Last updated 19 September 2026
Leak to dry to treated, one company in South Harrow
South Harrow is dominated by 1930s bay-fronted semis and terraces around Northolt Road and Alexandra Avenue, alongside interwar flats near the Piccadilly line station. Solid or early cavity brick walls, boxed-in original chimneys and loft conversions with limited ventilation make these homes prone to trapped moisture, especially where uPVC replacement windows have sealed out the draughts older properties once relied on.
Mould Treatment
Treat and prevent the mould that follows water damage, dealing with the moisture source first. Mould treatment →
Damp Investigation
Tell rising damp, penetrating damp and condensation apart, so the right repair is done once. Damp investigation →
Leak Detection
Trace hidden water leaks without unnecessary damage using thermal, acoustic and tracer-gas methods. Leak detection →
Structural Drying
Dry walls, floors and voids after a leak or flood with monitored dehumidifiers, to completion. Structural drying →
Areas of South Harrow we cover
We treat mould right across South Harrow and its neighbourhoods, including:
- Rayners Lane
- Sudbury Hill
- Roxeth
- West Harrow
- Harrow-on-the-Hill
- Harrow
- Northolt
Common causes of mould in South Harrow homes
Solid-wall semis and cold bridging
Many South Harrow semis on roads off Northolt Road and Alexandra Avenue were built with solid or poorly insulated cavity walls, so internal surfaces stay cold relative to room air. This encourages condensation and black mould on external walls, particularly in corner bedrooms and behind wardrobes pushed against outside walls, where airflow is restricted and moisture has nowhere to escape.
Converted flats with shared bathrooms and lofts
The area's Victorian and 1930s houses split into flats near South Harrow station often have bathrooms without working extractor fans and lofts converted without adequate breathing membranes. Steam from showers lingers in poorly ventilated en-suites and box rooms, feeding mould growth on ceilings and around window reveals, while shared pipework leaks between flats can introduce hidden penetrating damp.
Sealed uPVC windows trapping moisture
Replacement uPVC windows fitted to original 1930s frames across South Harrow have cut natural draughts that once dried out rooms, but many lack trickle vents. Bedrooms and bathrooms in these homes now hold more airborne moisture, producing black speckling on window reveals, sills and surrounding plaster, and mould creeping behind curtains and furniture placed close to the glass.
What our customers say
Friendly, approachable and most importantly professional. Great service!!
spoke with Karim who was incredibly knowledgable and helpful. He provided me with very useful information and went out of his way to help me. He also answered all my questions thoroughly. They were very fast to respond via email and wotsapp
Clearly communication, easy to deal with and responsive. We would thoroughly recommend. The report was really detailed making our buying negotiations a lot stronger and leaving us with a clear plan of action with possible timeframes.
Was lovely working with the team and they did a fantastic and quick job to get all the mould out of my bathroom. Very much looking forward to working with them on other projects around my house!! Thank you for everything and shout out to Karim for being so sweet!
Top notch customer service from Kerim! He fully explained the process properly so we knew the ins and outs of the cost and the plan of action. The survey was done, they treated the mould and followed it up with a dehumidifier session and that's it no more mould, no more dampness and best of all no over complicated jargon and inflated prices. I left it a month before leaving this review to see if the mould would come back and I have had zero issues. I would highly recommend Damp & Mould Solutions UK.
Omg what brilliant service, excellent the cleaner did a very good job was efficient he took his time and cleaned everything, highly recommend S. Bessim…
Fast and efficient service
Highly recommend this company, very professional but kind service provided.
Very positive experience. From the first call every detail of the process was explained clearly which put me at ease. Kerim shared knowledge of what I should expect from the survey, and what to expect from the treatment so I could plan my day accordingly. I was provided a quote the same day which was the most competitive of all the quotes I received. Easy to book, friendly to talk with and completely took away all my stress. If you're dealing with mould and in a similar situation as I was, these guys are definitely worth the call.
Kerim and his team were amazing! Firstly, they surveyed my home and the report they provided was very detailed and found the cause to be a leak from the bathroom. As it was an active leak we were quoted the same day and had his team over the next day to fix the leak. Once the leak was fixed they returned the following week to install drying units and treat the mould. They returned 2 weeks later to collect their machines and provided us with a certificate of dryness which proved it was all dry and fixed. All in all the whole process was efficient and I couldn't fault their service in the slightest. Within a month our home is back to feeling clean and stress free. We are glad to have found someone we can trust and we will definitely keep your number saved and we will be recommending you to all of our friends and family.
Amazing company! They responding very quickly. They have a low prices as well, not crazy quotes like from others. Job has been done very quickly and team was very professional. I will use them in the future if I needed. Thanks!
Really impressed with the whole experience. The surveyor did a proper, thorough job and didn't rush anything, they got to the root cause of the damp and explained it all clearly. Detailed, professional and reassuring from start to finish. Couldn't recommend them more highly.
We used Damp & Mould Solutions to check whether damp in our living room and bedroom was being caused by structural issues with our leasehold block or simply poor insulation/ventilation. The service was very impressive, with our surveyor David explaining the issues and best solutions clearly to my partner and I. The final report produced was professional and reassuring, meaning we don’t have to take a case to the council. Overall, fantastic service and would certainly use again!
Great experience with this company from start to finish. They were professional, knowledgeable, and explained everything clearly without any pressure. The work was carried out efficiently and to a high standard, and we’ve already noticed a big improvement. It’s reassuring to deal with a team that genuinely cares about doing the job properly. Highly recommend to anyone dealing with damp or mould issues.
Very professional and organised I must say came out and completed the work very efficiently customer service was excellent. Definitely recommend this damp and mould service to anyone looking for a job done correctly. :)
I have been dealing with damp and mould for years but these guys were able to come in and resolve the problem quickly and professionally. Their prices were fair and reasonable and they got the job done clean. 10/10 would use again and would recommend.
Used Damp & Mould Solutions UK for a damp and mould issue at my property in South London. Really professional service, fast response and very knowledgeable. They use specialist equipment including thermal imaging which gave us a clear diagnosis. Would highly recommend to anyone dealing with damp, mould or a hidden leak.
Very helpful and professional, easy to communicate with about my mould issues and I received fast responses from the company on the best solutions for me. would recommend to all friends and family. 5/5
I recently used a damp and mould specialist company and was extremely impressed with the service from start to finish. From the initial survey, they were knowledgeable, thorough, and took the time to clearly explain the cause of the issue rather than just treating the symptoms.
Mould problem in South Harrow?
Call 020 3051 8478 or book a mould survey online. We remove mould and fix the cause for homeowners, landlords and managing agents across South Harrow.
Frequently asked questions
How much does mould removal in South Harrow cost?
Is black mould in my home dangerous?
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More help in South Harrow
Damp and mould survey
Find the real cause of damp, mould or a leak in a South Harrow property, with a written report and photographs. Damp survey in South Harrow →
Leak detection
Trace a hidden water leak in South Harrow using thermal, acoustic and tracer gas methods, with minimal damage. Leak detection in South Harrow →
Structural drying
Dry walls, floors and voids in South Harrow after a leak or flood, monitored to completion. Structural drying in South Harrow →