Hertfordshire · London and the South East
Electronic leak detection in Welwyn, Hertfordshire
Electronic leak detection in Welwyn, with over 20 years’ experience behind it. Every survey ends with a written report and photographs.
- Leaks that return after repairs
- Failed seams and laps
- A flat roof leak that can’t be traced
Why get it checked now?
Patching where you think the leak is often misses it. ELD shows the actual breach points. Around Welwyn, a leak in an older house can soak into timbers and plaster, and that’s a much bigger job than the original defect.
Larger roofs, taller buildings and commercial roofs take longer, so they’re priced to match. You will know the figure before booking.
Why choose Independent Roof Survey in Welwyn
- Drone and thermal imaging surveys available
- PI and public liability insurance
- CAA-registered drone operator (Flyer ID and Operator ID)
- 5,000+ roofs surveyed
Take a look at our cost guide or what we found on two real jobs.
About our electronic leak detection in Welwyn
ELD suits many waterproofing membranes on flat roofs over offices, units, blocks of flats and homes. It can be used to trace an existing leak or to test a new membrane before it’s covered. Each roof is quoted on its size and build-up. We can test on weekdays and at weekends when conditions allow. Just ask about your roof. Common reasons to book are breaches hidden under paving or planting and stains far from any visible defect, across liquid-applied waterproofing, flat roof membranes and single-ply roofs.
In a smaller place like Welwyn, some flat roofs sit in the open, so wind catches loose edges and trims. Sun on a flat roof also ages felt and bitumen. The signs are splits, blisters and edges coming away, along with water that sits after rain. Standing water that lingers for days after rain is another sign worth watching for.
Every survey ends with a written report, with photographs, emailed to you. It sets out the condition of the flat roof membrane, any defects and our written recommendations.
- Location
- Welwyn (AL6)
- Wider area
- Hertfordshire
- Cost
- Quoted for your roof
- Report
- Emailed report with photos and recommendations
- Appointments
- Monday to Sunday, daytime
- Insurance
- PI and public liability insurance
- Telephone
- 07833 053749
- Last updated
- 27 October 2026
Nearby places to Welwyn
What else we do in Welwyn
Welwyn questions
How do I find out if my home in Welwyn is listed?
The council and Historic England’s list are the places to check. It is worth checking before planning roof work, as both can affect what’s allowed.
Is Welwyn in the area you cover?
Yes. We cover the whole of London and South East England, and Welwyn is part of that. Just call 07833 053749 or email us and let us know about the property, and we’ll talk through which survey suits.
Is the repair part of the test?
No, the test finds the breaches and your roofer repairs them. The report gives your roofer the locations.
How long will testing take?
The roof’s size and build-up decide how long it takes. You will know roughly how long before we start.
How long have you been surveying roofs?
More than 5,000 surveys over 20+ years.
Is it the same as a RICS Level 2 or Level 3 survey?
No. Our survey looks at the roof, not the whole building. If you need a full building survey, you will need a RICS survey as well.
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.
What affects the price in Welwyn
What a survey costs depends on the time and equipment it needs. The main factors are:
- Height and safe access
- How complicated the roof is, with its valleys, chimneys and parapets
- Extensions, dormers and garages with roofs of their own
- How big the roof is
For a price for your roof in Welwyn, call 07833 053749 or email us with the address and a few details. We will confirm the figure before booking.
What we need to know
What helps most when you contact us:
- Any stains, drips or damp patches you’ve seen indoors
- The type of building and roof, like pitched or flat
- The address and postcode of the property
- Access details, such as a loft hatch or a shared roof
Booking is simple: just ring 07833 053749 or drop us an email, let us know about the property and we will recommend the right survey. The price is agreed up front.
Local flat roofs in Welwyn
Historic houses like Digswell House, about 0.9 miles south-east, show how far back building in the area around Welwyn 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. Older houses in the South East often have slate or clay tile roofs, while many later estates have concrete tiles, and flat-roofed additions turn up almost everywhere. Flat roofs on extensions, dormers, garages and business units are found alongside them almost everywhere.
Anyone responsible for a site like Monk's Walk School will know that ponding and blocked outlets on a wide flat roof are worth catching before the next wet season. For an older house near a landmark like Parish Church of St Mary, the flat roofs on later extensions tend to wear out long before the main roof.
Welwyn is about 2 miles north-west of Welwyn Garden City, in Hertfordshire. Roofs in Welwyn get the same thorough look as anywhere else in Hertfordshire. Across Hertfordshire, we cover Welwyn. You can also see our page for London.
Electronic leak detection in AL6 are booked the same way as anywhere else. You’ll find streets such as High Street, London Road and Mimram Place, all of which we cover. Other places close to Welwyn include Monkswood (1 mile south-east), Ayot St Peter (1 mile south-west), Ayot Green (1 mile south-west), Pottersheath (2 miles north) and Codicote (2 miles north-west). Larger places within reach include Watford (14 miles south-west), Hemel Hempstead (12 miles south-west), Stevenage (6 miles north), St Albans (7 miles south-west), Harpenden (6 miles west) and Hitchin (9 miles north).
Around Welwyn
We work in homes and buildings around Stable Door pub, Danesbury Park and Homerswood Primary and Nursery School and the streets around them. The nearest railway station is Welwyn North station, about 1.1 miles south-east of the centre. Nearby you’ll also find Queen Elizabeth II Hospital (3.5 miles south) and Datchworth Museum (2.7 miles north-east). Open spaces near Welwyn include Mardley Heath.
The survey, step by step
We look at the roof from outside and, where it’s relevant and there’s safe access, from inside the loft space too. Inside, we look for staining, damp, gaps and signs of movement, as far as the space allows. All in, the survey typically takes longer on a large roof than a small one, with the construction of the roof playing a part too. Homes around Welwyn often have gardens on more than one side, which gives us room to step back and see the roof. Let us know if any side is fenced off or hard to reach. The loft, where there is safe access, completes the picture.
- We start with what you know about the roof and the leak.
- 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.
- You get a report with photos of each breach.
Before we arrive
- Keep pets inside or away from the areas we are looking at
- Unlock side gates and any roof access doors
- Note where any stains or damp appear
Arrange a survey
Most bookings start with a short call: ring 07833 053749 or drop us an email. The price is agreed before a date is set.
Related advice
Roof by roof
Bituminous membranes
ELD is often possible on bituminous membranes, depending on what’s below.
Single-ply membranes
ELD frequently works on single-ply membranes, depending on the type and build-up.
Signs you need electronic leak detection in Welwyn
Flat roof membranes can be punctured by foot traffic, dropped tools or debris. Some are too small to see, but still let water through.
Problems we come across often include:
- Waterproofing to test before it is covered
- Failed seams and laps
- Leaks through a covered membrane
- Water coming in under a flat roof
If you run a business near Howard Centre, flat roofs over shops and units are easy to forget until water comes through a ceiling.
Before booking any roof surveyor
- What they will not be able to tell you
- Are they insured for the work?
- Which viewpoints they use to see the roof
- How long they’ve been surveying roofs
What we cannot see
To be straight with you, a roof survey has limits:
- The extent of water in the insulation
- Areas we can’t reach or that cannot be tested
- Roofs whose membrane or build-up isn’t suitable
If you’re not sure which survey you need, call 07833 053749 or email us and we will give you a straight answer. What our survey covers.
Roofs we survey in Welwyn
- Flat roof membranes
- Roof terraces and balconies
- Liquid-applied waterproofing
- Commercial flat roofs
- Green roofs
- Single-ply roofs