Flat roof leaks can often be inevitable on waterproof membranes that have been installed for some time or have been exposed to substantial traffic. However, determining if a flat roof should be replaced or refurbished is a critical decision for any client and can have a significant impact both in terms of cost and from an operational perspective. To establish this decision, it is vital to assess and understand the waterproofing integrity of the flat roof membrane.
Traditionally, the method of testing for flat roof leaks has been to ‘flood test’ the roof. This can be expensive, protracted and depends on considerable leakage through the roof, which can produce further damage. This method purely confirms that a leak exists but cannot determine where the water is actually penetrating the building. An alternative, well established method which is highly effective for identifying, locating and assessing defects in flat roof membranes is Electronic Leak Detection (ELD). The ELD method is non-invasive and will find any failings within the waterproofing membrane with pinpoint accuracy. It is a quick and efficient technique that can be used on most types of flat roofs. ELD can provide the option of carrying out extremely targeted repairs, if viable, as opposed to having to potentially remove and replace the complete roof surface.
For waterproof membranes on new roof installations, ELD also provides an accurate measure that the waterproofing is fit for purpose and provides clients with genuine reassurance that their roof structure is secure. The method relies on specialist, portable test equipment that produces a stable high voltage frequency over the flat roof membrane, which remains dry. This is carried out at a low currency level for safety purposes. If water lies below the membrane, the leak position that exists allows the electrical current to be discharged, thus identifying the area requiring repair.
It is recommended that this service is only carried out by an experienced operative. HBS are currently undertaking a number of high profile flat roof projects where ELD is being used. This includes the Sainsbury’s headquarters in Holborn where the 3000 m2 inverted flat roof has been replaced with a liquid roofing membrane. ELD is invaluable when carrying out inverted roof refurbishments because the testing is carried out prior to the roof subsequently being covered with insulation, shingle, paving or organic matter in the case of a green roof.
Electronic Leak Detection Summary
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