Damp and the Many Ways it Can Damage your London Home

Damp and the Many Ways it Can Damage your London Home

3rd July, 2025

The UK has a damp climate and with rainfall statistics on the rise and endless cloudy days, these climatic changes allow for damp and mould to thrive and in this short blog, we offer information on the different ways that damp can damage a London property.

  • Rising damp – Moisture that rises from the ground is a primary cause of building damage; London properties should have a damp proof course, a strip of bitumen that is inserted between lower courses of brickwork that effectively prevents moisture from rising up the walls. There are other ways to stop damp rising from the ground; chemical DPC can be injected into walls and when set, provides a waterproof seal. You should closely inspect the exterior walls close to ground level, looking for signs of rising damp, such as moss growth and crumbling mortar and masonry.
  • Mould & mildew – Mould and mildew present a serious health hazard, especially black mould, which can be fatal! Mould thrives in a damp, still environment and it releases minute spores that can be inhaled and cause respiratory conditions. Mould comes in a range of colours, from black to green to a light brown/greyish colour. If your home has mould, you should have the property surveyed by London Damp Surveys.
  • Condensation – If a room has excessive moisture content, condensation can form; aside from bathroom and kitchen condensation, caused by running hot water and cooking. The best way to dissipate condensation is to open windows to create an airflow; heating the affected rooms can dry out the atmosphere, so you should turn on the central heating at least one time per week, especially in rooms that are not being used. Condensation on the walls is a sign that moisture is entering the building and this needs to be investigated by professional damp inspectors.
  • Internal roof damage – A leaking roof can quickly lead to the internal roof timbers becoming damaged; inspect upstairs walls and ceilings looking for damp patches and tide marks, which are signs of penetrating damp.
  • Timber damage – Damp causes damage to timber and you should inspect all timber for signs of woodwork and timber rot, both wet and dry. Check all window and door frames; go into the loft with a flashlight and closely inspect all timbers to ensure that damp is not present. Woodworm is a very real threat; certain beetle species burrow tiny holes in wood where they lay their eggs, which are usually a pale cream colour. Preservative can be applied to timber that protects against woodworm and rot, which comes in both wet and dry forms.

At London Damp Surveys, we are dedicated to assisting London homeowners by accurately assessing damp and providing a detailed written report, along with remedial work recommendations. Give us a call on 0207 305 5997 during office hours or leave your details in the form on this website and we will arrange for one of our qualified damp surveyors to carry out a thorough inspection of your home.

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.

Add to Survey

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.

Add to Survey

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.