On a flat or low-slope roof, blisters form when air or moisture becomes trapped between the membrane layers or beneath the membrane, then expands under the effect of heat and lifts the covering into bubbles.
Common causes
moisture trapped during installation, incomplete adhesion between layers, water vapour from inside the building migrating into the roofing system, or a design flaw in the membrane. Summer heat amplifies the swelling.
Signs to watch for
raised bubbles or blisters on the surface, soft or spongy areas underfoot, membrane lifting in places, water pooling around the blisters, sometimes cracks at the top of older bubbles.
Why you should not ignore it
a blister weakens the membrane where it forms; if it bursts, it creates a direct point of infiltration. It also reveals an adhesion problem or the presence of moisture in the roofing system, two factors that shorten the life of the covering and are worth locating and monitoring.
What a professional assessment reveals
A blister on a flat roof traps moisture or air beneath the membrane, weakening the watertightness. An assessment, supported by thermography, helps locate trapped moisture and tell an isolated defect apart from a widespread problem.
Blisters often signal a problem beneath the membrane. Our roof expertise maps them with thermography and tells them apart from simple membrane degranulation.
Vous soupconnez ce probleme dans un batiment ?
Une inspection le confirme, le documente et le chiffre, pour decider en connaissance de cause.
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