‘Alligatoring’ refers to the cracking of the surface of a bitumen roof coating such as old asphalt, rubber, or liquid. The cracks often occur in a pattern that is reminiscent of an alligator hide. The cause of the cracks is a combination of UV from the sun, thermal cycles, weathering, and age. The appearance of these cracks is a cause for concern as it signifies breakdown of a roof’s waterproofing and could point towards imminent failure of the roof and a need to refurbish.
The advent of this alligator-skin pattern is common on old, high-level, flat roofs. These types of roofs bear the brunt of blazing summer temperatures, freezing winters and - as often as not - poor to zero maintenance.
Buildings such as blocks of residential flats, commercial buildings and offices can be prone to the cracking of old surface coatings. As a hardwearing material with low maintenance, bitumen roofs can be overlooked or forgotten about. This out-of-sight, out-of-mind issue can lead to the eventual failure of the roof.
Just as with real alligators in the wild, the cracks appearing in the membrane are not necessarily visible straight away. Often, they are lurking at the edges; small, unnoticed but potentially a danger when it comes to water ingress. Changes in direction such as upstands and corners are often weak points.
Knowing what to look out for is key when surveying a roof to ascertain its true condition. Often, on old roofs, patch repairs and temporary coatings maybe hiding a more in-depth problem.
Identifying the condition of a roof, and the best remedy to take if action is required, is one of the biggest strengths of our expert flat roofing team. A roof survey and subsequent roof refurbishment specification is available free of charge and has proved to be of great value to surveyors and building owners.
If you are concerned about the state of an ageing roof, contact Bailey Roofing Technical Department today to arrange a roof condition survey and report for your flat roof. Email firstname.lastname@example.org, complete a contact form on this website or call us on 01403 261 844.
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