Level 3 Damp Survey & QPCR Mould Analysis in Morden (SM4)

Back to all Case Studies
Level 3 Damp Survey & QPCR Mould Analysis in Morden (SM4)

This Level 3 damp survey and QPCR mould analysis was instructed for a two-storey house in Morden (SM4). The property owner sought an independent inspection to accurately diagnose internal mould growth and loose plaster. Commissioning an unbiased diagnostic assessment ensured the findings would be driven by objective laboratory data rather than sales targets.

About the Issue

The homeowner observed extensive mould growth spread across the bathroom walls and ceiling, as well as crumbling, loose plaster near the front entrance door. Fearing that water was leaking through the external masonry or rising from the ground, they worried the house suffered from widespread penetrating damp or structural decay.

The Challenge

Evaluating the property required a thorough Level 3 investigation combined with scientific mould sampling across all internal and external building components. The surveyor inspected the building from top to bottom, deploying a drone for high-level roof checks and taking direct diagnostic readings throughout.

Key evidence collected during the inspection showed:

  • Drone inspection confirmed the main roof covering was free of visible defects, while brickwork, pointing, drains and plumbing were fully sound with no dry rot, wet rot, or woodworm.
  • Moisture meter tests across the loose plaster near the front door returned completely dry readings, establishing the issue as a localised plaster failure rather than dampness.
  • Moisture readings on the bathroom walls and ceiling were dry, ruling out rising or penetrating damp, while an anemometer test recorded extractor fan airflow at an adequate 275.6 ft/min and internal humidity stood at 54.7%.
  • QPCR DNA mould swab analysis identified Aspergillus spp., Penicillium spp., Cladosporium spp. and a low presence of Stachybotrys spp., a profile consistent with surface condensation on cold walls rather than water ingress.

An external broken waste pipe at the rear produced visible green algae and fungal growth on exterior masonry, but diagnostic testing proved it was not affecting the interior environment. The investigation proved the bathroom mould was driven strictly by moisture-laden air from bathing condensing on cold external surfaces.

The Solution

Rather than carrying out invasive damp proofing, the diagnostic report outlined a targeted environmental management and thermal insulation strategy:

  • Install insulated (thermal) plasterboard to the bathroom walls and ceiling to raise surface temperatures and prevent condensation formation (Estimated Cost: £2,000).
  • Adopt ventilation habits such as keeping the bathroom door closed while showering and until humid air disperses, opening windows during and after bathing and running the extractor fan sufficiently.
  • Operate a dehumidifier on auto mode set to 50% humidity with windows closed to maintain healthy indoor moisture levels.

The Outcome

The homeowner achieved complete clarity, discovering that their house was entirely free from rising damp, penetrating damp, rot and structural leaks. By identifying the front entrance issue as simple plaster failure and the bathroom mould as a condensation defect, they avoided costly damp injection treatments and focused their budget on a £2,000 thermal upgrade.

Why This Case Matters

Surface mould and loose plaster are frequently misdiagnosed as structural damp by general inspectors or sales-driven contractors. Advanced diagnostic tools like QPCR DNA testing and thermal assessments isolate atmospheric condensation from ground moisture, protecting property owners from paying for unneeded damp proof course installations.

FAQ s
What did the QPCR DNA mould swab analysis reveal?

The analysis identified common condensation-related moulds, specifically Aspergillus spp., Penicillium spp., Cladosporium spp. and a low presence of Stachybotrys spp., confirming the growth was caused by surface condensation rather than structural dampness.

Does the broken rear waste pipe cause the bathroom mould?

No. Although the broken external waste pipe at the rear caused visible green algae and fungal growth on exterior masonry, testing confirmed it was not affecting the internal living spaces or contributing to indoor mould.

Is damp proofing required for the loose plaster at the front entrance?

No. Moisture meter readings confirmed no damp is present in that area, establishing that the loose plaster is a localised mechanical failure requiring simple plaster repair rather than damp treatment.

Ensure your property receives an accurate, laboratory-backed diagnosis before investing in major building repairs.

Equipment Used During Our Surveys

Professional Moisture Meter

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

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

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

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

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

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

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

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

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

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

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

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

Level 1

Basic Moisture Survey

Standard price: £299 + VAT

Special offer: £199 + VAT until the end of this month

Offer ends in--Days--Hours--Mins--Secs

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.

Click Here To Check Availability And Book Now
Level 2

Damp, Moisture and Timber Survey

Standard price: £399 + VAT

Special offer: £299 + VAT until the end of this month

Offer ends in--Days--Hours--Mins--Secs

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.

Click Here To Check Availability And Book Now

Specialist Survey Add-On Services

For complex damp investigations, we offer three specialised laboratory and environmental testing add-ons:

Add-On Service 1

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.

Click Here To Check Availability And Book Now
Add-On Service 2

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.

Click Here To Check Availability And Book Now
Air Quality, Gas, Vapour & Airborne Particle Screening
Add-On Service 3

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.

Click Here To Check Availability And Book Now

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:

Book Survey

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:

Book Survey

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:

Book Survey