Damp Vs Mould: Key Differences Explained
Moisture levels are high in the UK, largely thanks to the wet climate we have, especially in London and the southeast. In this short article, we take an in-depth look at the key differences between damp and mould to help London homeowners gain a deeper understanding of moisture issues.
What is damp?
Dampness is cause by excessive moisture that eats away at brickwork, masonry, mortar, plaster and timber, which can cause significant damage to property. If you suspect that damp is present in your home, you can arrange for a qualified surveyor from London Damp Specialists to assess whether or not damp issues are affecting your property.
Rising & penetrating damp
These are the two types of damp and the difference is the source of the moisture; rising damp comes from the ground, while penetrating damp can affect a building at any location. Both forms of damp will penetrate building materials, causing a great deal of damage as it does.
Mould
Mould and mildew thrive in damp and humid conditions, especially window sills that have condensation forming on a regular basis. One sign that mould is present is a musky smell in the house and if you notice that, you need a damp proof specialist to assess the situation; mould growth can be found on walls, ceilings and timber window and door frames. Mould is actually a fungus that thrives in damp and humid environments and as a homeowner, you should keep your eyes open, looking for mould and mildew growth.
Identifying the source of the moisture
When you notice signs of dampness, it is imperative to find the source, which could be compromised DPC membrane, water entering external walls or even a leaking roof. There isn’t much point in treating the damaged materials if the source is unknown, as the problem will continue to arise. Our homebuyer survey is designed to provide you with a detailed report on the building and if we recommend remedial work, a quote is included with the survey.
The importance of good ventilation
Mould is caused by the presence of moisture and creating good ventilation is necessary to remove excess moisture from the air. This can be a combination of natural ventilation with open windows and extractor fans; when you take a hot bath or shower, open the windows until the condensation dissipates. Of course, people are reluctant to open their windows, as they lose the valuable heat, yet a few times a week, it is wise to generate an airflow which will help to dry out the air. At London Damp Specialists, we offer a ventilation flow test as part of a complete damp survey, which is designed to identify the cause of damp, mould and mildew.
To summarise, damp causes mould and mildew, as neither can arise without a damp and humid atmosphere; if you would like to have your home checked for damp and mould, call London Damp Specialist on 020 8528 3864 or fill in the online form on our website.
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:
- Everything in Level 1 & Level 2
- 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
- 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.
The survey fee will be deducted from the cost of any recommended repairs.
These are the tools we use
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 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
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 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
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.
Contact Us
If you have some questions, please complete this form:
Book and Pay for a survey
If you are ready to book a survey and pay, please complete this form:
Contact Us
If you have some questions, please complete this form:
Book and Pay for a survey
If you are ready to book a survey and pay, please complete this form:
Contact Us
If you have some questions, please complete this form:
Book and Pay for a survey
If you are ready to book a survey and pay, please complete this form: