Penetrating Damp

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What is Penetrating Damp?

Penetrating damp is moisture that enters a building through the roof or external walls, which is different to rising damp, which comes from the ground. Years of driving rain can cause brickwork, masonry and render to decay and that can lead to moisture penetrating the material and causing damage to the internal walls and timber frames.

30 year warranty-badge

Leaking Roof

A major cause of penetrating damp is a leaking roof, which might be due to missing or dislodged roof tiles; another cause is blocked or damaged guttering that can lead to rainwater running down the external walls. Once rainwater enters the internal roof structure, it will damage joists and rafters and mould is likely to follow and if unaddressed, considerable damage will be the result.

Compromised External Walls

Whether brickwork, masonry or render, external surfaces have to endure the harsh British climate and that can lead to degeneration and moisture penetrates into the internal structure. You should closely inspect the external walls, looking for crumbling materials and moss growth, both of which are signs of moisture retention.

Timber Window & Door Frames

Timber frames are affixed to brickwork and usually have a mastic seal to prevent water from penetrating into the interior; this seal needs to be inspected on a regular basis and any breach should be repaired promptly. Check the interior window reveals for signs of damp and don’t forget to also look under the window board. 

Tell-Tale Signs of Penetrating Damp

Signs of penetrating damp include the following:

        • Damp patches on internal walls that remain damp
        • Damaged plaster and bubbling paint
        • Evidence of timber rot
        • Salt stains on walls
        • Rotting skirting and architrave
        • Mould and mildew on hard surfaces
        • Musky smell in the house
        • Moss growth on external walls

        If you should notice any of the above signs, you should contact London Damp Specialists and book an independent damp survey by a PCA-certified surveyor. This is the best way to get an accurate assessment of the damp issues in your property, plus you receive a free quote from the best damp-proofing company in London, an organisation that issues a 30-year guarantee on all their work.

        The Importance of Correct Diagnosis

        It is very easy to misdiagnose penetrating damp and that can lead to wasted money on ineffective repairs. Removing damaged plaster and recovering the affected area is not likely to be effective if the root cause of the damp is not addressed.

        How Best to Treat Penetrating Damp?

        Penetrating damp is a serious threat to London homes and with more than 40 years of hands-on experience treating damp and mould issues, we have all the solutions, which might include:

        • Cavity wall injectables
        • Waterproof renders
        • Water-repellent paints & coatings
        • Silicone sealants for roofing
        • Unblocking guttering
        • Sealing exterior walls in transparent coatings
        • Replacing damaged roof tiles

        The best treatment is determined after an inspection by a PCA-certified damp surveyor and we offer a free, no obligation quote along with a comprehensive 30-year guarantee on everything we do. Penetrating damp is a complex problem that might require numerous treatments to ensure that damp will not return. The problem is that penetrating damp is not normally apparent until considerable damage is caused, which is one good reason to have regular damp inspections that give you early detection.

        If the correct treatment is not carried out, the chances are that the damp will reappear and that means expensive and repeated repairs. Remedial work should not be undertaken until the root cause is established, only then can you move forward with some confidence.

        If you are planning to purchase a property in London and you are concerned about penetrating damp, we recommend booking our homebuyer damp survey, which is a thorough and detailed inspection that would reveal any damp, mould or timber rot issues.

        Many London homeowners are looking to check their home prior to the arrival of the cold winter months, which is the best time to undertake a professional damp survey.

        Call London Damp Specialists on 020 7458 4864 or complete the online booking form and let a PCA-certified surveyor inspect the property, looking for any signs of penetrating damp and other moisture issues.

Customer Testimonials

"Paul and Carlton did a very good job to insulate the loft. Carlton was very reliable, hard working with attentive to details. I would highly recommend the service"
Bill
"Paul was able to start work that week, and finished the job quickly, sticking to the price he quoted. Would definitely recommend."
Dan
"I hired Paul to re-plaster two internal walls due to a penetrating damp issue. He gave a competitive quote and clearly explained the work beforehand. … He performed the job with care and precision, kept me updated, and even worked alone while I was at work. … I have no problem recommending him to others."
Sebastian M
"Plasterer turned up on time and completed the job satisfactorily in two days. Work is now painted and looks great"
Nigel
"Excellent work from Paul and his team. Quote was fair and work was undertaken fairly soon. They protected the floors and tidied up afterwards with barely any sign of them having been in, impressive considering the scope of work done. It's now two months on and no signs of damp. Thanks Paul"
Mike D
"Paul was quick to respond with a team of proficient, friendly and professional workmen. The job was completed on time as promised. Great stuff. Thank you"
Tom
"As stated in previous reviews, work was carried out very professionally. Paul replied promptly, visited soon afterwards and gave great advice. … I was so impressed I didn't even bother to get other quotes! … Both rooms were spotless when they left. I would strongly recommend this company and wouldn’t hesitate to use them again."
Paula Symons
"Paul was polite, courteous and professional at all times. His work partner Alex came and completed the job. I've dealt with lots of building companies and builders and none have been as efficient, tidy and mindful of the clients surroundings as Alex was. He had a brilliant personality and his attention to detail was spot on. I would recommend Paul and Alex to anyone."
Geoff
"Paul gave a very competitive quote at a time that suited me. The 30-year guarantee is also a big plus! … He cleaned up thoroughly afterwards, and I’m very happy with the work. He even did a few extra jobs outside, which he didn’t have to. … I’d recommend using London Damp Proofing if you’ve got a damp problem!"
Cait Harvey
"Paul was very professional and friendly when he came to quote for a damp proof course and roof timber treatment for us."
Dan
"The work was carried out quickly and efficiently. Very impressed with reliability and work carried out. Talks through and explains all aspect of work before starting. Maintains contact throughout job. Would not hesitate to recommend."
Ebigail H
"Very professional service from Paul and his team. The quote was reasonable and fair. … His man turned up on time, did exactly what was explained, and left the area clean and tidy. … I would certainly recommend London Damp Specialists and use them again."
Adam
"Brilliant and professional job. Paul gave a quote and turned up on time with his assistant. … They paid attention to even the smallest details, and the work was completed to a very high standard. … If you're considering hiring Paul, just go ahead – it's very unlikely you'll be disappointed."
beagooner
"Super-efficient and speedy job and one of the team came back to do additional tidying up of the replaced skirting boards once it was finished."
Amy
"We had a number of large patches of damp… Paul was prompt to respond and quoted very quickly. His team was happy to work around a rewire, which really helped minimise disruption. … They applied damp treatment and even raised a couple of air bricks outside to stop rainwater coming in. I would very much recommend Paul and his team."
Jim Peacock
"Excellent work. We got London Damp Specialists to damp proof our basement. It was a pretty big job but they done it to a great standard and they where quick and clean. It has been months now since the work has been completed and its all painted and it looks fantastic and dry :) They are a great friendly bunch of lads. Thank you"
John S
"Efficient clean service. Came quickly to estimate and came when arranged to do the work."
Julia
"Paul was prompt and pleasant, and helpful in assessing where we needed damp proof course installed. A good, neat job over the course of two days."
Karl
"Very happy with the job, straightforward, would highly recommend."
Lauren
"Really pleased with Paul's work. Fabulous work done, hopefully damp won't return. Honest and efficient."
Mark
"What an absolutely stunning job! … I left for work with an incredibly uneven, cracking, poor attempt at damp proofing my kitchen. I returned to find Paul had already left… and the kitchen walls… well, wow, wow, wow. … Completely re-plastered, now straight, totally even and as smooth as ice. … If you want a truly professional, platinum grade job done at a very reasonable price, hire Paul – you will not be disappointed."
Sarah J
"Clean and tidy, very polite, job done. Very flexible to come and quote at weekend and work conducted very quickly. No complaints! Thanks Paul!"
Vera
FAQs
Can a new build fall victim to damp and mould?

Yes, any structure can be damaged by rising damp, mould, penetrating damp, condensation, although the older the house, the more likely damp will be present. If damp is present in a new house, you should contact the builder, as you should be covered by their warranty.

Can wallpaper and paint hide damp issues?

Yes, wallpaper and paint can temporarily conceal damp issues, but they worsen over time and promote mould growth. They don’t address the underlying problem of moisture. It’s crucial to identify and fix the source of dampness for long-term solutions.

Do I have to pay a deposit for damp proofing services?

We do not require payment until the work is dry and you are satisfied with the service.

In what format is the survey report that is issued to me?

We usually prepare a paper copy, plus the report is emailed to the customer and this usually happens within 24 hours. If you suspect that your home has damp issues, call us on 020 7458 4864 or fill in the form on our website.

What are the different forms of damp?

There are two main types of damp, namely rising damp and penetrating damp and the difference is that rising damp comes from the ground, while penetrating damp can enter a building at any location.

Would the damp proofing team explain the process?

Of course, the foreman would give you a clear understanding of the work to be carried out, plus he would be happy to answer any questions you may have. If you are interested, they would impart their knowledge, helping you to gain a deeper understanding of what is being done, plus they can give you a few tips to prevent condensation.

Still have a question?
Get in Touch

Our 5 Step Process

01

Initial Consultation

Tell us about your damp issue and we’ll guide you on next steps. It's an opportunity for you to ask questions and gather information.

02

Site Visit

Next, we visit your property to find the root cause of the issue. We’ll also assess the local environment, and take measurements or observations.

03

No Obligation Quote

Then we’ll send a detailed estimate of the costs involved, with no hidden extras, and provided to you without any commitment. You can review the financial aspect before making any decisions.

04

Work Carried Out

Our expert team carries out the work as planned, to the agreed timeline and quality standards, with minimum disruption to you.

05

Payment

The last step is payment, once the work’s complete, your home is dry and you’re satisfied with the results.

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