Mould & Mildew in London Homes – Common Causes & Recommended Treatments

Mould & Mildew in London Homes – Common Causes & Recommended Treatments

3rd July, 2025

London sits on the Thames Valley Basin, which is a clay-based region that tends to retain water and this can cause damp, mould and mildew problems in buildings, especially older London properties. We hardly ever see the Sun these days and that means that wet ground is not drying out as it normally would and this is a major cause of rising damp.

What is mould?

Mould is a form of fungal growth that thrives in damp and humid conditions; lack of ventilation enables mould to release minute spores into the atmosphere and this is definitely a health hazard. There are different types of mould; black mould is by far the most dangerous, which can be fatal with prolonged exposure.

Mould is a major health hazard

Prolonged exposure to mould can cause serious respiratory disease, while it can also cause skin allergies such as eczema and red rashes. Mould is often concealed in dark places and it can be difficult to locate; tell-tale signs include a musky smell in the house and humid, stale air. Young children are particularly at risk as they tend to put everything in their mouth, while mould can also impact your pets. When health is concerned, it simply isn’t worth the risk, if you notice any signs of mould or mildew, call London Damp Surveys and arrange for one of our certified inspectors to assess your home.

Mould is destructive

Aside from the obvious health hazard, mould is a very destructive organism that feeds on organic materials like timber, drywall and insulating material, which over time, can compromise these materials. As mould spreads, it causes stains and discolouration, while also releasing deadly spores into the atmosphere; if you notice tell-tale signs of mould in your home, call London Damp Surveys and we can arrange for one of our certified damp surveyors to accurately assess the property for damp, mould, mildew and timber rot.

Lack of ventilation

If a property does not have adequate airflow, mould can thrive; it is important to create an airflow, which can be done by opening a few windows and/or the correct use of extractor fans. It is perfectly understandable that people do not want to open their windows in the cold weather, however, doing so every few days will help to reduce mould and mildew growth.

Recommended treatments

The best way to deal with mould is to call in a professional damp-proofing company in London, while we do not provide damp-proofing services, we do have a working relationship with the best teams in London. They use powerful industrial vacuums and scrubbers to completely remove harmful mould in a safe and effective manner, which is the safest way to remove mould and prevent it from returning. It is normal to section off areas of the property that suffer from mould, which prevents it from spreading.

Don’t delay, call London Damp Surveys on 0207 305 5997 anytime or fill in the form on this website.

Damp Survey Costs

Transparent pricing with no hidden fees for our independent, unbiased surveys.

Level 1

Level 1

£199 + VAT

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

Level 2

£299 + VAT

What’s included:

  • Everything in Level 1
  • Dry rot inspection
  • Wet rot inspection
  • Woodworm inspection
  • Damp information and prevention guide

 Survey Add Ons

Add On 1

£299 + VAT
Lab Analysis Of Plaster

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.

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Add On 2

£299 + VAT
Mould Lab Swab Testing, qPCR on DNA

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.

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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.

These are the tools we use

A damp meter

A 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

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.

Inspection Drone

Inspection Drone

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

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

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

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 Swab Test Kit

Mould Swab Test Kit

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.

Plaster Salt Analysis Lab

Plaster Salt Analysis Lab

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.