PCA CERTIFIED
Penetrating Damp Treatment in London
At Dampstar, we provide professional penetrating damp services and treatments that focus on identifying the source of water ingress before recommending the most appropriate solution. Every property is different, so our approach is always tailored to the condition and construction of the building.
What is Penetrating Damp?
Penetrating damp develops when rainwater finds a route through the external fabric of a building. Cracked brickwork, deteriorated mortar joints, damaged render and defective roof coverings can all allow moisture to pass through and affect internal walls.
Over time, this can lead to damp patches, damaged plaster, peeling decoration and musty odours. If left unresolved, persistent moisture may also contribute to timber decay and further deterioration of the building fabric.
As similar symptoms can sometimes be caused by other forms of damp, a professional survey is the best way to establish the true cause before any repairs are carried out.
Signs Of Penetrating Damp
Penetrating damp isn’t limited to the lower part of a wall, unlike rising damp, and it often correlates with weather or a specific external defect, rather than sitting there constantly. It’s usually caused by something letting water in that shouldn’t, like a defect, a porous surface, or gap in the building’s structure.
Here’s what to look out for:
- Damp patches that don’t follow a height limit: unlike rising damp’s tide mark, these can appear anywhere on a wall, high or low, often directly linked to a specific fault point likecracked render or a damaged gutter.
- Patches that get worse after rain: if the damp seems to appear or spread noticeably during or after wet weather, that’s a strong indicator water is getting in from outside.
- Damp patches with defined edges: often a rounded or irregular shape, rather than the more even band you’d see with rising damp.
- Damaged or missing pointing, render, or brickwork: gaps in the external wall surface are common entry points for water.
- Blocked or leaking gutters and downpipes: overflowing water can run down the wall and soak in, especially near roof level.
- Cracked or missing roof tiles/flashing: a common cause where the damp shows up on upper floors or ceilings rather than at ground level.
- Mould growth in a specific, localised area: rather than spread evenly across a room, it tends to cluster near the point of entry.
How to Treat Penetrating Damp
Penetrating damp shouldn’t be covered up with a quick fix, as this only delays the problem and adds cost later. At Dampstar, we take a survey-led approach, so our treatment addresses the root cause rather than just the symptoms.
A thorough damp survey
Since penetrating damp is caused by a specific external defect, Dampstar’s survey focuses on tracing the exact entry point, whether that’s damaged brickwork, faulty guttering, or an issue with the roof. Getting this right is essential, as treating the wrong cause won’t solve the problem.
A detailed, no-obligation quotation
Once the source is identified, you’ll receive a clear, itemised quote outlining the repairs needed, at no extra cost. This gives you a full picture of the work and cost involved before anything begins.
Targeted repair of the underlying defect
Rather than just treating the symptom, such as redecorating over a damp patch, the repair addresses the actual entry point, whether that’s re-pointing brickwork, fixing guttering, or repairing damaged render or flashing. This stops the damp recurring.
Why Choose Dampstar?
As a trusted, expert local team, we combine traditional craftsmanship with modern methods, delivering reliable, on-time damp proofing results property owners can depend on.
Expertise
Our team has many years of hands-on experience dealing with all types of damp in London’s unique building landscape.
Honest assessments
We provide clear, transparent reports and never recommend work you don’t need.
Guaranteed work
Many of our services come with long-term guarantees for your peace of mind.
Full compliance
All our damp-proofing treatments are fully compliant with UK building regulations and industry standards.
Our excellent reputation
Our many 5 star Google reviews speak for themselves.
Trusted, PCA Certified Damp Proofing Services
Accreditations & Certifications
Our accreditations reflect our commitment to the highest standards in damp proofing, waterproofing and timber preservation. As PCA-certified damp and timber surveyors, we follow industry best practices, use proven methods and deliver work you can trust. Explore our professional accreditations and see why homeowners, landlords and commercial clients choose Dampstar.
What Our Clients Say
Damp Proofing in London Since 1960
Dampstar are based in Chiswick, West London, but provide penetrating damp treatment across the whole of London and Hertfordshire.
Our Services
Damp can lead to mould growth, damaged plaster, timber decay and poor indoor air quality if left untreated.
Groundwater soaking up into your walls ruins wallpaper, spoils plaster, and leaves musty smells.
Black Mould
Black mould causes toxic fungal growth on surfaces, causing breathing problems and allergic reactions.
Trapped steam from cooking and showering causes condensation on and around windows.
Moisture can lead to wet rot, dry rot and woodworm infestations, putting your property’s structural timber at risk.
Effective waterproofing protects your property from water ingress, damp, mould and costly structural damage.
Penetrating Damp FAQs
How do I know if it's penetrating damp and not another type of damp?
Penetrating damp can appear anywhere on a wall, often worsens after rain, and usually links to a specific defect. Our survey will confirm the exact cause.
Do I need a paid survey before getting a quote?
Yes, a paid survey identifies the source of the damp and is conducted by a PCA certified surveyor. If penetrating damp is found, Dampstar will provide a detailed quote for repairs at no extra cost.
What usually causes penetrating damp?
Common causes include damaged brickwork or render, blocked or leaking gutters, cracked roof tiles, or faulty flashing, anything that lets water in from outside.
How long does treatment take?
This depends on the cause and extent of the damage, but most repairs, such as re-pointing or guttering fixes, can be completed within a few days.
Will treatment involve a lot of disruption?
External repairs typically cause less disruption than internal work, though this depends on the specific defect being addressed. The team will always keep disruption to a minimum.
Can penetrating damp cause long-term damage if left untreated?
Yes, ongoing water ingress can damage plaster, timber, and brickwork over time, and may lead to mould growth or structural issues if not resolved.
Is penetrating damp covered by home insurance?
This varies by policy and provider, so it’s worth checking directly with your insurer, as this can depend on the specific cause of the damp.
How much does penetrating damp treatment cost?
Costs vary depending on the cause and extent of the repair needed. A survey is the best way to get an accurate, tailored quote.
Book A Survey
DAMPSTAR
Hours
- Mon 08:00 – 17:00
- Tue 08:00 – 17:00
- Wed 08:00 – 17:00
- Thu 08:00 – 17:00
- Fri 08:00 – 17:00
- Sat 09:00 – 17:00
- Sun Closed
