Electronic Leak Detection of an Aged PVC Flat Roof at a Sports Centre in the Southwest

Project Overview

Thornton Consulting were recently appointed to conduct an assessment of the aged waterproofing at a sports centre in the southwest of England. The roof consisted of single ply PVC waterproofing mechanically fixed to a metal deck.

The sports centre was approximately 40 years old although the roof had previously been replaced approximately 15 years ago. Nonetheless, it was important to determine the current condition of the waterproofing as the client wanted reassurance that the roof remained watertight.

PVC single-ply membranes are widely used on flat roofs due to their flexibility, durability and ease of installation. However, as with all waterproofing systems, performance can be affected over time by weathering, mechanical damage, foot traffic, plant maintenance, detailing failures and ageing of seams or penetrations. On a building such as this, it is important to remain proactive with roof maintenance, which includes periodic testing, to ensure the longevity of the roof.

Our Role

An electronic leak detection survey was, therefore, commissioned to test the integrity of the roof membrane. This non-destructive method uses electrical conductivity to identify breaches in the waterproofing layer. The roof area was systematically tested and inspected, with particular attention paid to vulnerable locations such as upstands, outlets, laps, roof penetrations and areas of previous repair.

The testing identified several points where the membrane had been compromised, including small punctures and de-bonded laps.

Each breach was marked on the surface of the roof and recorded on a marked-up plan, included with the report, providing clear information for a contractor to undertake remedial repairs.

The Benefits

The project demonstrated the value of electronic leak detection as part of a proactive roof maintenance strategy. For aged PVC flat roofs, periodic integrity testing can play an important role by accurately identify breaches and enabling targeted repairs, supporting a maintenance programme which can extend the serviceable life of the roof and helps reduce the risk of future water ingress.