Greater London · London and the South East
Electronic leak detection in Harlesden, Greater London
Electronic leak detection around Harlesden, with a written report you can act on. Weekday and weekend visits available.
- Patched roofs that still leak
- Leaks under green or ballasted roofs
- Breaches around outlets and penetrations
Electronic leak detection for homes and businesses in Harlesden
There are different ELD methods. Low-voltage testing is typically done with the surface wet, while high-voltage testing needs a dry, exposed membrane. The right method depends on the membrane and the build-up of the roof, and we’ll explain our choice. We’ll say if your roof doesn’t suit either method at the outset. Typical surveys look at punctures from foot traffic or tools and new membranes needing a check before handover, on single-ply roofs, green roofs and flat roof membranes.
Offices, shops and blocks of flats across London frequently have large flat roofs with plant, rooflights and walkways. Each pipe, upstand and fixing through the covering is a possible weak point. In Harlesden, roof access is agreed with the building manager or owner beforehand. Plant bases, rooflights and cable entries are all places where water can get in.
Where we cannot see part of the flat roof membrane, the report says so. You’ll know exactly what was inspected and what wasn’t.
- Place
- Harlesden (NW10, W3, NW26)
- Wider area
- Greater London
- Price
- Quoted for your roof
- Report
- Written, with photos, emailed to you
- Survey days
- Weekdays and weekends
- Insured
- PI and public liability insurance
- Call
- 07833 053749
- Updated
- 27 October 2026
What you can safely check yourself
You can learn a lot from the ground. With binoculars, look for slipped or missing slates and tiles, gaps along the ridge and leaning chimneys. Never climb onto the roof to look.
If you have a loft with safe access, take a look inside. Use a torch and stay on the joists or boards, checking for stains, damp wood or chinks of daylight.
Electronic leak detection in Harlesden: local notes
The wider area around Harlesden has a long history of building, with Pitzhanger Manor about 3.1 miles south-west. Period homes nearby can have lead valleys, tall chimneys and a patchwork of past repairs, and a listed home or one in a conservation area may need consent for changes of material. Alongside Victorian and Edwardian terraces, outer London has a great many interwar semis, often with hipped roofs of clay or concrete tiles. On a semi of that age, the small roofs over the bays, the hip tiles and any later dormer each need their own look. Next to the main roofs there is typically a flat roof somewhere, whether on an extension, a garage or a commercial unit.
If you look after a building such as John Keble CofE Primary School, large flat roofs, common on schools and other public buildings, need their outlets, upstands and coverings checked regularly. If you look after a shop, office or commercial unit, for example near London Designer Outlet, flat roofs over shops and units are easy to forget until water comes through a ceiling.
Harlesden is about 4 miles west of City of Westminster, in Greater London. Harlesden gets the same service as everywhere else we work: a careful inspection, photos and a written report. Across Greater London, we cover Harlesden and the places around it. We also survey roofs in London.
We work across the NW10, W3 and NW26 postcode area for electronic leak detection and the streets around it. Streets in the area include Fry Road, Wood Road and Park Road, all of which we cover. We also cover College Park (1 mile south-east), Old Oak Common (1 mile south), Church End (1 mile north), Stonebridge (1 mile north-west) and Willesden Green (1 mile north-east). We also work in nearby towns such as London (7 miles east), City of Westminster (4 miles east), Marylebone (5 miles east), Kensington (3 miles south-east), St Pancras (6 miles east) and Shoreditch (7 miles east).
Local landmarks in Harlesden
Locally, jobs take us to homes and businesses close to St Claudine's Catholic School for Girls, Royal Oak Inn and Roundwood Park. There’s a railway station in Harlesden itself: Willesden Junction station. Other landmarks nearby include Central Middlesex Hospital (1 mile west) and Brent Museum and Archives (1.1 miles north-east). For a walk, there’s Castlebar Hill and The Long Water.
Honest limits
Our survey is not a RICS Level 2 or Level 3 survey, a structural engineer’s report or an asbestos survey. It also has these limits:
- Carrying out the repair work
- Build-ups without a suitable layer below
- How wet the insulation is
Not sure which survey suits your roof? You can phone 07833 053749 or use the contact form and we’ll tell you before booking. What our survey covers.
What this survey covers
- Liquid-applied waterproofing
- Commercial flat roofs
- Flat roof membranes
- Single-ply roofs
- Green roofs
- Roof terraces and balconies
When to book a survey in Harlesden
When the membrane is buried, holes cannot be seen at all. ELD can work on some covered roofs, depending on the build-up.
Things that often lead to a survey include:
- Leaks through a flat roof with no obvious cause
- Gaps at membrane joints
- New roofs to check before paving or planting
- Punctures from foot traffic or tools
If you let a flat or house near Willesden Junction station, a flat roof over a rented flat is easy to forget until the tenant reports a leak.
Before booking any roof surveyor
- What the report includes, and whether it has photographs
- If they fly a drone, whether they hold a CAA Flyer ID and Operator ID
- Whether VAT is added on top
- How soon the report will arrive
Questions from Harlesden
Do you carry out roof surveys in Harlesden?
Yes, Harlesden is one of the places we work. The survey and report are the same in Harlesden as anywhere else, and visits run on weekdays and weekends.
Can parking be tricky for a visit in Harlesden?
Sometimes, yes. Where there are permit zones, a visitor permit or nearby pay-and-display bay works well.
Can you give me structural calculations?
No. We point out what can be seen, like sagging or deflection, but we are not structural engineers and do not carry out calculations. Where an engineer is needed, we say so in the report.
How experienced are you?
Over 5,000 surveys so far, across 20+ years of surveying roofs, with 98% customer satisfaction.
Is my roof suitable for ELD?
That depends on the roof’s membrane and layers. Let us know what you know about the roof and we’ll confirm suitability.
Can you test a green or ballasted roof?
On some roofs, yes. What sits on the membrane affects the method so we check the roof first.
Will you go up on the roof?
Not always. Safety comes first, and fragile or steep roofs can’t always be walked on. Safe viewpoints, the loft and a drone where it applies let us see the rest, and the report records anything we couldn’t see.
Towns and villages near Harlesden
Also in Harlesden
For landlords and managing agents
Buyers’ agents can book surveys on behalf of their clients. Reports are emailed, so they’re easy to pass on.
With a portfolio of properties, you can book surveys for several addresses. To arrange surveys for several addresses, ring 07833 053749 or send us an email with the addresses.
What affects the price in Harlesden
We confirm the price for your roof before you book. This is what makes a difference:
- The type of building, from a house to a block or an office
- Extensions, dormers and garages with roofs of their own
- Building height and the viewpoints available
- Features like valleys, chimneys, dormers and parapets
The cost of a survey depends on the roof: its size, its height, how many sections it has and how it can be reached and seen safely. Electronic leak detection is quoted for your roof, because the method depends on the roof.
What we need to know
There is no need for technical words. Just tell us:
- Your timetable, like an exchange date
- Where water is showing inside, if it is
- Why you want a survey: buying, a leak, a storm or new work
- Whether there’s a loft hatch, a shared roof or tricky access
Every survey is priced before it is booked, so you know where you stand. Electronic leak detection is quoted for your roof, because the method depends on the roof. To book, ring 07833 053749 or send us an email.
How the survey works
We look at the roof from outside and, where it’s relevant and there’s safe access, from inside the roof space too. In the loft, the signs we look for are staining, damp, daylight and sagging. All in, the survey typically takes more time on a big roof than a small one, with the construction of the roof playing a part too. From the street, a London terrace usually shows only its front slope or parapet, so a visit in Harlesden moves between viewpoints: the pavement, upstairs windows, the loft and any safe spot at the back. If other people live in the building, tell us who can let us into the shared parts.
- First, you let us know about the roof build-up and where water is showing.
- The roof is assessed to see if electronic testing will work on it.
- The testing method is chosen to suit the membrane and build-up.
- The roof is tested and any breaches are located.
- The breaches are recorded with photos in a report for your roofer.
Before we arrive
- Dig out any old roof reports or invoices
- Mention any parking restrictions on your street
- Keep pets inside or away from the areas we’re looking at
How to book
If you’re buying, it is useful to book soon after your offer is accepted, so there’s time to use the report before exchange. For any other survey, just ring 07833 053749 or email us when you are ready.