We have recently completed testing on a large car park, of approximately 10000m2, in the Midlands which was comprised of a concrete deck and paving grade asphalt system of mastic asphalt and wear course.
Although asphalt has become less popular for waterproofing roofs in recent years, it is still commonly used in car parks due to its waterproofing properties, durability and anti-skid resistance which can be provided in the wearing course.
Leaks were being experienced beneath the top deck of the car park and our client required our leak detection service to locate the source of each. In addition, there was a requirement to undertake an integrity test to the whole car park to locate all breaches in the asphalt waterproofing, this involved electronic leak detection of the exposed asphalt.
Electronic leak detection works particularly well with a construction such as this due to the electrically insulating properties of the asphalt and conductive properties of the substrate beneath. Where a water path exists through to the slab, this can be accurately located with our sensitive test equipment and identified as a breach in the waterproofing system.
For the duration if the test, the car park remained closed to traffic to ensure a safe working environment for our team. This also expedited the leak investigations as we were able to test multiple areas simultaneously with continued monitoring of the leaks beneath.
A number of different techniques were used to establish the source of the leaks, including simulated rainfall testing of suspect items, localised flood tests and internal moisture profiling to monitor for changes in damp. Positive results were achieved at all locations.
At completion of the survey a comprehensive report was produced for the client. This included:
· Results from the electronic leak detection test and locations of breaches marked on a plan
· Conclusions of the leak investigations confirming the source of each leak and recommendations for resolving the issues.
Testing as described above can be useful in not only finding the source of leaks, but also as a preventative measure allowing defects or breaches to be addressed before they become an issue. This is used by many of our clients as part of a planned maintenance programme.