What is Damp Proof Course (DPC)?
Every house should have a protective damp proof course (DPC) layer in the walls of the property. That will help prevent moisture from move up the walls and into the living area from the ground below and surrounding the wall foundations. If your damp proof course DPC has failed or in some cases non-existent, then this is commonly referred to as rising damp.
What is rising damp?
If you live in a property with no Damp proof course layer, or DPC Injection to your walls then often ground water and in some cases drain water will be absorbed and rise up through a capillary action. This moisture then rises through the walls, mortar, plaster, concrete and over time will make your internal plaster pop or crumble, often creating damp spots on internal walls, and eventually lead to mould.
As Damp Specialist London the most common question we get asked is “what can you do to combat a rising damp problem?”
Damp Proof Courses (DPC) Slate or Black Plastic
When a house or extension is first built it is easy to combat potential “rising damp problem” and today forms part of standard building regs. A specialist damp proof layer is fitted to create barrier between the bricks at floor level, and the bricks above, stopping that moisture from climbing up the walls and entering the home.
With some old London properties, we find slate was used as a kind of DPC material, however today most modern builders will use durable water-resistant material and most widely available method these days is a specialist damp proof plastic membrane.
You can find your DPC by taking a look at your external wall. Look down at ground level and look up about 6 inches or so up the wall. Somewhere around here you will see a thin black line of either slate or plastic running horizontally across the brick work. This is your DPC. Before any damp proofing treatments are conducted our surveyors make a thorough check and survey around the whole of the house – water can be clever and enter in multi DPC failed areas.
Don’t think you have any DPC?
If your home was built ins the last 100, the majority of homes will have some form of DPC, however some DPC’s get damage, degrade or through vermin, building or home improvement work become susceptible to damp penetration.
Fortunately, with London Damp Specialists, we can fix failed DPC and take fast remedial actions to clear and future prevent rising damp penetration.
If you think that your home may have a damp problem and your home is showing signs of rising damp problems, then we recommend getting a survey from a damp expert.
How to fix rising damp and damaged DPC’s
There are now a wide array of different chemicals and specialist damp proofing gels that can be ‘injected’ into your walls to create a protective DPC. Often, this type of treatment is cheaper than installing a physical Damp proof course into an existing wall.
We offer a professional and qualified damp surveyor, with the right equipment to complete the initial assessment.
How much does DPC injection cost?
We often find we are working on a typical London Home, such as a Victorian mid terrace, in which a Damp proof Course DPC injection might cost as little £500- £800. As you might imagine prices can vary greatly considering the length of wall that required treatment, how far the damp has risen and any additional remedial action we need to take. The DPC injection process is simple, and once the job is done, it will last for many years.
If you would like to find out more or discuss your specific rising damp issues or failed damp proof course: 020 8528 3864 or [email protected]
Professional Damp Diagnostic Equipment
Electronic Moisture Meter
Purpose:
Takes comparative moisture readings from accessible walls, floors, ceilings and other surfaces to identify abnormal moisture patterns.
Common Uses / Notes:
Helps the surveyor map affected areas and identify patterns associated with rising damp, penetrating moisture, condensation and potential leaks. Readings support the survey but are not a diagnosis on their own.
Deep-Reading Moisture Meter
Purpose:
Investigates below the immediate surface of building materials without requiring extensive removal of finishes.
Common Uses / Notes:
Helps locate moisture within walls, beneath accessible floors, inside subfloor areas and deeper within the building fabric where hidden moisture is suspected.
Non-Destructive Moisture Scanner
Purpose:
Checks for changes in moisture beneath walls, ceilings and flooring non-invasively without puncturing or damaging the finished surface.
Common Uses / Notes:
Ideal for decorated walls, ceilings and flooring where pin testing would be undesirable. Useful for tracing water migration paths and comparing dry areas against suspected damp sections.
High-Definition Borescope Camera
Purpose:
Provides a close visual inspection of concealed or difficult-to-access spaces without opening up large sections of the building.
Common Uses / Notes:
Used beneath floors, inside wall cavities, behind linings and around hidden pipework to uncover leaks, hidden moisture, timber decay, or construction defects with minimal disturbance.
4K Aerial Drone
Purpose:
Captures high-resolution images of roofs, chimney stacks and other inaccessible high-level external areas.
Common Uses / Notes:
Inspects roof coverings, chimney stacks, flashing, guttering, parapet walls, valleys, high-level brickwork and difficult elevations to reveal defects linked to penetrating damp and water ingress. Subject to weather, safety rules and flight regulations.
Indoor Humidity Monitor
Purpose:
Measures the amount of moisture held within the indoor air (relative humidity and temperature).
Common Uses / Notes:
Helps determine whether high ambient humidity, insufficient ventilation, or surface condensation could be contributing to black mould growth and damp conditions.
Infrared Thermal Imaging Camera
Purpose:
Displays surface temperature variations across walls, floors and ceilings.
Common Uses / Notes:
Assists in identifying cold bridging, condensation risk, insulation irregularities, thermal patterns and hidden water leaks. Interpreted alongside physical moisture readings rather than treated as proof of damp on its own.
Ventilation and Airflow Tester
Purpose:
Tests the extraction performance and airflow velocity of mechanical extractor fans and ventilation outlets.
Common Uses / Notes:
Assesses extractor fans in kitchens, bathrooms and utility rooms to determine whether moisture-producing areas have sufficient extraction rate (L/s or m3/h) to control humidity, condensation and mould risk.
Multi-Gas Detection Equipment
Purpose:
Screens indoor air to identify certain gases present within the property.
Common Uses / Notes:
Supports investigations involving drain smells, suspected sewer gases (H2S, NH3, CH4), combustion concerns (CO, O2) and flammable gases (CH4, C3H8). Does not replace testing or certification by a Gas Safe registered engineer.
VOC and Chemical Vapour Monitor
Purpose:
Screens the air for Volatile Organic Compounds (TVOC/VOC) and chemical substances such as formaldehyde (HCHO).
Common Uses / Notes:
Useful when investigating unusual chemical smells, building material emissions/off-gassing, conditions following water damage, or general indoor air quality concerns.
Fine Particle Monitor
Purpose:
Measures airborne material and particle concentrations across precise size ranges, including PM1.0, PM2.5 and PM10.
Common Uses / Notes:
Supports investigations involving fine dust, smoke, poor indoor air conditions and environments affected by post-leak damage or extensive mould contamination.
Socket and RCD Testing Device
Purpose:
Provides limited, basic electrical safety and protective circuit screening during the inspection.
Common Uses / Notes:
Helps identify certain socket wiring problems, confirms the operation of Residual Current Device (RCD) protection and detects AC voltage in damp areas. Does not constitute a full electrical inspection or an Electrical Installation Condition Report (EICR).
Equipment & Inspection Levels
Essential Damp Survey
Standard price: £299 + VAT
Promotional Price: £199 + VAT (Limited Time Offer)
Repair Deduction: Full survey cost deducted if remedial work is instructed.
The Level 1 survey is an entry-level inspection of the main accessible areas. It is intended for relatively straightforward concerns involving visible damp, suspected rising damp or isolated moisture patches.
Equipment Provided
- Electronic damp meter
Areas and Checks Included
- Accessible walls
- Accessible floors
- Ceilings
- Visible drain and plumbing leak checks
- Damp information and prevention guidance
Recommended For
This option is suitable when a customer needs a basic assessment using a standard damp meter. It can be used for a general check or where there is a simple and clearly defined moisture concern.
The inspection covers accessible internal surfaces, drains and plumbing but does not include the advanced diagnostic instruments provided with the higher survey levels.
The survey price will be deducted if we undertake the recommended remedial work.
Enhanced Damp & Timber Survey
Standard price: £399 + VAT
Promotional Price: £299 + VAT (Limited Time Offer)
Repair Deduction: Full survey cost deducted if remedial work is instructed.
The Level 2 survey includes the Level 1 inspection together with deeper moisture investigation and checks for timber-related deterioration.
Equipment Provided
- Electronic damp meter
- Deep-reading moisture meter
- Non-invasive moisture scanner
Areas and Checks Included
- Accessible walls, floors and ceilings
- Visible drain and plumbing leak checks
- Wet rot inspection
- Dry rot inspection
- Woodworm inspection
- Deeper moisture readings from suitable building materials
- Non-destructive moisture checks beneath accessible floors and within subfloor areas
- Damp information and prevention guidance
Recommended For
It is appropriate for concerns involving wet rot, dry rot, woodworm, concealed dampness or moisture below finished surfaces.
The combination of deep-reading and non-invasive instruments allows the surveyor to gather information from subfloors, beneath accessible floorboards, behind suitable panelling and within other reachable concealed areas without unnecessary dismantling.
The Level 2 survey is a good choice for buyers and sellers who require a more detailed damp and timber assessment before proceeding with a property transaction.
The survey charge will be deducted from the cost of remedial work undertaken by us.
Comprehensive Property Moisture Survey
Standard price: £499 + VAT
Promotional Price: £399 + VAT (Limited Time Offer)
Repair Deduction: Full survey cost deducted if remedial work is instructed.
The Level 3 survey is our most comprehensive inspection. It incorporates the Level 1 and Level 2 services and adds advanced diagnostic equipment, ventilation testing and high-level external inspection.
Equipment Provided
- Electronic damp meter
- Deep-reading moisture meter
- Non-invasive moisture scanner
- Infrared thermal imaging camera
- Indoor humidity monitor
- HD borescope camera
- Airflow and ventilation tester
- 4K inspection drone
- Socket and RCD testing device
Areas and Checks Included
- Accessible walls, floors and ceilings
- Visible drains and plumbing
- Wet rot, dry rot and woodworm
- Deep moisture testing
- Accessible subfloor moisture checks
- Thermal imaging
- Indoor humidity measurement
- Borescope examination where appropriate
- Brickwork and pointing
- Visible damp-proof course
- Extractor fan airflow
- Roof coverings
- Chimney stacks
- Flashing and guttering
- High-level external components
- General visible structural condition
- Basic socket and RCD screening
- 4K drone photographs where flight conditions permit
Recommended For
This option is suitable when a customer needs a basic assessment using a standard damp meter. It can be used for a general check or where there is a simple and clearly defined moisture concern.
The inspection covers accessible internal surfaces, drains and plumbing but does not include the advanced diagnostic instruments provided with the higher survey levels.
The survey price will be deducted if we undertake the recommended remedial work.
Specialised Laboratory Testing Add-Ons
Laboratory Analysis of Plaster Samples
Price £299 + VAT
(The cost of this add-on is deducted from your repair bill if we carry out the recommended remedial works).
Small plaster samples are carefully taken from affected walls and sent to an independent laboratory to analyse the concentration of hygroscopic salts (chlorides and nitrates).
Why it matters: Hygroscopic salts are carried by ground moisture during rising damp and remain in plaster even after masonry dries.
Diagnostic value: Differentiates true rising damp from condensation, rainwater penetration, or temporary plumbing leaks.
Note: Salt analysis can be particularly helpful when moisture-meter readings alone do not provide a sufficiently clear diagnosis. It may assist in distinguishing possible rising damp from condensation, water penetration or residual contamination caused by a historic leak. The results are considered together with the moisture profile, construction of the building, external ground levels, condition of the damp-proof course and other survey observations. This is the only additional service requiring minor invasive work because physical plaster samples must be collected. If we undertake the recommended remedial work, the survey cost will be deducted from the cost of that work.
Laboratory Mould & qPCR DNA Analysis
Surface swab or lift samples are submitted to an accredited laboratory for advanced qPCR DNA testing to identify exact mould species and spore concentrations.
Why it matters: Identifies toxigenic species (e.g., Stachybotrys chartarum) and concealed mould growth behind dry lining or furniture.
Diagnostic value: Establishes whether mould contamination is localised or widespread, enabling precise environmental remediation planning.
This service may be beneficial where:
- A persistent musty smell is present
- Mould repeatedly returns after cleaning
- The property has experienced previous water damage
- Contamination is suspected behind furniture or inside cupboards
- Occupants have concerns about the indoor environment
- The extent of visible mould is unclear
- Independent laboratory evidence is required
Note: The results can help establish whether contamination appears isolated or more widespread. They may also assist with planning appropriate cleaning, removal, drying, ventilation or moisture-control measures. Laboratory mould testing does not replace the need to investigate the moisture source. Mould is normally a symptom of excess moisture, condensation, leakage or inadequate ventilation, so the underlying cause must also be identified. If we carry out the recommended work, the survey fee will be deducted from the cost of that work.
Gas, Vapour & Airborne Contaminant Screening
Price £299 + VAT
(The cost of this add-on is deducted from your repair bill if we carry out the recommended remedial works).
Comprehensive environmental air quality screening for properties with persistent odours, post-flood contamination, or air quality issues.
Screening includes:
- Indoor air-quality assessment – IAQ
- Volatile organic compounds – TVOC/VOC
- Formaldehyde – HCHO
- Fine airborne particles – PM1.0, PM2.5 and PM10
- Dust and smoke particles – PM1.0, PM2.5 and PM10
- Sewer gas screening – H2S, NH3 and CH4
- Flammable gas screening – CH4 and C3H8
- Carbon monoxide – CO
- Hydrogen sulphide – H2S
- Ammonia – NH3
- Oxygen levels – O2
- Stale-air and ventilation assessment – IAQ and TVOC
- Drain odour investigation – H2S, NH3 and CH4
- Chemical smell investigation – TVOC, VOC, HCHO and NH3
- Post-leak air and surface-condition checks – PM2.5 and TVOC
- Combustion gas screening – CO, O2 and CH4
- Building-product off-gassing assessment – TVOC and HCHO
- General pollutant screening – PM1.0, PM2.5, PM10 and TVOC
Diagnostic value: Pinpoints the source of foul drain odours, chemical off-gassing and stale air problems linked to poor ventilation. It is also useful when a property contains a persistent foul, stale or unexplained smell. Odours can originate from damp building materials, stagnant water, contaminated drains, sewer gases, mould-related conditions or chemical vapours. Targeted screening helps narrow down the possible source and supports further investigation.
Note: Screening results do not replace specialist gas, environmental or medical assessments where these are required. The survey charge will be deducted if London Damp Specialists completes the recommended remedial work.
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: