How Vinyl Pool Liners Fail
Vinyl pool liners fail through a combination of age-related degradation, physical damage, chemical exposure, and installation-related issues. UV exposure and chemical imbalance — particularly sustained low pH — make liner vinyl brittle and prone to tearing over time. A liner that has been in service for fifteen or more years may be structurally compromised even if no visible tears are present, making it susceptible to tearing from normal pool activity. Physical tears from sharp objects, pool cleaner snags, or improper vacuuming techniques are the most common cause of liner damage in newer liners.
Seam failures occur where two panels of vinyl liner are bonded together at the factory. Seams along the floor-to-wall transition and at corners are the highest stress points. As a liner ages and loses flexibility, seams can separate — particularly in Boston's climate, where freeze-thaw cycles and the stresses of seasonal pool opening and closing create mechanical fatigue at seam locations.