Pre-Winter Damp Inspections – Why They Are Important for London Homes

Pre-Winter Damp Inspections – Why They Are Important for London Homes

3rd July, 2025

The UK winters are legendary; while we don’t have much snow, we do experience heavy rain and damp conditions, which seem to go on forever. Damp and mould are a very real threat to London properties and in this short article, we offer useful information on how to inspect your home for damp and mould prior to the freezing winter months.

Exterior inspection

The damp proof course is close to the ground level; a thick bitumen strip that is inserted between brick courses during the initial build and this DPC membrane prevents moisture from attacking the building. Check all walls close to ground level, looking for crumbling mortar and moss growth; take a screwdriver to poke the mortar to see if it is crumbling and should you notice damp is present, book a damp inspection with London Damp Surveys.

Roof inspection

Of course, the roof on your house is not exactly accessible, yet it does need to be inspected on a regular basis; missing or broken roof tiles leave the internal roof structure open to water damage, while the soffit and fascia boards should be firmly in place, as they protect the roof line from rain penetration. Guttering should be free from obstructions, as this is a crucial escape route for excess rainwater; wet leaves and small twigs can cause a blockage, so make sure the channel is free from all objects. Take a flashlight and climb into the loft, examining all timbers for signs of damp, mould and timber rot.

Interior inspection

Check all walls and ceilings looking for damp patches, tide marks and other signs of damp, including condensation, which forms when there is excessive moisture in the air; another reason for condensation is when extreme temperatures meet on a surface like walls or glass. Check the integrity of all timber window and door frames, looking for signs of woodworm, wet and dry rot.

Penetrating damp

Damp that penetrates exterior walls is a very real threat to London homes, therefore, you should regularly inspect the exterior walls, looking for signs of damp presence. Driving rain can erode masonry and mortar and over time, this can lead to moisture penetrating into the building. If damp reaches the interior walls, you might notice peeling wallpaper and bubbling paintwork.

Professional damp inspections

At London Damp Surveys, we are proud to serve all London Boroughs by providing professional damp, mould and timber rot inspections to London home and business owners. This is the best way to ensure that your home is free of damp, mould and timber rot; you receive a detailed written report within 24 hours of survey completion and if you are planning to make an offer on a London property, it is paramount to have the structure surveyed for damp issues.

Call us on 0207 305 5997 or fill in the form on this website and find out for sure whether or not your home is under attack from moisture.

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.