City of London · London and the South East
Electronic leak detection in City of London
Electronic leak detection around City of London, with a written report you can act on. Weekday and weekend visits available.
- Gaps at membrane joints
- Leaks showing away from the breach
- Repairs that haven’t stopped the leak
What happens on the day
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, as far as the space allows. The whole visit usually takes a length of time set by the size of the roof and how it’s built, and we’ll give you a guide when quoting. From the street, a London terrace typically shows only its front slope or parapet, so in City of London we work round the house, using the street, the windows, the loft and any safe vantage point behind it. If other people live in the building, let us know who can let us into the shared parts.
- We start with what you know about the roof and the leak.
- The roof is assessed for suitability first.
- The test method is chosen to suit the roof.
- The membrane is tested and breaches are found.
- You get a report with photos of each breach.
Before we arrive
- Clear the way to the loft hatch
- Tell us about any leaks, stains or damp patches you know of
- For flats, make sure roof access has been agreed
Booking a survey
To arrange a survey, call 07833 053749 or use the contact form and tell us the address and what’s prompted the survey. We’ll confirm the price before you book.
Related advice
Electronic leak detection for homes and businesses in City of London
ELD is a way of pinpointing breaches in a flat roof’s waterproofing membrane. It uses a small electrical current which can only get through the membrane at a breach. That lets us locate holes that are too small to see, so your roofer can repair them. You get a report with photographs of each breach found. We survey commercial flat roofs, single-ply roofs and flat roof membranes, and common reasons people get in touch are leaks that return after repairs and water coming in under a flat roof.
Commercial and residential blocks across London often have big flat roofs with plant, rooflights and access walkways. Every penetration and upstand is a place where a membrane can fail. In City of London, 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.
The report works through the roof section by section, from the main slopes down to the gutters and outlets. You’ll see the good as well as the bad.
- Place
- City of London (EC4V, EC1A, EC2M, EC2Y)
- Wider area
- City of London
- Prices
- Quoted for your roof
- Report
- A written report with photos, by email
- When we survey
- Weekdays and weekends
- Insurance
- PI and public liability insurance
- Call
- 07833 053749
- Last updated
- 27 October 2026
Why act early in City of London
Opening up a roof to hunt for a leak is disruptive. ELD aims to locate the breach first, so the repair can be targeted. In a London terrace or conversion, a roof defect rarely stays your problem alone: failed flashings and blocked valley gutters can send water into more than one home. Finding it early keeps the work smaller.
What a survey costs comes down to the roof itself: how big it is, how high it is, the number of separate roofs and how it can be reached and seen safely. Electronic leak detection is quoted for your roof, because the method depends on the roof.
Why us?
- An independent view of the roof
- We hold a CAA Flyer ID and Operator ID
- Over 20 years’ experience
- Thermal imaging and drones used where they help
Read our cost guide and two real surveys.
Towns and villages near City of London
More services for City of London
Landlords, agents and block managers in City of London
We survey roofs for landlords and agents as well as homeowners. A written report with photos gives you a clear record of the flat roof membrane.
An agent can book and manage the survey for a landlord, and the report can go to both. We agree a time with the tenant beforehand.
Practical tips
Getting the most from electronic leak detection starts before we arrive and carries on afterwards. Some tips:
- Don’t let outlets block
- Ask contractors to protect the membrane
- Note where leaks show inside and when
- Do not leave water getting in
Once repairs are made, the roof can be tested again if you want to check them if the build-up allows.
Limit foot traffic on flat roofs. Many breaches come from foot traffic.
What this survey cannot tell you
This is not a RICS building survey, a structural engineer’s report or an asbestos survey. Other limits to bear in mind:
- Sections we can’t safely access
- Build-ups without a suitable layer below
- Fixing the holes we find
If you’re not sure which survey you need, phone 07833 053749 or use the contact form and we will give you a straight answer. The full list of what we check.
Roof types and parts we check
- Commercial flat roofs
- Roof terraces and balconies
- Green roofs
- Single-ply roofs
- Flat roof membranes
- Liquid-applied waterproofing
What we look for on each type of roof
Liquid-applied waterproofing
What lies under a liquid coating decides if ELD will work.
Green and ballasted roofs
Some layers may need lifting for testing. We discuss this before quoting.
City of London: your questions answered
Does a conservation area affect roof work in City of London?
For listing, use Historic England’s list; for conservation areas, ask the council. It matters most if you are planning to re-roof in a different material.
Do you look at commercial flat roofs near City of London, such as hotels?
Yes, commercial buildings, hotels included, are part of the work. Access to the roof is sorted out with whoever manages the building before the day.
What if it rains on the day?
Light rain is usually fine; heavy rain and wind are different. In strong wind or a downpour, a drone cannot fly and access may not be safe, so we’d move the date with you.
How soon will I get the report?
Basic reports arrive within 48 hours, Standard reports in 24–48 hours and Premium reports on the same day. All of them come by email.
Do you use drones?
Yes, where it is applicable. We hold a CAA Flyer ID and Operator ID and fly a drone under 250g, and the airspace and weather are checked before every flight.
I live in a flat. Can you survey the roof?
Yes. Shared roofs just need a little more planning. Mention it when you get in touch and we’ll explain what’s needed.
What is electronic leak detection?
ELD passes a small electrical current across the roof to locate holes in the membrane. A breach lets the current through, which shows us where the hole is.
Electronic leak detection around City of London
Historic houses like Mansion House, about 0.2 miles south-east, show how far back building in the area around City of London goes. Older homes in the wider area often have features worth a closer look, such as lead valleys, tall stacks and roofs that have been patched over the years, and any change of roofing material on a listed home needs checking with the council first. Within a mile and a half or so of City of London there are several hotels, and like offices and blocks, hotels often sit under flat roofs. For hotels and other commercial buildings, finding the cause of a flat roof leak quickly keeps rooms in use.
For site and facilities teams at buildings such as Fashion Retail Academy, 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 Gabriel's Wharf, flat roofs over shops and units are easy to forget until water comes through a ceiling. Hotels and guest houses near City of London cannot easily close rooms for a leak, so it is worth knowing the roof’s condition.
City of London is about 1 mile north of London. Wherever you are in City of London, we can carry out electronic leak detection at your property.
We survey roofs across EC4V, EC1A, EC2M and EC2Y for electronic leak detection and the streets around it. We offer electronic leak detection to properties on Aldermanbury Square, Monkwell Square and Paternoster Square. Main roads around City of London include the A1 and A3, so getting to you is simple. Neighbouring places we cover for electronic leak detection include Barbican Estate (1 mile north), Bishopsgate (1 mile east), Finsbury (1 mile north), Aldgate (1 mile east) and St Luke's (1 mile north).
What’s near City of London
Typical jobs here are in homes near St Mary-at-Hill, Prior Weston Primary School and Children's Centre and Golden Fleece pub and the streets around them. Nearby too are Central Foundation Boys' School (0.8 miles north), Barts Health Archives (less than half a mile north-west) and St Alphage Garden (under half a mile north). There’s a railway station in City of London itself: London Cannon Street station. Nearby you’ll also find Gabriel's Wharf (0.8 miles south-west) and London Mithraeum (under half a mile south). Green spaces nearby include St. James's Park Lake and Barnsbury Wood.