Services / Damp Proofing / Interstitial Condensation
Interstitial condensation treatment in London & surrounding counties
We find where moisture is trapped in the building and treat it, then hand the property back redecorated, with a 20-year company guarantee.
- Damp patches that keep coming back
- Damp on a blocked-off chimney breast
- Staining or peeling paint
- Blown plaster
- Damp with no obvious source
Signs of interstitial condensation
Interstitial condensation occurs when moisture becomes trapped within the building fabric, causing recurring damp patches, staining, peeling paint or blown plaster. Our experienced surveyors are skilled at identifying difficult damp issues and their underlying causes.
You may have interstitial condensation if:
Damp patches or staining keep coming back, even after redecorating.
A blocked-off chimney breast is damp or stained.
Paint is peeling or the plaster has blown, with no obvious leak.
Treatment for interstitial condensation
Treatment depends on the cause and construction of the building. We identify and remove the source of moisture, then use the most appropriate remedial system, which may include removing unsuitable materials, improving ventilation, repairing external defects or installing a suitable waterproofing system.
How a damp repair works
01Instant estimate
Measure the affected walls and ceilings, and our estimate tool gives you an indicative cost in under a minute, with no contact details required.
02Survey and written diagnosis
We carry out a thorough damp survey, using specialist diagnostic equipment and many years of experience to identify the underlying cause and provide a clear written diagnosis with recommended remedial works.
03Treat the damp
We treat the underlying cause of the damp, using the appropriate remedial system for the property. This may include removing damaged materials, installing damp-proof barriers or waterproof membranes, and repairing external defects causing water ingress.
Our team also specialises in lime pointing and lime plastering, particularly where traditional materials are appropriate for the building.
04Decorate and hand back
Unlike traditional damp-proofing systems, our remedial works mean affected areas are ready to decorate 30 minutes after the repair, with no need to wait 4–6 weeks. We complete the full reinstatement, including decoration, skirting and joinery, getting your property back into use in a fraction of the time, with one company managing the entire process from start to finish.
All remedial works are backed by our 20-year company guarantee.
Cost of interstitial condensation treatment
Our prices are based on the m² of damp-proofing required. Where lime work is required, the cost will be similar.
Use our free estimating tool to get an instant, reasonably accurate estimate. If you’re happy with the price, you can book one of our surveyors to visit and provide a detailed quotation.
Prefer to speak to someone? Contact us to arrange a survey directly.
Why use Perlini for damp proofing
Damp proofing guarantee
We provide a 20-year company guarantee on damp-proofing works, with insurance-backed guarantees available for added protection. All remedial works also include a 1-year workmanship guarantee.
No drying period
If you’re in a rush, small jobs can often be completed within one day and are ready to decorate 30 minutes after the repair. Larger projects are also completed quickly, with our system avoiding the 4–6 week drying period often associated with traditional damp-proofing methods.
Survey
We survey the property, identifying the cause of the damp and putting our findings in writing. We then recommend the most appropriate solution for the building, ensuring the proposed works address the underlying problem rather than simply treating the symptoms.
Itemised quotation
The report includes a fully itemised quotation for the required repairs, so you get clear, transparent pricing.
End-to-end repair service
Our experienced team can manage every aspect of your project in-house, with no need for subcontractors or multiple companies. From damp-proofing and remedial works to plastering, lime work, repairs and decoration, we manage everything under one roof, so you get consistent standards and clear accountability from investigation through to completion.
Accredited & trusted
CHAS accredited, Constructionline Gold member, expert installer of Safeguard products, Biokil approved contractor and multi-award-winning service provider.
What clients say
"Top quality damp correction experts well versed in traditional and proven techniques of damp diagnosis, correction and prevention. Highly skilled team taking pride in their work. Work is of the highest quality and always in sympathy with the building. Quote process transparent and comprehensive. Highly recommended."
J H
"I highly recommend Rosco & Perlini. A friend introduced me to this company and I couldn't be happier. Not only was the damp dealt with, but the standard of work was excellent. The team was very professional and informative. My house was left looking clean, tidy and dry."
James Barber
"Really impressed with this company and would definitely recommend. Everyone we met was friendly and polite. Communication was clear and prompt throughout. The causes of our damp issues were identified and the work to remedy them carried out to a high standard. Timescales were realistic and kept to. A good experience from beginning to end and will be using them again should the need arise."
Tom Stacey
Frequently asked questions
Questions about interstitial condensation.
Other damp proofing services
Condensation and mould
Condensation occurs when warm, moisture-laden air meets colder surfaces, creating conditions where mould can develop. We identify the underlying cause and recommend practical measures to control moisture, improve ventilation and prevent recurrence.
Lateral damp
Lateral damp occurs when moisture penetrates horizontally through walls, commonly where a building is below ground level or where external ground levels are higher than the internal floor level.
Penetrating damp
Penetrating damp occurs when water enters a building from outside, often through defective roofs, walls, gutters, pointing, windows or other external elements. We identify the source of water ingress and recommend the appropriate repairs to resolve the underlying issue.