 Resistance is measured by accelerated aging in a harsh controlled environment; the number of weeks survived is expressed as a "hydrolysis resistance" in units of years (expected under normal conditions).If PUL is kept wet for a long time, it disintegrates into the water and sticks to itself, though it will probably go mouldy first.If the polyurethane starts delaminating from the fabric, it may be possible to relaminate it with care and a hot iron.