Osmosis blisters are one of the main signs that a pool resurfacing may be required. They occur when the gelcoat becomes porous over time, allowing water to penetrate through the surface and become trapped within the fibreglass laminate beneath. As pressure builds, blisters begin to form on the pool surface. If left untreated, osmosis can eventually lead to further deterioration of the laminate and compromise the long-term integrity of the pool shell. To properly repair these areas, the affected blisters must be ground out and all weakened or contaminated fibreglass removed. The damaged sections are then rebuilt using resin and reinforced with new fibreglass matting before the surface is refinished.
