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Harrow on the Hill · HA1, HA2

Damp, Mould & Leak Specialists in Harrow on the Hill

Non-destructive damp surveys, hidden leak detection and mould investigation across Harrow on the Hill and the surrounding area, with clear, insurance-ready reports.

Call 020 3051 8478Request a survey
★★★★★ 5.0 from 20 Google reviews · trusted by Harrow on the Hill homeowners, landlords & property managers
Quick answer: If you have damp, mould or a suspected water leak at a property in Harrow on the Hill, our specialists carry out a non-destructive survey to find the root cause, then give you a written report and a clear plan to fix it. A full damp and mould survey is a fixed £500. Call 020 3051 8478.
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Damp, mould & leak services in Harrow on the Hill

Harrow on the Hill's housing stock is dominated by Georgian and Victorian villas within its conservation area, many tied to Harrow School's estate, alongside Edwardian terraces and 1930s mock-Tudor semis lower down the hill. Solid brick walls, ageing slate roofs and single-glazed sash windows are common, and the hill's clay subsoil and steep gradients make these older properties prone to penetrating damp, rising damp and drainage-related leaks.

Leak Detection

Trace hidden water leaks without damage using thermal, acoustic and tracer-gas methods. Leak detection →

Damp Investigation

Identify rising damp, penetrating damp and condensation, and tell them apart properly. Damp investigation →

Mould Inspection

Find the moisture source feeding the mould, not just treat the surface. Mould inspection →

Structural Drying

Dry out walls, floors and voids after a leak or flood, monitored to completion. Structural drying →

Areas of Harrow on the Hill we cover

We survey properties right across Harrow on the Hill and its neighbourhoods, including:

Common damp problems in Harrow on the Hill homes

Solid Wall Damp in the Conservation Area's Georgian and Victorian Villas

Many properties around the historic hilltop and Church Hill have solid brick walls with no cavity, built before damp-proof courses were standard. Original lime render has often been replaced with modern cement render, trapping moisture inside the walls. This causes rising damp at skirting level and damp patches on chimney breasts, particularly in ground-floor rooms facing the prevailing wind on the exposed hilltop.

Roof and Guttering Leaks on Steeply Pitched Slate Roofs

The steep slate and clay-tile roofs typical of Harrow on the Hill's older villas and school-adjacent buildings are prone to slipped or cracked tiles after storms, especially given the hill's exposure. Ageing cast-iron guttering and hidden valley gutters on Victorian additions frequently overflow or corrode, sending water down into loft insulation and ceiling voids, leading to mould blooms in bedrooms below and stained plasterwork.

Condensation and Mould in Converted Flats and Basement Rooms

Around Sudbury Hill, Roxeth and West Harrow, many larger Victorian and Edwardian houses have been split into flats with poor ventilation and shared, often blocked, airbricks. Basement and semi-basement conversions near the lower slopes suffer from lateral damp pushing through solid retaining walls, while draught-proofing added to sash windows upstairs traps humid air, producing black mould around window reveals and in bathrooms lacking extraction.

What our customers say

Excellent
Rated 5.0 / 5 based on 20 reviews on

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!

Mariama✓ a month ago

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…

Susan Bessim✓ 2 months ago

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!

Patryk Gutowski✓ 2 months ago

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.

Keiryn Raf✓ 3 months ago

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. :)

Joeie Rouse✓ 5 months ago
See all reviews on Google
Tip: If a damp patch keeps coming back after redecorating, it is almost always a symptom, not the problem. A survey that finds the source first saves paying for the same repair twice.

Book a survey in Harrow on the Hill

Call 020 3051 8478 or request a survey online. We work with homeowners, landlords and property managers across Harrow on the Hill. Works are on a 50% upfront, 50% on completion basis.

Frequently asked questions

How much does a damp survey in Harrow on the Hill cost?
A damp and mould survey is a fixed £500, including the non-destructive investigation and an insurance-ready written report. Leak detection, if needed, is £800 to £1500 depending on scale.
Do you cover the whole of Harrow on the Hill?
Yes. We survey properties across Harrow on the Hill and the surrounding neighbourhoods and postcodes.
Can you tell the difference between condensation, rising and penetrating damp?
Yes, and it matters because the fix differs for each. Our survey identifies which type you have using moisture readings and thermal imaging.
Do you provide reports for insurance claims?
Yes. Every survey comes with a clear written report including the cause, photographic evidence and recommendations, formatted for insurers and managing agents.