namely pinned and pinless. The pinned variety allows you to measure moisture content in building materials such as timber and plaster; they can be sourced and purchased online.
- Humidity tester – A device that measures the amount of humidity in the air; a hygrometer is an important piece of kit that every damp surveyor would own.
- Flashlight – Necessary to illuminate dark corners, places where mould is likely to grow. Make sure you check every square inch of the loft, as damp can cause serious damage to roof timbers.
- Screwdriver – Used to scrape and prod exterior materials, looking for signs of damaged brickwork, masonry and timber.
- Ladders – An important aspect of inspecting a building is checking the roof, especially cleaning out the guttering; if the guttering becomes blocked, excess rainwater seeps down exterior walls, which can cause penetrating damp.
- Peephole camera – Also known as a borescope camera, this device allows you to get a close-up view of hard-to-reach places. Under floorboards, staircases and inside cupboards should be inspected carefully.
Damp inspection techniques
Perhaps the best place to start is the roof, as this can be a source of moisture penetration; all it takes in a few missing roof tiles and a heavy storm to cause serious damage to a roof interior, which is largely made from timber. Exterior walls also need to be inspected thoroughly, looking for signs of damp damage, especially at ground level, where rising damp can occur.
Interior damp inspection
One sure sign that moisture is damaging your home is damp patches on walls and ceilings, tide marks, peeling wallpaper and bubbling paint are all signs that damp is present. If window condensation is normal, the air is very humid, something that encourages mould and mildew; ventilation removes condensation, so opening windows at specific locations makes a good airflow and that dries out the air. Be aware of an earthy smell in the house, which is an indication of damp and mould; this is the right time to contact us at London Damp Specialists; we have been providing damp proofing in London for many years, a family-owned business with a fantastic reputation in the industry.
Independent damp survey
Rather than doing all of the above, you can London Damp Specialists on 020 7458 4864 or fill in the online form and we can arrange for one of our certified damp surveyors to inspect your home. You can get a professional report on the status of your home and if we recommend remedial work, we quote a competitive price.
It makes total sense to be proactive when it comes to moisture and rising damp, protect your valuable asset with top quality damp proofing solutions.
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.
Equipment Used During Our Surveys
Equipment Used During Our Surveys
Purpose:
Takes comparative moisture readings from walls, ceilings, floors and timber to identify abnormal moisture patterns.
Common Uses / Notes:
Used when investigating rising damp, penetrating damp, condensation and leaks. Readings support the survey but are not a diagnosis on their own.
Subsurface Moisture Meter
Purpose:
Detects moisture beneath the surface of suitable building materials.
Common Uses / Notes:
Helps determine whether moisture is confined to surface finishes or extends into the building fabric.
Non-Damaging Moisture Scanner
Purpose:
Scans surfaces for hidden moisture without causing damage.
Common Uses / Notes:
Ideal for decorated walls, ceilings and flooring where pin testing would be undesirable.
High-Resolution Borescope Camera
Purpose:
Inspects hidden or difficult-to-access areas without opening up large sections of the building.
Common Uses / Notes:
Used beneath floors, inside cavities, behind walls and around pipework to identify damp, leaks, decay and concealed defects.
4K Aerial Inspection Drone
Purpose:
Captures high-resolution images of roofs and other inaccessible external areas.
Common Uses / Notes:
Inspects roof coverings, chimneys, flashing, gutters, valleys, parapets and high-level masonry. Subject to weather, safety requirements and flight regulations.
Atmospheric Humidity Sensor
Purpose:
Measures indoor relative humidity levels.
Common Uses / Notes:
Helps assess condensation and mould risk alongside temperature, ventilation, heating patterns and room usage.
Gas Detection Monitor
Purpose:
Screens for certain airborne gases where unusual odours are present.
Common Uses / Notes:
May detect gases associated with drainage, combustion or flammable substances. Does not replace inspection by a Gas Safe registered engineer where gas appliances or pipework are involved.
Thermal Imaging System
Purpose:
Identifies temperature differences across building surfaces.
Common Uses / Notes:
Helps locate cold spots, thermal bridging, insulation defects and areas associated with concealed moisture. Results always require further investigation to confirm the cause.
Basic Socket and RCD Tester
Purpose:
Performs limited electrical checks during comprehensive surveys.
Common Uses / Notes:
Can identify basic socket wiring issues, AC voltage and RCD operation. It is not an Electrical Installation Condition Report (EICR).
Chemical Vapour Testing Device
Purpose:
Screens for airborne volatile organic compounds (VOCs) and formaldehyde.
Common Uses / Notes:
Used where chemical odours, emissions from materials or indoor air-quality concerns are suspected after leaks or refurbishment.
Fine Air Particle Counter
Purpose:
Measures airborne particulate matter (PM1.0, PM2.5 and PM10)
Common Uses / Notes:
Assists with investigations involving dust, smoke, mould concerns, post-construction contamination and indoor air quality following water damage.
Extraction and Air-Movement Tester
Purpose:
Measures the performance of extractor fans and mechanical ventilation systems.
Common Uses / Notes:
Used in kitchens, bathrooms and utility rooms to identify poor ventilation that may contribute to condensation and mould growth.
Survey Levels and Equipment Provided
Basic Moisture Survey
Standard price: £299 + VAT
Special offer: £199 + VAT until the end of this month
The Level 1 survey provides a basic assessment of the main accessible internal surfaces. It is most appropriate for simple, localised damp concerns where advanced testing is not required.
Equipment Included
- Professional damp meter
Survey Checks
- Accessible walls
- Accessible floors
- Ceilings
- Visible plumbing and drainage leak inspection
- Damp-control and prevention information
Suitable For
This survey is suitable for a customer who has found an isolated damp patch, suspects rising damp in a limited area or wants a straightforward check of the property’s accessible surfaces.
Only a standard damp meter is included. Customers requiring deep moisture detection, timber inspection, thermal imaging or roof inspection should select a higher survey level.
The survey fee will be deducted if we carry out the recommended work.
Damp, Moisture and Timber Survey
Standard price: £399 + VAT
Special offer: £299 + VAT until the end of this month
Level 2 includes everything in the Level 1 inspection and adds deeper moisture detection, non-invasive scanning and timber assessment.
Equipment Included
- Professional damp meter
- Deep-reading moisture meter
- Non-invasive moisture scanner
Survey Checks
- Accessible walls, floors and ceilings
- Visible plumbing and drainage leak checks
- Subsurface moisture readings
- Non-invasive scanning of appropriate materials
- Accessible underfloor and subfloor checks
- Wet rot inspection
- Dry rot inspection
- Woodworm inspection
- Damp prevention information
Suitable For
This level is intended for customers who require a more detailed inspection of dampness and timber condition. It is appropriate when moisture may be concealed within building materials or beneath accessible flooring.
The survey may identify evidence of timber decay or wood-boring insects and assess moisture in locations that cannot be properly examined with a surface meter alone.
Level 2 is particularly useful for homebuyers and sellers who want more information about damp and timber before completing a transaction.
The amount paid for the survey will be deducted from repairs undertaken by us.
Full Damp and Property Condition Survey
Standard price: £499 + VAT
Special offer: £399 + VAT until the end of this month
Level 3 is our most detailed inspection. It combines the checks from Levels 1 and 2 with advanced diagnostic technology, ventilation measurements and external roof-level assessment.
Equipment Included
- Professional damp meter
- Deep-reading moisture meter
- Non-invasive moisture scanner
- Thermal imaging camera
- Indoor humidity sensor
- HD borescope camera
- Airflow and ventilation tester
- 4K inspection drone
- Socket and RCD testing device
Survey Checks
- Accessible walls, floors and ceilings
- Visible plumbing and drainage
- Deep moisture investigation
- Non-destructive moisture scanning
- Accessible floor voids and subfloors
- Wet rot, dry rot and woodworm
- Infrared thermal imaging
- Indoor relative humidity
- Extractor-fan performance
- Borescope examination where suitable
- Visible damp-proof course
- External brickwork and pointing
- Roof coverings and junctions
- Chimney stacks and flashing
- Guttering and rainwater systems
- High-level exterior areas
- General visible structural condition
- Basic socket and RCD screening
- Drone photographs, subject to safe flying conditions
Suitable For
The Level 3 survey is recommended for buyers, sellers and existing owners who want the most extensive moisture assessment available.
It is especially useful for older properties, houses with several reported defects, basement buildings and cases involving damp, mould, leaks, poor ventilation, timber decay or roof problems.
The inspection considers the property as a connected building rather than examining only the visible damp patch. A roof or gutter defect, for example, may allow water to enter at a high level and appear some distance away internally.
The drone component provides valuable information about roofs, chimneys, parapets and guttering that cannot normally be seen from the ground. These areas may contain hidden repair costs capable of affecting a property purchase.
Identifying damage before buying can help the purchaser budget correctly, request further specialist advice or use the findings during negotiations. Even a relatively small roof defect may cost more to repair than the difference between the survey packages.
If we complete the recommended remedial work, your survey payment will be credited against the price.
Specialist Survey Add-On Services
For complex damp investigations, we offer three specialised laboratory and environmental testing add-ons:
Laboratory Analysis of Plaster Samples
Price £299 + VAT
Description: Small plaster samples are extracted from affected masonry walls and submitted to an independent testing laboratory. The lab analyses the sample for hygroscopic salts (specifically nitrates and chlorides).
Value: Scientifically differentiates true rising damp (which deposits ground salts over time) from surface condensation or lateral penetrating damp. Ensures that remedial recommendations are based on chemical analysis rather than surface meter readings alone.
This service can be beneficial when:
- The cause of low-level dampness is disputed.
- Moisture-meter readings are inconsistent.
- A property has undergone previous damp-proofing.
- Old plaster continues to attract moisture.
- Independent laboratory evidence is required.
- Several possible moisture sources are present.
Note: Salt analysis is only one part of the investigation. Results must be assessed alongside the location of moisture, condition of the masonry, external ground levels, damp-proof course and potential plumbing or rainwater defects. Requires minor invasive plaster sampling (the only add-on requiring material removal). Survey fee credited when repairs are completed by us.
Mould Identification & qPCR DNA Testing
Price £299 + VAT
Description: Surface swab samples are collected and sent to an accredited laboratory for advanced qPCR DNA analysis. Identifies exact mould species, measures spore concentrations and detects hidden fungal growth behind furniture, within void spaces, or under floorboards.
Value: Provides precise scientific data regarding mould toxicity and contamination levels, helping establish the exact scale of cleaning, drying and structural remediation needed.
Laboratory mould testing may be useful when:
- There is an unexplained musty odour.
- Visible mould repeatedly returns.
- Water damage occurred previously.
- Mould is suspected behind cupboards or furniture.
- Contamination may be present in a concealed location.
- The visible extent of growth is uncertain.
- Independent results are needed.
- Remediation work is being planned.
Note: The results can provide a clearer indication of whether contamination appears minor, concentrated or potentially widespread. This information may be used when deciding the scale of cleaning, removal, drying or remedial work required. Testing should be combined with an investigation of the moisture source. Removing visible mould without resolving the underlying condensation, leak or ventilation problem may allow it to return. Survey fee credited against subsequent remediation works completed by us.
Air Quality, Gas, Vapour & Airborne Particle Screening
Price £299 + VAT
Description: Comprehensive environmental air testing including:
- Indoor environmental quality – IAQ
- Volatile organic compounds – VOC and TVOC
- Formaldehyde – HCHO
- Fine airborne particles – PM1.0, PM2.5 and PM10
- Dust and smoke particles
- Sewer gases – H2S, NH3 and CH4
- Flammable gases – CH4 and C3H8
- Carbon monoxide – CO
- Hydrogen sulphide – H2S
- Ammonia – NH3
- Oxygen measurement – O2
- Ventilation and stale-air assessment
- Drain-smell investigation
- Chemical-odour investigation
- Air checks following a leak or flood
- Combustion-related screening
- Building-material off-gassing assessment
- General airborne pollutant monitoring
Value: Pinpoints invisible airborne hazards, toxic sewer gases, chemical off-gassing and foul odours resulting from damp or trapped water.
This service can assist when investigating:
- Persistent foul smells
- Suspected sewer or drain odours
- Chemical smells
- Stale indoor air
- Odours following water damage
- Possible stagnant water
- Building material emissions
- Fine dust after construction work
- Poorly ventilated rooms
Note: Unpleasant odours can have several possible sources. Measurements for specific gases, compounds and particles may help identify which source requires further investigation. The assessment is a screening service and does not replace specialist gas-safety, environmental or medical testing where this is necessary. Survey fee credited against subsequent repair works completed by us.
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: