How to prevent penetrating damp
Penetrating damp is one of the common types of damp that can cause issues in a home, and is usually caused by water and moisture from outside the home making its way into the exterior. Due to the high amount of wet weather that we will often get in the UK, penetrating damp can often be a problem in UK homes, particularly in older properties that were not built with damp-proofing in mind. Penetrating damp can occur for several reasons and is more common when the bricks are porous and allow the water through, in homes that do not have a cavity wall, and in homes that are poorly maintained and might have problems like cracks in the exterior brickwork or windows where the sealing is deteriorating. Penetrating damp can be a serious issue if left unchecked and can lead to bigger problems in your home including water damage and mould.
What is Penetrating Damp?
As the name suggests, penetrating damp is a type of damp problem in the home which occurs when the moisture makes its way through from the exterior of the home. This can happen for many reasons. Porous bricks that have not been treated with a damp-proof coating, for example, might allow water to get through where it will impact the internal walls after rainfall. Anything that allows moisture to get in through the walls of your home can lead to a penetrating damp problem.
What is Penetrating Dampness Caused By?
Poor home maintenance is one of the common causes of penetrating damp. Water that is able to get through cracks in the exterior walls or damage to the roof and window frames can quickly lead to penetrating damp. It can also be caused by porous bricks that have not been treated with a waterproofing solution, leaving them susceptible to allowing the water through where it might affect the interior of your home, especially if there is no cavity wall. Homes with a solid brick wall rather than a cavity wall tend to be more susceptible to penetrating damp, since there is no air gap to trap the moisture on the outer wall when it gets through. Some common causes of penetrating damp include:
- Cracked rendering: When the render is damaged, water will be allowed to penetrate through it and this can result in further smaller cracks.
- Blocked downpipes and guttering: This may direct water towards the home and encourage penetrating damp. Fortunately, unblocking or repairing the gutters is usually an easy way to fix the problem.
- Damage to the roof: Anything that could cause water to get in through the roof like damaged or slipped roof tiles can result in water getting in.
- Damaged windows: Windows that are aging or badly sealed might need to be repaired or replaced to prevent penetrating damp from getting through.
- Porous bricks: Over time, bricks can become damaged which can lead to them becoming porous and allowing water to penetrate through.
What is the Difference Between Rising Damp and Penetrating Damp?
Understanding the two different types of damp is important for any homeowner. Rising damp is a type of damp that is usually caused by problems with the damp-proof course at your home. This is a waterproof layer designed to protect your foundation and internal walls from damp; however, if it is not working effectively, it could lead to moisture draining towards the home rather than away from it. Rising damp is different from penetrating damp mainly in how and where it will appear. While penetrating damp is likely to appear as localised patches on the walls where the water is making its way through, rising damp will happen on the ground floor only of the home, and is often just above the skirting boards. Sometimes it will rise to a certain height but will not usually go further and you don’t see it on the top floors of your home.
How to Solve Penetrating Damp
The first part in solving penetrating damp is to figure out how the moisture is getting into your home from the outside. A damp proofing professional can come to inspect your home and determine where the issues lie. They will perform a thorough inspection to find out which areas of your home are weaker and letting the water in, providing you with advice on how to rectify the problem and prevent further damp issues in the future. It’s important to make sure that you have found the cause of the penetrating damp and repaired it before you take any damp-proofing measures at home since, no matter how many damp-proofing strategies you take, penetrating damp will always come back regardless if you have not dealt with the root of the issue.
How to Stop Penetrating Damp
Locating the source of the moisture that is entering your home is the only way to stop penetrating damp. In most cases, this could be due to leaks coming in through cracks and holes in the external wall, or you might notice penetrating damp around windows and door if they have not been sealed properly or if the sealant is wearing away over time. Porous bricks that have not been treated with a damp-proof coating might be the cause of the damp if you cannot find any holes, cracks or sealant issues.
Guttering problems might also worsen penetrating damp problems by directing water towards, rather than away from the property after rainfall. Gutters and downspouts are designed to direct the water away from your property and its foundations. However, gutters that are clogged, broken, or leaking can send water straight to the house where it might find its way inside and lead to damp. If you suspect that your gutters might be playing a part in the penetrating damp issues that you are experiencing at home, it’s important to have them checked by a professional immediately. Sometimes all you will need is a professional gutter cleaning to see a huge difference.
How to Prevent Penetrating Damp?
Keeping your home well-maintained and in good repair is key to preventing penetrating damp in the future. Since poor maintenance is one of the most common causes of penetrating damp, it is important to make sure that you check your home regularly to ensure that there are no areas where the water could be getting through. Make sure to check your external walls for any signs of cracks, holes and other damage that could allow moisture to get inside the home, and check your roofing, doors, windows, and other fixtures too. You can also help to prevent penetrating damp from getting into your home through the bricks by treating your exterior brickwork with a damp-proof coating. This is usually best done during the summer to allow the brickwork time to dry. However, be careful when it comes to choosing the right damp-proofing treatment since you will want to choose one that allows moisture to escape from the inside wherever possible, to prevent issues with condensation damp at your home. Otherwise, you will need to make sure that your home is property ventilated and be mindful of any activities that you could take part in at home like cooking or washing clothes that might lead to additional moisture which will show up as condensation and then damp on the walls if the warm air has nowhere else to go.
Is Penetrating Damp Covered by Buildings Insurance?
Unfortunately, many home insurance companies fail to cover penetrating damp as an issue since the property defect that has led to penetrating damp occurring in the home might be considered to be general wear and tear. If you are in the process of getting buildings insurance and want to make sure that you are covered for penetrating damp problems in the future, carefully consider the policy that you opt for and make sure that you choose one that covers penetrating damp wherever possible. In some cases, for example, where the defect leading to the penetrating damp has been caused by a storm or other natural disaster, this might be covered by your home insurance. It’s a good idea to get in touch with your insurance company directly to find out about what is covered in terms of damp.
If the defects that are leading to penetrating damp inside of your property have been caused by poor maintenance or a lack of maintenance on the property, this will typically not be covered by your home insurance company in any circumstances since it is your responsibility to ensure that your property is maintained and kept in good condition. This might relate to defects with the roof or walls that have occurred as a result of aging and general wear and tear, which home insurance companies expect you to pay for maintenance for as the property owner. Around 10% of homeowners wrongly believe that they can use their home insurance policy to pay for fixing damp problems at home, so it’s important to double-check your policy and find out exactly what is and is not covered.
Understanding the signs, causes, and how to prevent penetrating damp will help you keep your home in the best condition.
Equipment Used During Our Surveys
Equipment Used During Our Surveys
Purpose:
Takes comparative moisture readings from walls, ceilings, floors and timber to identify abnormal moisture patterns.
Common Uses / Notes:
Used when investigating rising damp, penetrating damp, condensation and leaks. Readings support the survey but are not a diagnosis on their own.
Subsurface Moisture Meter
Purpose:
Detects moisture beneath the surface of suitable building materials.
Common Uses / Notes:
Helps determine whether moisture is confined to surface finishes or extends into the building fabric.
Non-Damaging Moisture Scanner
Purpose:
Scans surfaces for hidden moisture without causing damage.
Common Uses / Notes:
Ideal for decorated walls, ceilings and flooring where pin testing would be undesirable.
High-Resolution Borescope Camera
Purpose:
Inspects hidden or difficult-to-access areas without opening up large sections of the building.
Common Uses / Notes:
Used beneath floors, inside cavities, behind walls and around pipework to identify damp, leaks, decay and concealed defects.
4K Aerial Inspection Drone
Purpose:
Captures high-resolution images of roofs and other inaccessible external areas.
Common Uses / Notes:
Inspects roof coverings, chimneys, flashing, gutters, valleys, parapets and high-level masonry. Subject to weather, safety requirements and flight regulations.
Atmospheric Humidity Sensor
Purpose:
Measures indoor relative humidity levels.
Common Uses / Notes:
Helps assess condensation and mould risk alongside temperature, ventilation, heating patterns and room usage.
Gas Detection Monitor
Purpose:
Screens for certain airborne gases where unusual odours are present.
Common Uses / Notes:
May detect gases associated with drainage, combustion or flammable substances. Does not replace inspection by a Gas Safe registered engineer where gas appliances or pipework are involved.
Thermal Imaging System
Purpose:
Identifies temperature differences across building surfaces.
Common Uses / Notes:
Helps locate cold spots, thermal bridging, insulation defects and areas associated with concealed moisture. Results always require further investigation to confirm the cause.
Basic Socket and RCD Tester
Purpose:
Performs limited electrical checks during comprehensive surveys.
Common Uses / Notes:
Can identify basic socket wiring issues, AC voltage and RCD operation. It is not an Electrical Installation Condition Report (EICR).
Chemical Vapour Testing Device
Purpose:
Screens for airborne volatile organic compounds (VOCs) and formaldehyde.
Common Uses / Notes:
Used where chemical odours, emissions from materials or indoor air-quality concerns are suspected after leaks or refurbishment.
Fine Air Particle Counter
Purpose:
Measures airborne particulate matter (PM1.0, PM2.5 and PM10)
Common Uses / Notes:
Assists with investigations involving dust, smoke, mould concerns, post-construction contamination and indoor air quality following water damage.
Extraction and Air-Movement Tester
Purpose:
Measures the performance of extractor fans and mechanical ventilation systems.
Common Uses / Notes:
Used in kitchens, bathrooms and utility rooms to identify poor ventilation that may contribute to condensation and mould growth.
Survey Levels and Equipment Provided
Basic Moisture Survey
Standard price: £299 + VAT
Special offer: £199 + VAT until the end of this month
The Level 1 survey provides a basic assessment of the main accessible internal surfaces. It is most appropriate for simple, localised damp concerns where advanced testing is not required.
Equipment Included
- Professional damp meter
Survey Checks
- Accessible walls
- Accessible floors
- Ceilings
- Visible plumbing and drainage leak inspection
- Damp-control and prevention information
Suitable For
This survey is suitable for a customer who has found an isolated damp patch, suspects rising damp in a limited area or wants a straightforward check of the property’s accessible surfaces.
Only a standard damp meter is included. Customers requiring deep moisture detection, timber inspection, thermal imaging or roof inspection should select a higher survey level.
The survey fee will be deducted if we carry out the recommended work.
Damp, Moisture and Timber Survey
Standard price: £399 + VAT
Special offer: £299 + VAT until the end of this month
Level 2 includes everything in the Level 1 inspection and adds deeper moisture detection, non-invasive scanning and timber assessment.
Equipment Included
- Professional damp meter
- Deep-reading moisture meter
- Non-invasive moisture scanner
Survey Checks
- Accessible walls, floors and ceilings
- Visible plumbing and drainage leak checks
- Subsurface moisture readings
- Non-invasive scanning of appropriate materials
- Accessible underfloor and subfloor checks
- Wet rot inspection
- Dry rot inspection
- Woodworm inspection
- Damp prevention information
Suitable For
This level is intended for customers who require a more detailed inspection of dampness and timber condition. It is appropriate when moisture may be concealed within building materials or beneath accessible flooring.
The survey may identify evidence of timber decay or wood-boring insects and assess moisture in locations that cannot be properly examined with a surface meter alone.
Level 2 is particularly useful for homebuyers and sellers who want more information about damp and timber before completing a transaction.
The amount paid for the survey will be deducted from repairs undertaken by us.
Full Damp and Property Condition Survey
Standard price: £499 + VAT
Special offer: £399 + VAT until the end of this month
Level 3 is our most detailed inspection. It combines the checks from Levels 1 and 2 with advanced diagnostic technology, ventilation measurements and external roof-level assessment.
Equipment Included
- Professional damp meter
- Deep-reading moisture meter
- Non-invasive moisture scanner
- Thermal imaging camera
- Indoor humidity sensor
- HD borescope camera
- Airflow and ventilation tester
- 4K inspection drone
- Socket and RCD testing device
Survey Checks
- Accessible walls, floors and ceilings
- Visible plumbing and drainage
- Deep moisture investigation
- Non-destructive moisture scanning
- Accessible floor voids and subfloors
- Wet rot, dry rot and woodworm
- Infrared thermal imaging
- Indoor relative humidity
- Extractor-fan performance
- Borescope examination where suitable
- Visible damp-proof course
- External brickwork and pointing
- Roof coverings and junctions
- Chimney stacks and flashing
- Guttering and rainwater systems
- High-level exterior areas
- General visible structural condition
- Basic socket and RCD screening
- Drone photographs, subject to safe flying conditions
Suitable For
The Level 3 survey is recommended for buyers, sellers and existing owners who want the most extensive moisture assessment available.
It is especially useful for older properties, houses with several reported defects, basement buildings and cases involving damp, mould, leaks, poor ventilation, timber decay or roof problems.
The inspection considers the property as a connected building rather than examining only the visible damp patch. A roof or gutter defect, for example, may allow water to enter at a high level and appear some distance away internally.
The drone component provides valuable information about roofs, chimneys, parapets and guttering that cannot normally be seen from the ground. These areas may contain hidden repair costs capable of affecting a property purchase.
Identifying damage before buying can help the purchaser budget correctly, request further specialist advice or use the findings during negotiations. Even a relatively small roof defect may cost more to repair than the difference between the survey packages.
If we complete the recommended remedial work, your survey payment will be credited against the price.
Specialist Survey Add-On Services
For complex damp investigations, we offer three specialised laboratory and environmental testing add-ons:
Laboratory Analysis of Plaster Samples
Price £299 + VAT
Description: Small plaster samples are extracted from affected masonry walls and submitted to an independent testing laboratory. The lab analyses the sample for hygroscopic salts (specifically nitrates and chlorides).
Value: Scientifically differentiates true rising damp (which deposits ground salts over time) from surface condensation or lateral penetrating damp. Ensures that remedial recommendations are based on chemical analysis rather than surface meter readings alone.
This service can be beneficial when:
- The cause of low-level dampness is disputed.
- Moisture-meter readings are inconsistent.
- A property has undergone previous damp-proofing.
- Old plaster continues to attract moisture.
- Independent laboratory evidence is required.
- Several possible moisture sources are present.
Note: Salt analysis is only one part of the investigation. Results must be assessed alongside the location of moisture, condition of the masonry, external ground levels, damp-proof course and potential plumbing or rainwater defects. Requires minor invasive plaster sampling (the only add-on requiring material removal). Survey fee credited when repairs are completed by us.
Mould Identification & qPCR DNA Testing
Price £299 + VAT
Description: Surface swab samples are collected and sent to an accredited laboratory for advanced qPCR DNA analysis. Identifies exact mould species, measures spore concentrations and detects hidden fungal growth behind furniture, within void spaces, or under floorboards.
Value: Provides precise scientific data regarding mould toxicity and contamination levels, helping establish the exact scale of cleaning, drying and structural remediation needed.
Laboratory mould testing may be useful when:
- There is an unexplained musty odour.
- Visible mould repeatedly returns.
- Water damage occurred previously.
- Mould is suspected behind cupboards or furniture.
- Contamination may be present in a concealed location.
- The visible extent of growth is uncertain.
- Independent results are needed.
- Remediation work is being planned.
Note: The results can provide a clearer indication of whether contamination appears minor, concentrated or potentially widespread. This information may be used when deciding the scale of cleaning, removal, drying or remedial work required. Testing should be combined with an investigation of the moisture source. Removing visible mould without resolving the underlying condensation, leak or ventilation problem may allow it to return. Survey fee credited against subsequent remediation works completed by us.
Air Quality, Gas, Vapour & Airborne Particle Screening
Price £299 + VAT
Description: Comprehensive environmental air testing including:
- Indoor environmental quality – IAQ
- Volatile organic compounds – VOC and TVOC
- Formaldehyde – HCHO
- Fine airborne particles – PM1.0, PM2.5 and PM10
- Dust and smoke particles
- Sewer gases – H2S, NH3 and CH4
- Flammable gases – CH4 and C3H8
- Carbon monoxide – CO
- Hydrogen sulphide – H2S
- Ammonia – NH3
- Oxygen measurement – O2
- Ventilation and stale-air assessment
- Drain-smell investigation
- Chemical-odour investigation
- Air checks following a leak or flood
- Combustion-related screening
- Building-material off-gassing assessment
- General airborne pollutant monitoring
Value: Pinpoints invisible airborne hazards, toxic sewer gases, chemical off-gassing and foul odours resulting from damp or trapped water.
This service can assist when investigating:
- Persistent foul smells
- Suspected sewer or drain odours
- Chemical smells
- Stale indoor air
- Odours following water damage
- Possible stagnant water
- Building material emissions
- Fine dust after construction work
- Poorly ventilated rooms
Note: Unpleasant odours can have several possible sources. Measurements for specific gases, compounds and particles may help identify which source requires further investigation. The assessment is a screening service and does not replace specialist gas-safety, environmental or medical testing where this is necessary. Survey fee credited against subsequent repair works completed by us.
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: