Building Leak Investigations | Emergency Leak Detection

Established in 1986

Pioneers of electronic leak detection in the UK

Over 35,000 successful tests

Excellent Client Reviews

Specialising in commercial and large residential properties

We offer this service when a there is a known leak somewhere in a building and the source needs to be identified.

We work on both new or old buildings of any size, but our speciality is in commercial buildings or large domestic buildings such as blocks of flats, hospitals, factories, sports centres and public buildings such as libraries.

Leaks can manifest in any part of a building such as beneath the roof, through a wall, above windows, or into the basement. We will identify the source of the leak and advise our clients on the necessary repairs required to resolve the problem

How We Test

There are many possible leak sources from the roof waterproofing and glazing to cladding and poorly sealed pipe penetrations, therefore we have a range of testing methods that we use to resolve the problem quickly and efficiently, depending on where the leak is.

Electronic Leak Detection

The process involves electronic leak detection of the waterproof covering and is typically undertaken by one of two methods, depending on the roof build-up and waterproofing to be tested. Both test methods rely on the electrically conductive properties of the substrate and insulating properties of the waterproofing for accurate detection of breaches and is suitable for most types of membranes. The test can be undertaken to both horizontal and vertical waterproofing, ensuring the entire roof is tested.

Flood Testing

This has largely been superseded by electronic testing as a means of establishing the waterproofing integrity of a roof or other installation. It can still be useful, however, where finishes are in place and electronic testing is impractical.

We have developed a system of creating flexible dams to improve the speed of preparatory works for instigating the flood test. Information is available on request.

Care must be taken when specifying flood testing and the following needs to be considered:

  • Will the roof take the weight?
  • What are the effects of major water ingress?
  • Who monitors it overnight?
  • Will the drainage system take the pressure of release?

Please feel free to get in touch if you require a flood test.

Moisture Profiles

This process uses an electrical capacitance technique, whereby electric discharge is reflected back by moisture, thus allowing high levels of moisture to be detected below the waterproofing membrane without disturbing it.

By measuring relative moisture content across structures such as roofs, a moisture profile can be developed that often points towards the leak source.​

Moisture profiling can also identify damage to insulation and provides guidelines as to whether the roof should be replaced.

This is typically combined with core samples of the roof which provide important information on the roof construction and allow accurate calibration of the test equipment.

Simulated Rainfall Test

The simulated rainfall testing technique is often used in conjunction with other tests to recreate a leak or confirm the integrity of a particular suspect item.

We have been using this process for over 30 years and have gradually refined the techniques so that it is rarely the case that a leak stays elusive for too long.

The technique is also used when other test methods are inappropriate or progress is best served by testing items identified on inspection as suspect.

Colourants are used only if absolutely necessary but are a valuable part of the diagnostic process.

Borescope Inspections

This borescope inspection technique, similar to an endoscope as used in medical applications but with a rigid probe, is an excellent diagnostic tool for checking and inspecting wall cavities in particular, as there can be many different problems deep inside that can lead to building leaks.

In addition, we also use flexible inspection cameras to investigate other areas of the building fabric where access is either restricted or otherwise impossible.

We can also combine a borescope inspection with simulated rainfall testing for greater accuracy and earlier diagnosis.

Ultrasound Testing

We use ultrasound testing to determine air paths in impermeable sections of the building envelope, especially glazing and curtain walling.

It is a vital part of our equipment, if for no other reason than we can eliminate these elements, thus allowing us to concentrate on other items.

Ultrasound readings are not always simple to interpret, so our experienced consultants know how to filter out extraneous sound. We normally combine this with simulated rainfall testing to confirm the problem.

Our Reports

A comprehensive test report covering all areas, images, and a marked up plan will be issued for each roof and test area completed at completion of the project.

Building Leak Investigations FAQs

1. What is a building leak investigation?

A building leak investigation is systematic process used to determine the source and cause of unwanted water ingress and damp in buildings.

2. What areas of the building can you investigate?
  • Roofs, balconies & terraces
  • Exterior walls & facades
  • Basements
  • Glazing & curtain walls
  • Loading bays & car parks
3. Can there be more than one source of the leak?

Yes. Buildings can experience multiple, simultaneous leaks. Our methodical approach—refined through decades of experience—is designed to identify and isolate each source, providing clients with clear, comprehensive information to support effective and targeted repairs.

4. What are the benefits of building leak investigations?
  • The source of each will be accurately located and diagnosed
  • Findings will be documented in a comprehensive report including photos and drawings
  • Eliminates guess work and is more cost effective than undertaking unnecessary repairs
  • Peace of mind for landlords, facilities managers, occupants or anyone with the responsibility of resolving a leak

Client Testimonials

I’ve worked with Thornton’s team for nigh on 10 years and I’m yet to be disappointed by any aspect of their business or interaction with any of their staff. I feel that the collaborative approach we have when working together not only benefits our site in a speedy response and solution, but it also strengthens our relationship with our onsite client team, building in faith that together we can self-solve most, if not all issues. Working with Wendy and the onsite teams is nothing short of a pleasure. I would highly recommend using Thornton Consulting Group for all investigative services when it comes to finding leak issues.

OCS Group (Bluewater)

Your team have successfully found the cause of the water ingress. I also wanted to write to express how impressed we are with the professionalism of both Sam and Dave and there health and safety whilst on site. I will be recommending Thornton Consulting going forward to the Hospital and will certainly use this service in the future with Carillion. Many thanks, and also for attending at such short notice.

Carillion Plc

We have worked with Thornton’s for several years now and we could not be happier with the service. The team are really helpful, accommodating and always happy to help us out if we are under pressure from a client. The team are always happy to take a call to discuss a project with them to get a clear understanding of the issues found on site. Thorntons always find the issues and provide a very thorough report to outline them with recommendations on repairs required.

Foxleys Fabrick & Building Maintenance

Thank you for your assistance with the DLI. The contractors used were fantastic and I would definitely recommend using them in the future.

Smart Property Development

Thornton Consulting are extremely professional, reliable and carry out a fantastic service with excellent communication throughout – we would recommend using them and we certainly will be using them again.

Rendall & Rittner

Just wanted to take a moment to commend your team for the works carried out on site. We are really pleased with the results.

TS, M

Thanks for the work carried out and the subsequent report. Sam and Dave were 1st class.

Complete Building Services Ltd

Building Leak Investigations Blog & Case Studies

To find out more about Building Leak Investigations and how we use it in our work read our case studies and blogs below.

Get in Touch Today

Call us on 01342 410508, email us at mail@thorntonconsulting.co.uk or send us a message using the form below. A friendly member of our team will be in touch shortly.

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