Hertfordshire · London and the South East
The Folly Electronic Leak Detection
Know where you stand with the flat roof membrane before you decide what to do next. Electronic leak detection in The Folly, with photographs and a clear written report.
- Leaks through a covered membrane
- Holes left by work on the roof
- Waterproofing to test before it is covered
Electronic leak detection in The Folly
You get a report showing the location of each breach with photos. It tells your roofer exactly where to repair instead of hunting for the leak. Repair costs aren’t part of the report, so your roofer prices the work. Testing again after repairs can confirm the breaches have been dealt with if the build-up allows. Results come in a written report with photos. Common reasons to book are gaps at membrane joints and leaks at pipes, outlets or fixings, across flat roof membranes, single-ply roofs and roof terraces and balconies.
Flat roofs on exposed homes in small places like The Folly take more wind and rain, so edges, upstands and laps take a beating. Felt roofs, which frequently last around 15–20 years, normally show it first. EPDM rubber and GRP coverings last longer, but their edges and joints still need checking. Exposed edges are typically the first part of a flat roof to go.
What you get is a clear record of the flat roof membrane on the day we saw it. It is useful straight away, and a good reference for later, such as when you want to compare after future work.
- Place
- The Folly (AL4)
- Region
- Hertfordshire
- Cost
- Quoted for your roof
- Your report
- Written, with photos, emailed to you
- Survey days
- Weekdays, Saturdays and Sundays
- Insured
- PI and public liability insurance
- Telephone
- 07833 053749
- Updated
- 27 October 2026
What we look for on each type of roof
Green and ballasted roofs
Testing before planting or ballast goes on is simpler.
Inverted and paved roofs
If the build-up rules out ELD, we’ll say so.
What this survey cannot tell you
In fairness, there are limits to any roof survey:
- Carrying out the repair work
- Areas we can’t reach or that cannot be tested
- How wet the insulation is
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 before booking. What our survey covers.
Roofs we survey in The Folly
- Commercial flat roofs
- Green roofs
- Single-ply roofs
- Liquid-applied waterproofing
- Flat roof membranes
- Roof terraces and balconies
DIY checks: what’s safe
A lot can be seen from ground level. With binoculars, look for slipped or missing slates and tiles, gaps along the ridge and leaning chimneys. Please do not climb up for a closer look.
Look up at the roof after a storm, from the ground: 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.
Local flat roofs in The Folly
Across the South East, older homes tend to have slate or clay tiles, and many later ones concrete tiles. Next to the main roofs there is typically a flat roof somewhere, whether on an extension, a garage or a commercial unit. About 2 miles north-east lies Shaw's Corner, a reminder of how long the area around The Folly has been built on. Older homes in the wider area often have features worth a closer look, like 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.
If your house is among the older ones in the streets near St Helen's Church, later flat-roofed additions are common on older houses, and their edges and upstands often show the first signs of wear. If you look after a building such as St Helen's Church of England Primary School, a large flat roof with a good many outlets and rooflights has many places where a membrane can fail.
The Folly is about 2 miles east of Harpenden, in Hertfordshire. Wherever you are in The Folly, we can carry out electronic leak detection at your property, on a weekday, Saturday or Sunday. The Folly is one of the places in Hertfordshire where we work for electronic leak detection. For surveys nearby, see our London page.
All of AL4 is covered for electronic leak detection, from the main roads to the quietest streets. We offer electronic leak detection to properties on Folly Fields and Lower Luton Road. We also cover the places around The Folly: Lea Valley (1 mile west), Amwell (1 mile south), Mackerye End (1 mile north-west), Blackmore End (1 mile north) and Batford (1 mile west). We also work in nearby towns like Watford (11 miles south), Hemel Hempstead (8 miles south-west), Stevenage (8 miles north-east), St Albans (5 miles south), Welwyn Garden City (5 miles east) and Hitchin (9 miles north).
Near you in The Folly
In The Folly, that means homes and buildings near Sir John Lawes School and The Cherry Trees pub and the streets around them. For rail, the closest station is Harpenden station, roughly 2 miles west. Other landmarks nearby include St Albans City Hospital (4.2 miles south) and Harpenden Museum (2.2 miles west). Not far away are Wheathampstead Local Nature Reserve.
The Folly: your questions answered
Do you cover smaller places like The Folly?
Yes, The Folly is covered. Our area covers London and the South East, and smaller places are part of that. The journey is planned ahead, so it helps to know about access.
How do I find out if my home in The Folly is listed?
Check Historic England’s online list first, then ask the council about conservation areas and any Article 4 direction. It matters most if you’re planning to re-roof in a different material.
Is this an asbestos survey?
No. Asbestos surveys and sampling are not something we do. Where a material might contain it, like old cement sheets on a building from before 2000, the report flags it, with a recommendation to have a specialist asbestos surveyor check before it’s disturbed.
Do you use drones?
Yes, where it is 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.
How experienced are you?
We have completed more than 5,000 surveys, across 20+ years of surveying roofs, with 98% customer satisfaction.
Are you insured?
We are covered by professional indemnity and public liability insurance, for every survey we carry out.
How do you choose the testing method?
The method is chosen to suit the roof. Low-voltage testing usually needs a wet surface and high-voltage methods need the membrane dry and exposed.
What happens on the day
We work from the outside in: first the slopes, edges and gutters from every safe viewpoint, then the roof space where it can be reached. All told, expect a length of time set by the membrane area and the build-up, which we’ll explain when we quote. Cottages and farmhouses around The Folly frequently have roofs at several levels, with lean-tos and outbuildings attached. Each part is looked at from wherever it can safely be seen, and anything we can’t see is noted.
- First, we confirm which roof areas are included.
- We get the roof ready for testing.
- We work across the roof with the test equipment.
- Each breach found is located and recorded.
- You receive the results to pass to your roofer.
Preparing for the visit
- Agree roof access with the managing agent if it is shared
- Make a note of anything you’d like us to look at
- Check we can get to the back of the property
Getting a price
For a price for electronic leak detection in The Folly, call 07833 053749 or use the contact form. Some details about the property and the roof help us give you an accurate price.
Read more
Surveys for landlords and agents in The Folly
Letting agents and landlords in The Folly book surveys as well as householders. The report gives you a dated record of the flat roof membrane, with photographs, which helps you plan work between tenancies.
Any of our surveys can be booked by landlords, agents and building managers in The Folly. For a price for a let property or a block, phone 07833 053749 or drop us an email.
Also near The Folly
More services for The Folly
Common roof problems in The Folly
Seams are a common weak point in flat roof waterproofing. A gap that is hard to see can let water in long before anyone notices.
These are some of the problems a survey can pick up:
- Holes left by work on the roof
- Gaps at membrane joints
- Leaks under green or ballasted roofs
- Breaches around outlets and penetrations
Landlords with a home close to Harpenden station may find that the flat roof over a let home is worth a look before it becomes a tenant complaint.
Before you book any roof surveyor
- Which viewpoints they use to see the roof
- What they will not be able to tell you
- Their drone registration, if they fly one
- Will the report include photos?