Hertfordshire · London and the South East
Welwyn Garden City Electronic Leak Detection
Electronic leak detection in Welwyn Garden City, backed by more than 20 years’ experience. Every survey ends with a written report and photographs.
- A flat roof leak that can’t be traced
- Leaks through a covered membrane
- Gaps at membrane joints
Electronic leak detection for homes and businesses in Welwyn Garden City
ELD is a way of pinpointing breaches in a flat roof’s waterproofing membrane. It works with an 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 knows exactly where to repair. You get a photo-illustrated written report of each breach found. We’re often asked to look into damp inside with no sign on the roof and new membranes needing a check before handover, on roof terraces and balconies, commercial flat roofs and liquid-applied waterproofing.
In a town like Welwyn Garden City, flat roofs are common on rear extensions, garages, porches and dormers. Many are felt, and newer ones may be EPDM rubber or GRP. Ponding water, splits along the edges and lifting upstands are the usual warning signs. Water that sits for days after rain is often the first sign a flat roof needs attention.
Findings are set out part by part, from the main slopes down to the gutters and outlets, each with a short note and a photo. You’ll see the good as well as the bad.
- Place
- Welwyn Garden City (AL7, AL8, AL6)
- Wider area
- Hertfordshire
- Prices
- Quoted for your roof
- Report
- Written, with photos, emailed to you
- When we survey
- Weekdays, Saturdays and Sundays
- Insured
- PI and public liability insurance
- Call
- 07833 053749
- Last updated
- 27 October 2026
How it works
The visit typically starts outside and finishes in the loft: first the slopes, edges and gutters from every safe viewpoint, then the roof space where it can be reached. All told, expect longer on a large roof than a small one, with the construction of the roof playing a part too. In Welwyn Garden City, parking is rarely complicated, though it is useful to know about driveways or restrictions. We check the roof from the ground and from windows, then from the loft where there is safe access.
- We agree the area to be tested.
- 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.
How to prepare
- Show us where any leaks or stains appear
- Leave side gates unlocked
- Agree roof access with the managing agent if it’s shared
Arrange a survey
To arrange a survey, call 07833 053749 or send us an email with the address and what you’d like to know about the roof. You will know the price before anything is booked.
Related advice
Why it’s worth a survey now in Welwyn Garden City
Testing a new membrane before it is covered is easier than tracing a leak later. Covered roofs are harder to test. Extensions and dormers on homes around Welwyn Garden City frequently hide the first signs of trouble at their joints with the main roof. Left for a few seasons, it can spoil plaster, skirting and flooring inside.
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 safely it can be seen. We quote electronic leak detection for each roof, as the method and time depend on the roof.
Why choose Independent Roof Survey in Welwyn Garden City
- Over 20 years’ experience
- Customer satisfaction of 98%
- Insured for professional indemnity and public liability
- An independent look at the roof
Places near Welwyn Garden City
More services for Welwyn Garden City
FAQs for Welwyn Garden City
Do you carry out roof surveys in Welwyn Garden City?
Yes, Welwyn Garden City is one of the places we work. The survey and report are the same in Welwyn Garden City as anywhere else, and visits run on weekdays and weekends.
Is my home in Welwyn Garden City listed or in a conservation area?
Start with Historic England’s list for listing and your council for conservation areas. It’s worth checking before planning roof work, as both can affect what’s allowed.
Do I need to be at home?
That depends on the survey. For inside areas and the roof space, someone has to give us access; we’ll agree the details when booking.
Will I get photos?
Yes. The report includes photos of what we found, so you can see exactly what each finding refers to.
Do you need to get into the loft?
Usually, if there’s one and it can be reached safely. From inside, the underside of the roof often shows damp, staining or daylight that can’t be seen from outside.
Does the weather affect the survey?
Light rain doesn’t usually stop a survey. Strong wind or a downpour can stop drone flights and make roof access unsafe, so we will agree a new date if the weather isn’t suitable.
Can you test a green or ballasted roof?
It can be possible, depending on the roof. Covered roofs limit the methods we can use so we look at the roof first.
Prices for electronic leak detection in Welwyn Garden City
Not every roof costs the same to survey, and it comes down to:
- The size of the roof
- How many separate roofs there are, such as extensions, dormers and garages
- Any need for thermal images or a drone flight
- House, block, shop or office
All our prices include VAT. We quote electronic leak detection for each roof, as the method and time depend on the roof. We confirm the price for your roof before booking.
What to tell us when you get in touch
Getting the details right at the start saves time. Please include:
- Anything about access we should know
- Dates you are working to, such as exchange
- The style of property, from a terrace to a block
- Where water is showing inside, if it is
Every survey is priced before it is booked, so you know the cost up front. We quote electronic leak detection for each roof, as the method and time depend on the roof. For a price for your roof, phone 07833 053749 or email us.
Common roof problems in Welwyn Garden City
Other trades on the roof can puncture the waterproofing. Engineers fitting equipment, solar panels or aerials may leave damage behind.
These are some of the problems a survey can pick up:
- Leaks through a covered membrane
- Patched roofs that still leak
- Leaks showing away from the breach
- Failed seams and laps
Take an older house close to Church Of Saint Francis Of Assisi: the joins between later flat roofs and the old walls are where problems usually start.
Questions to ask before you book
- Whether the inside of the roof is included
- What exactly goes into their report
- Whether VAT is in the quoted price
- How long they’ve been surveying roofs
Flat roofs in Welwyn Garden City
Across the South East, older homes tend to have slate or clay tiles, and many later ones concrete tiles. Flat roofs on extensions, dormers, garages and business units are found alongside them almost everywhere. About 1.5 miles north lies Digswell House, a reminder of how long the area around Welwyn Garden City has been built on. Older homes in the wider area frequently have features worth a closer look, such as lead valleys, tall stacks and roofs that have been patched over the years.
For businesses in and around places like Howard Centre, outlets and upstands on commercial flat roofs are the places to check before trouble starts. For site and facilities teams at buildings such as Peartree Primary School, large flat roofs, common on schools and other public buildings, need their outlets, upstands and coverings checked regularly.
Welwyn Garden City is in Hertfordshire. Roofs in Welwyn Garden City get the same thorough look as anywhere else in Hertfordshire. Welwyn Garden City is one of the towns and villages in Hertfordshire where we work for electronic leak detection. Our London page covers surveys nearby.
Postcode districts we cover here for electronic leak detection: AL7, AL8 and AL6. We cover properties on Church Road, Station Road and Lynmouth Road. With the B195 and A1000 close by, Welwyn Garden City is simple for us to get to. Nearby, we also carry out electronic leak detection in Hatfield Hyde (1 mile south), Letty Green (3 miles south-east), West End (3 miles south), Essendon (3 miles south-east) and Staines Green (3 miles east). Larger places within reach include Watford (13 miles south-west), Hemel Hempstead (12 miles west), Stevenage (8 miles north), St Albans (7 miles south-west), Harpenden (7 miles west) and Hitchin (11 miles north). As one of the bigger places in Hertfordshire, Welwyn Garden City has every kind of building, from houses and flats to offices.
Near you in Welwyn Garden City
We work in homes and buildings around Stanborough Park, Sir Frederic Osborn School and The Bakehouse pub, among other places. Welwyn Garden City’s nearest station is Welwyn Garden City station, roughly 0.5 miles west of the centre. Well-known places in the area include The Bunker at Hatfield Police Station (2.9 miles south-west) and Queen Elizabeth II Hospital (1.1 miles south). For a walk, there’s Lemsford Springs.
Roof by roof
Bituminous membranes
Older felt roofs often have seams and patches where breaches occur. Testing depends on the roof.
Inverted and paved roofs
If the build-up rules out ELD, we will say so.
Can I check my roof myself?
After heavy rain, check ceilings and the tops of walls for new stains. Photograph them and note the date, as it helps a surveyor trace the cause.
What you can’t do safely is get up close. Roofs are fragile and slippery, and falls from height are serious. That’s where a survey comes in.