A Guide to Choosing the Right Damp Specialist in London

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.