5 Main Causes of Damp in London Homes
The South East of England is the wettest region of the UK, with a clay-based basin that runs along the River Thames and this causes many instances of rising damp in buildings. Every house should have a damp-proof course installed near ground level and if this is damaged in any way, moisture rises up the walls. A row of terraced houses can all be damaged by a single breach as damp travels along building materials, especially if it goes unnoticed.
Here are some of the common causes of damp and mould in London homes.
- Leaking roof – The roof protects the house from the harsh British climate and even a slight leak can have disastrous consequences, causing thousands of pounds in damage. Roof tiles get dislodged and can actually be lifted by gale-force winds, which is why you should have your roof inspected on a regular basis. Fascia and soffit boards are prone to decay, with driving rain and strong sunlight impacting the paint and this can be the onset of penetrating damp.
- Blocked guttering – The guttering is a critical escape channel for excess rainwater and if it should become clogged with wet leaves and twigs, this eventually leads to cascades of rainwater running down external walls and that is the beginning of penetrating damp. Our surveyor uses a mini drone to scan all guttering and blockages are removed.
- Compromised timber frames – Softwood was the material of choice for houses built pre-1980 and eventually, the timber degrades and damp takes hold. The ideal solution is to replace all doors and windows with aluminium double-glazed units that are made to fit the apertures.
- Damaged damp proof course – Damp creeps up from the ground and is halted by a damp proof course (DPC) that is sandwiched between lower brick courses; if the DPC is damaged, moisture can cross the barrier and will draw up through brickwork and render, causing significant damage. If you are planning to relocate to the capital and are looking at suitable properties, make sure you arrange for an independent damp survey from London Damp Specialists; if the building has damp issues, we will find it!
- Condensation – You would be surprised to learn how many London homes have an issue with condensation, which is caused when cold meets hot, typically found on windows, walls and other hard surfaces. Running hot baths causes water vapour to form and you should keep the bathroom door closed when running hot water and open a window to allow the moisture to escape. When cooking, switch on the canopy fan to suck up the odour and heat, which will prevent condensation. Our condensation experts can make recommendations to prevent the formation of water droplets.
We are ready to carry out a professional independent damp survey on your London home; call us on 020 7205 4886 or complete the survey request form on this website and we will be in touch shortly.
Damp Survey Costs
Transparent pricing with no hidden fees for our independent, unbiased surveys.
Level 1
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
What’s included:
- Everything in Level 1
- Dry rot inspection
- Wet rot inspection
- Woodworm inspection
- Damp information and prevention guide
Level 3 (Most Popular)
What’s included:
- Thermal Imaging
- Air humidity testing
- HD boroscope camera
- Brickwork pointing inspection
- DPC inspection
- Ventilation flow test on extractor fans
- 4K drone imagery roof, chimney stack
and guttering inspection - Structural condition inspection
- Inspection of walls
- Inspection of floors
- Inspection of ceilings
- Leak inspection of drains and plumbing
- Dry rot inspection
- Wet rot inspection
- Woodworm inspection
- Damp information and prevention guide
Survey Add Ons
Add On 1
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 On 2
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.
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
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 is a small inspection camera attached to a flexible semi-rigid cable that allows you to see inside areas that are otherwise inaccessible.
Drone Inspection
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 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
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
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 Lab Swab Testing
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.
Lab Analysis of Plaster
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.
