Greater London · London and the South East
Electronic leak detection in Northwood, Greater London
Electronic leak detection to pinpoint holes in flat roof membranes in Northwood, using drones and thermal imaging where it applies. Call or email for a price.
- Leaks through a flat roof with no obvious cause
- Stains far from any visible defect
- Leaks that return after repairs
Electronic leak detection in Northwood
Electronic leak detection, or ELD, finds holes in flat roof waterproofing membranes. It uses a small electrical current that passes through the membrane only where there is a breach. It can find holes too small to spot by eye, so your roofer can repair them. The results come in a report with photos. Typical surveys look at damage from equipment installers and water coming in under a flat roof, on roof terraces and balconies, commercial flat roofs and single-ply roofs.
Commercial and residential blocks across London often have big flat roofs with plant, rooflights and access walkways. Each pipe, upstand and fixing through the covering is a possible weak point. In Northwood, 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.
Nothing in the report is left vague: where something needs attention, it says so plainly.
- Place
- Northwood (HA6)
- Wider area
- Greater London
- Cost
- Quoted for your roof
- Your report
- Written, with photos, emailed to you
- Appointments
- Monday to Sunday, daytime
- Cover
- Professional indemnity and public liability
- Call
- 07833 053749
- Page updated
- 27 October 2026
FAQs for Northwood
Is parking a problem for a survey in Northwood?
It rarely stops a survey, but it is worth planning. Let us know what parking is available nearby, and the visit is planned around it.
Do you carry out roof surveys in Northwood?
Yes, Northwood is one of the places we work. The survey and report are the same in Northwood as anywhere else, and visits run on weekdays and weekends.
What do I do with the report?
We email you the written report with photographs and recommendations. It is yours to share with a seller, insurer, roofer or managing agent, whichever applies.
Do I need to be at home?
Not always. If we only need the outside, we can agree that beforehand, but the loft and any rooms with damp need someone to let us in.
How long will testing take?
It depends on the size of the roof and its build-up. You will know roughly how long before we start.
Will you fly a drone over my roof?
Yes, where it’s applicable. Our sub-250g drone is flown by a CAA-registered operator with a Flyer ID and Operator ID, and every flight depends on the airspace and the weather.
Do you carry professional indemnity insurance?
Professional indemnity and public liability insurance cover our surveys. If you need details for a managing agent or a building owner, just ask.
When you need someone else
To be straight with you, there are limits to any roof survey:
- Parts of the roof covered by fixed equipment
- Fixing the holes we find
- Some conductive membranes
Not sure which survey suits your roof? You can phone 07833 053749 or use the contact form and we will tell you. The full list of what we check.
What this survey covers
- Green roofs
- Liquid-applied waterproofing
- Single-ply roofs
- Flat roof membranes
- Roof terraces and balconies
- Commercial flat roofs
What you can safely check yourself
Look up at the roof after a storm, from ground level: pieces of tile or slate on the ground, a gap in the ridge or a lifted flashing are all worth noting. Leave anything above ground level to a survey.
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.
Do you need electronic leak detection in Northwood?
Joints and laps in a membrane can fail over time. Small openings at laps can leak long before anyone notices.
Problems we come across often include:
- Breaches hidden under paving or planting
- Failed seams and laps
- Holes around roof penetrations
- Patched roofs that still leak
For landlords with property near Carpenders Park station, a flat roof over a rented flat is easy to forget until the tenant reports a leak.
Choosing a roof surveyor
- Their insurance cover
- What experience they bring
- What the survey will not cover
- Do they have a CAA Flyer ID and Operator ID for drone work?
What we do, step by step
Where it’s relevant and can be reached safely, the roof space is checked as well as the outside. Inside, we look for staining, damp, gaps and signs of movement. All in, the survey normally takes longer on a large roof than a small one, with the construction of the roof playing a part too. Many London properties are flats or terraces with no side access, so the back of the roof is often seen from upstairs windows, from inside or, where a flight is allowed, from the air. Mention any building rules, key holders or managing agents when you book.
- You tell us about the roof and where water is showing.
- The roof is assessed for suitability first.
- We choose a low-voltage or high-voltage method to match the roof.
- We test the roof and locate any breaches.
- A report with photographs shows where each breach is.
Before the survey
- Tell us where we can park nearby
- Keep pets in another room
- Agree roof access with the managing agent if it is shared
How to book
You can call us seven days a week. For a price or to book, phone 07833 053749 or email us.
Related advice
Flat roofs in Northwood
Outer London has plenty of Victorian and Edwardian terraces with slate roofs, but also a great many interwar semis, frequently with hipped roofs in clay or concrete tiles. If your home in Northwood is one of them, bay roofs, hips and later dormers each have their own details. Mixed in with those pitched roofs are plenty of flat ones, over rear extensions, dormers, garages and shops. Historic houses like Headstone Manor, about 3.3 miles south-east, show how far back building in the area around Northwood goes. Older roofs in the wider area can hide decades of patch repairs, so the detail matters, and any change of roofing material on a listed home needs checking with the council first.
If you look after a building such as Frithwood 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 instance near Harlequin Centre, a flat roof over a business is out of sight and out of mind until it leaks.
Northwood is about 3 miles south-east of Rickmansworth, in Greater London. Roofs in Northwood get the same thorough look as anywhere else in Greater London. Our area takes in places right across Greater London, from the larger towns to small villages. Our London page covers surveys nearby.
All of HA6 is covered for electronic leak detection, from the main roads to the quietest streets. We cover properties on Little Stream Close and Sandy Lodge Way. Nearby, we also carry out electronic leak detection in Eastbury (1 mile north-east), Moor Park (1 mile north-west), Batchworth Heath (1 mile west), Batchworth (2 miles north-west) and Holywell (2 miles north). Within a short drive, we also cover City of Westminster (14 miles south-east), Marylebone (14 miles south-east), Kensington (12 miles south-east), St Pancras (14 miles south-east), Hampstead (11 miles south-east) and Ruislip (3 miles south).
Around Northwood
Around Northwood, our work takes us to homes and buildings near King George V Playing Fields, The Gate Public House and London School of Theology, among other places. The nearest railway station is Carpenders Park station, about 1.7 miles north-east of the centre. Well-known places in the area include Harlequin Centre (2.9 miles north-east) and Heath Robinson Museum (2.2 miles south-east). The countryside around Northwood includes Dews Farm Sand Pits and Tumbling Bay.
Leave it or get it looked at?
Water trapped under a membrane can soak insulation and decking. Locating it early helps limit the damage. In Northwood, as across London, an overflowing gutter soaks the wall below. A small blockage left for a few winters becomes a damp problem.
To find out what your survey will cost, call 07833 053749 or send us an email and let us know about the roof. We’ll confirm the figure before booking.
Why choose Independent Roof Survey in Northwood
- A photo-illustrated written report
- Surveys seven days a week
- Customer satisfaction of 98%
- An independent look at the roof
See our cost guide or two real surveys.
Tips that help
Here are a few things we’d tell any owner:
- Test new membranes before covering them
- Stay off the flat roof unless needed
- Act on new leaks promptly
- Keep outlets clear of debris
You receive a report showing where each breach was found, with photographs. Pass it to your roofer to repair the breach points.
Do not leave a flat roof leak running. Water under a membrane can spread.