Greater London · London and the South East
Electronic leak detection in Hornsey, Greater London
Wondering about the flat roof membrane at a property in Hornsey? We carry out electronic leak detection in Hornsey and across Greater London, with plain-English findings.
- Leaking laps in the waterproofing
- Leaks at pipes, outlets or fixings
- Waterproofing to test before it’s covered
What a survey costs
To price your survey, we check:
- The type of building, from a house to a block or an office
- How tall the building is and how easy the roof is to see
- Chimneys, valleys, parapets and other details
- How many separate roofs there are, such as extensions, dormers and garages
To find out what your survey will cost, ring 07833 053749 or send us an email and tell us about the roof. The price is agreed before a date is set.
What to tell us when you contact us
Here’s what helps us most when you get in touch:
- Any marks or damp showing indoors
- The style of property, from a terrace to a block
- When you need the report by
- The reason for the survey, like buying, a leak or storm damage
Getting a price is simple: just call 07833 053749 or use the contact form and give us some details about the property and we’ll suggest the right survey. We confirm the price before anything is booked.
Electronic leak detection for homes and businesses in Hornsey
There are different ELD methods. Low-voltage testing is usually done with the surface wet and high-voltage methods need the membrane dry and exposed. Which one suits depends on the membrane and the layers of the roof, and we will explain our choice. If neither method suits your roof, we’ll tell you before any testing starts. We are often asked to look into damp inside with no sign on the roof and breaches hidden under paving or planting, across roof terraces and balconies, commercial flat roofs and single-ply roofs.
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 Hornsey, roof access is agreed with the building manager or owner beforehand. Rooflights, plant supports and pipe entries are common places for a membrane to fail.
Most points in the report come with a picture, so you can see each defect rather than just read about it. Anything out of sight on the day is listed as such.
- Place
- Hornsey (N8, N22)
- Wider area
- Greater London
- Prices
- Quoted for your roof
- Report
- Emailed report with photos and recommendations
- When we survey
- Weekdays and weekends
- Cover
- Professional indemnity and public liability
- Call
- 07833 053749
- Last updated
- 27 October 2026
Different roofs, different checks
Liquid-applied waterproofing
Small holes in liquid waterproofing may leak. Where the roof suits it, testing can find them.
Bituminous membranes
Bitumen roofs can often be tested electronically, depending on what’s below.
What you can safely check yourself
Watch the gutters in a downpour, from a window or the ground. Overflowing water can be a sign of a blockage or a gutter that has dropped.
It’s useful to keep a record: dates of leaks, photos from ground level and any work done on the roof. Share it with us when you book.
Hornsey questions
Is parking a problem for a survey in Hornsey?
It rarely stops a survey, but it’s worth planning. Let us know the parking rules on your street and we’ll work around them.
How do I find out if my home in Hornsey is listed?
Start with Historic England’s list for listing and your council for conservation areas. It is worth checking before planning roof work, as both can affect what’s allowed.
What if it rains on the day?
Light rain is normally fine; heavy rain and wind are different. High wind or heavy rain can make access unsafe and ground a drone, so we’d move the date with you.
Can you inspect my roof with a drone?
Where it helps and it is safe, yes. Whether we can fly on the day depends on the weather and the airspace rules, and we check for restrictions near airports before flying. We hold a CAA Flyer ID and Operator ID.
How experienced are you?
Over 5,000 surveys so far, across 20+ years of surveying roofs.
What’s the best way to book?
Simply ring 07833 053749 or email us. We will ask a few questions, confirm the price and agree a date, weekday or weekend.
Can you find leaks on a covered flat roof?
It can be possible, depending on the roof. Covered roofs limit the methods we can use, so we check the build-up first.
Flat and commercial roofs around Hornsey
Inner London’s Victorian and Edwardian terraces often have Welsh slate roofs. Behind many of their parapets sit butterfly roofs and valley gutters that can’t be seen from the pavement. If your home in Hornsey is one of them, lead flashings, party-wall upstands and shared chimney stacks are part of the picture too. Mixed in with those pitched roofs are a good many flat ones, over rear extensions, dormers, garages and shops. Bruce Castle, about 2 miles north-east, is one of the historic houses in the wider area around Hornsey. If you own one of the older houses, expect a mix of original materials and later repairs on the roof, and a listed home or one in a conservation area may need consent for changes of material.
If you look after a building like St Mary's CofE Primary School, large flat roofs, common on schools and other public buildings, need their outlets, upstands and coverings checked regularly. As a London address, Hornsey can be tricky for parking: tell us about permits, visitor bays or off-street space when you book, as a space near the door cannot be promised.
Hornsey is about 3 miles east of Finchley, in Greater London. Hornsey gets the same service as everywhere else we work: a careful inspection, photos and a written report. We cover towns and villages across Greater London, large and small. You can also see our page for London.
Electronic leak detection in N8 and N22 work the same way as everywhere else we cover. If you need electronic leak detection at a property on High Street, Brandon Place and Cross Lane or a nearby road, we can help. We also cover the places around Hornsey: Turnpike Lane (1 mile east), Crouch End (1 mile south-west), Stroud Green (1 mile south-east), Wood Green (1 mile north-east) and Noel Park (1 mile north-east). Within a short drive, we also cover London (6 miles south), City of Westminster (5 miles south), Marylebone (5 miles south), Kensington (7 miles south-west), St Pancras (4 miles south) and Shoreditch (5 miles south).
What’s near Hornsey
We work in homes and buildings around Great Northern Railway pub, Priory Park and Greek Secondary School of London. Hornsey has its own railway station: Hornsey station. Other landmarks nearby include Hornsey Central Hospital (0.7 miles west) and Broomfield House Museum (2 miles north). Open spaces near Hornsey include Darland's Lake and Highgate Hill.
How the survey works
The visit has one job: to look at the flat roof membrane as closely as is safe and record what we find. Everything we note and photograph goes into the written report. The visit normally takes longer on a large roof than a small one, with the construction of the roof playing a part too. In a London conversion, the way into the loft space is often from a communal landing or the top flat. Where that’s the case, access needs agreeing with whoever controls that landing. Everything else is planned around the building, not the postcode.
- We agree the area to be tested.
- The surface is prepared for the chosen method.
- Testing runs across the agreed area.
- Each breach found is located and recorded.
- The report is sent for your roofer to act on.
How to prepare
- If you are buying, let the agent know when we’re coming
- Note where any stains or damp appear
- Have keys ready for side gates, garages or roof access doors
Booking a survey
You can call us seven days a week, including Saturdays and Sundays. For a price or to book, ring 07833 053749 or email us.
Read more
Towns and villages near Hornsey
What else we do in Hornsey
Common roof problems in Hornsey
A breach can be left during installation. ELD on a new roof can show holes before they cause leaks.
People normally book a survey after spotting one of these:
- Gaps at membrane joints
- Repairs that haven’t stopped the leak
- Leaks through a flat roof with no obvious cause
- Leaks through a covered membrane
Shop and office owners around The Mall Wood Green may find that outlets and upstands on commercial flat roofs are the places to check before trouble starts.
Before you book any roof surveyor
- Whether the loft space is looked at, where there is one
- What the report includes, and whether it has photographs
- What follow-up you get after the report
- Their drone registration, if they fly one
What this survey can’t tell you
Before booking, it is worth knowing what a survey won’t do:
- Parts of the roof covered by fixed equipment
- Some conductive membranes
- Moisture spread under the membrane
If in doubt, phone 07833 053749 or email us and we’ll point you to the right survey before you book. The full list of what we check.
What this survey covers
- Liquid-applied waterproofing
- Flat roof membranes
- Roof terraces and balconies
- Commercial flat roofs
- Single-ply roofs
- Green roofs