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South Harrow · HA2

Leak Detection in South Harrow

Non-destructive water leak detection across South Harrow, tracing hidden leaks with thermal imaging, acoustic sensors and tracer gas, then drying and treating the damage before it becomes mould.

★★★★★ 5.0 from 20 Google reviews · trusted by South Harrow homeowners, landlords & property managers

Last updated 19 September 2026

Quick answer: If you have a suspected water leak at a property in South Harrow, our specialists trace the source without tearing the place apart, using thermal, acoustic and tracer-gas methods. A leak is not over when the water stops. Mould can start within 48 hours, so we find the source, dry the structure and treat any mould, all with one company. Leak detection is a fixed £650, usually carried out within 3 to 5 working days. Urgent same-day or next-day leak detection adds £200 on a weekday, or £300 in the evening, on a Saturday or a Sunday, making it £850 or £950 in total. Call 020 3051 8478.

Leak to dry to treated, one company in South Harrow

South Harrow's housing stock is dominated by 1930s semi-detached and terraced houses built during the Metro-land expansion, many extended with flat-roofed rear kitchens and loft conversions, alongside interwar flats above the Northolt Road shopping parade. This mix of ageing roofs, retrofitted bathrooms and ad-hoc extensions creates multiple weak points where water can enter unnoticed for months.

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 →

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 →

Areas of South Harrow we cover

We attend leaks right across South Harrow and its neighbourhoods, including:

Common leaks in South Harrow homes

Flat-Roofed Rear Extensions

Many South Harrow semis along streets off Northolt Road and Alexandra Avenue gained flat-roofed kitchen or bathroom extensions during the 1960s and 1970s. Felt and asphalt coverings on these low-pitched roofs perish with age, and once the membrane splits, rainwater tracks along joists before showing as a ceiling stain. By the time damp appears indoors, insulation and timber below may already be saturated.

Bathrooms Above Shops and Ground-Floor Rooms

In the flats above the parades on Northolt Road and Alexandra Avenue, and in Roxeth and Rayners Lane houses with upstairs bathrooms added over kitchens, grouting and sealant around baths and showers dry out and crack. Water seeps through the floor rather than running visibly, so it can soak joists and the ceiling of the shop or room below for weeks before staining appears.

Ageing Plumbing in Original 1930s Pipework

Much of South Harrow's housing dates from the interwar Metro-land boom, and original supply pipes, soldered joints and stopcocks are now well beyond their intended lifespan. Hidden under solid ground floors or boxed into party walls between terraced houses, a failed joint or perished washer can release water for a long time before it surfaces, often travelling sideways to affect a neighbouring property first.

What our customers say

Excellent
Rated 5.0 / 5 based on 20 reviews on
Tip: If your water meter ticks over with every tap off, or a wall or ceiling stays damp with no obvious cause, there is a hidden leak. Finding it early is far cheaper than repairing the mould and damage it leaves behind.

Suspect a leak in South Harrow?

Call 020 3051 8478 or report a leak online. We trace, dry and treat for homeowners, landlords and managing agents across South Harrow.

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Frequently asked questions

How much does leak detection in South Harrow cost?
Leak detection is a fixed £650, usually carried out within 3 to 5 working days. Urgent same-day or next-day leak detection adds £200 on a weekday, or £300 in the evening, on a Saturday or a Sunday, making it £850 or £950 in total. You get a written, insurance-ready report identifying the source.
Will you damage my home finding the leak?
No. We use non-destructive thermal imaging, acoustic sensors and tracer gas to pinpoint the leak before any access is opened up, so repairs are targeted.
Do you fix the damage after finding the leak?
Yes. A leak is not over when the water stops. We dry the structure with monitored dehumidifiers and treat any mould, so it is handled end to end.
Do you provide reports for insurance claims?
Yes. Every leak investigation comes with a clear written report including the cause, photographic evidence and recommendations, formatted for insurers and managing agents.

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 →

Structural drying

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

Mould removal

Treat black mould in a South Harrow property and fix the moisture source behind it. Mould removal in South Harrow →