A primary benefit of fiberglass swimming pools is their high durability inside and out. Both the structure and the surface of a high-quality fiberglass pool can last many years, provided you properly maintain your pool. The gelcoat on a fiberglass pool is intended to last the lifetime of the pool without needing to be replaced. If a fiberglass pool needs to be resurfaced, it is generally only after decades of regular use.
Lets face it the earth moves and the dirt beneath us moves over time, which is often the reason for cosmetic or even structural cracks that can appear in concrete pools. Fiberglass is strong and durable, but it also maintains a flexibility that allows it to move with the earth and refrain from cracking as long as it has been backfilled properly. Unpredictable, rapidly changing weather may also cause damage to other kinds of pools. The expansion and contraction of water in the cold or heat may also apply stress pressure that would cause cracking on other types of pools. Fiberglass pools are much better able to resist such damage.