Level 3 Subfloor & Leak Diagnostic Survey in Thames Ditton (KT7)

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.

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.

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.

Description: This test uses a specialist air-sampling pump to collect airborne mould spores from inside a property, with outdoor air sampling where appropriate for comparison. Samples are sent to an accredited laboratory to assess airborne mould spore concentrations and identify mould types where the analysis allows.

Value: Unlike a surface swab test, which checks for mould DNA on a specific surface, air sampling investigates mould spores circulating in the air, including where visible mould growth may not be present. This test helps investigate suspected airborne mould contamination and supports damp and mould assessments so that appropriate remedial action can be determined.

This service can be beneficial when:

• Suspected airborne mould contamination is present without obvious visual signs.
• Occupants experience persistent musty odours or unexplained respiratory irritation.
• Recurrent condensation, poor ventilation, or high humidity issues are suspected.
• Verification of indoor air quality is needed following a leak or water ingress.
• Confirmation is required on circulating spore levels before or after remedial works.

Note: Air mould sampling assesses active airborne spores at the time of testing. Results are analysed alongside external baseline samples, structural moisture readings, ventilation performance and visible property conditions. Survey fee credited when repairs are completed by us.

Description: A detailed aerial roof survey using high-resolution 4K drone imagery to inspect roof coverings, chimney stacks, guttering and other external roof features. The survey provides clear photographic and video evidence of visible defects, damage, deterioration and potential maintenance issues, including areas that are difficult or unsafe to access from ground level.

Value: Findings are documented with supporting imagery, helping identify visible problems and assess the external condition of the roof and associated structures without the need for direct physical access or costly scaffolding. This ensures external defects causing water ingress and penetrating damp are accurately pinpointed.

This service can be beneficial when:

• Roof coverings, chimney stacks, flashings, or parapets cannot be safely viewed from ground level.
• High-level penetrating damp, ceiling staining, or chimney damp is present inside the property.
• Guttering, valleys, or rainwater goods are suspected of overflowing or leaking into masonry.
• Purchasing or maintaining a multi-storey or period property with complex roof structures.
• Clear photographic and video evidence of external defects is required before carrying out repairs.

Description: Our biological and organic contamination testing service identifies biological residues and potential contamination within residential and commercial properties. Depending on the suspected contamination, samples are collected using surface swabs, targeted sampling methods, or other appropriate techniques and submitted to a suitable laboratory for analysis.

Value: Scientifically identifies residues that cannot be confirmed by visual inspection alone. Testing provides verified laboratory evidence to investigate contamination from bodily fluids, human and animal waste, drainage failures and bacterial activity, ensuring remedial cleaning and decontamination works are targeted effectively.

Testing categories can include:

• Human bodily fluids: Blood and suspected blood residues; urine and urine residues; semen and suspected semen residues; saliva and saliva residues; and other suspected bodily fluid contamination (subject to laboratory capability).
• Human waste and associated contamination: Faecal matter and suspected faecal residues; biological residues associated with human waste; and indicators of faecal contamination where suitable laboratory tests are available.
• Animal waste and biological residues: Animal faeces and droppings; urine residues from domestic animals; animal bodily fluid residues (subject to laboratory capability); and biological contamination associated with animal activity.
• Bacterial contamination: General bacterial contamination; selected bacterial indicators associated with faecal contamination; and specific bacterial organisms where targeted laboratory testing is available.
• Other biological and organic residues: Suspected biological deposits on floors, walls and other surfaces; organic residues associated with human or animal activity; and mixed biological contamination where the material cannot be readily identified visually.

This service can be beneficial when:

• A property has experienced sewage backups, soil pipe leaks, or escape of water.
• Unexplained foul or persistent organic odours remain present.
• Contamination from animal pests, droppings, or domestic pets is suspected in structural voids.
• Trauma, severe neglect, or tenancy turnover requires formal clearance and verification.
• Clear laboratory confirmation is required before and after decontamination or remedial works.

Note: The appropriate test will depend on the material suspected, the surface being tested and the level of identification required. The survey fee is credited when repairs are completed by us.