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Thornton Consulting were recently appointed to undertake building leak investigations at a shopping centre in Essex.

The building was constructed in the 1960’s and consisted of retail units at ground level with residential block above. A car park was built on the first floor directly above the retail units and was waterproofed with asphalt.

Although throughout the life of the building numerous repairs had been undertaken, upon initial inspection some areas of deteriorated asphalt were observed, typical of its age.

The first phase of the building leak investigations process was to undertake electronic leak detection of the exposed asphalt car park to locate all areas where breaches had developed. The car park consisted of a mastic asphalt waterproofing layer with paving grade and rolled asphalt finishes. The electronic test was undertaken by the low voltage or “wet” test method which is a highly accurate test for locating breaches in waterproofing systems such as this. Numerous breaches were detected in the vicinity of the leak sites, many of which were significant in size.

To confirm the source of the leaks a procedure of positive testing was undertaken to recreate the leak by means of simulated rainfall test and bunded flood tests. (If necessary, these tests can also be undertaken using a trace dye to differentiate between tests to various locations, or elements of the structure.)

The water tests confirmed the majority of leaks were associate with breached asphalt waterproofing and all areas were clearly marked on the roof surface for the roofing contractor appointed to undertake repairs.

Additional testing was undertaken to the leaks that remained and included simulated rainfall tests to a parapet at the perimeter of the roof accompanied by a borescope inspection of brickwork to establish the construction of the perimeter wall. This indicated a fault with the cavity tray which was confirmed as the source of the leak following repeated water tests.

Accurately establishing the source of a leak though Building Leak Investigations undertaken by Thornton Consulting’s experienced team of consultants and field technicians is an invaluable service for Building owners, landlords, Facilities mangers, Construction companies, Roofers and many more, alike.

By pinpointing the source of the leak, targeted repairs can be undertaken to resolve the leak efficiently and economically with minimal disruption to building owners and occupiers.

For further information on our Building Leak Investigations service, please contact our office on 01342 410508