Can Cracks in Fiberglass Swimming Pools Be Fixed?

Types

• There are two major types of cracks that can occur in a fiberglass swimming pool: structural cracks and spider cracks. A structural crack is a larger, deeper crack in the fiberglass lining itself. Spider cracks are extremely tiny stress cracks that are found on the top finishing layer, also called the gel coat. Spider cracks get their name from their spider web-like appearance and do not cause significant problems because they do not extend to the fiberglass lining or structural components of the swimming pool.

Methods

• Structural cracks in fiberglass will need to be filled with a special polyester putty, which is then smoothed down with a putty knife and allowed to fully harden. A new fiberglass finish and top coat is placed over the putty.
  Spider cracks cannot easily be repaired and generally require the entire pool being re-coated with a special manufactured gel coating material. This is because spider cracks spread quickly throughout the entire top coat surface of the fiberglass. To repair these cracks, the pool will need to be drained and allowed to fully dry and then coated with gel coat. The gel coat will need to be allowed to cure for as long as the product label specifies.

Issues

• Large structural cracks in fiberglass need to be filled and repaired as soon as possible to avoid the swimming pool beginning to leak. The only issue with spider cracks is an aesthetic issue. In most cases, the spider cracks are tiny, hairline cracks that are nearly impossible to see with the naked eye, but if they are larger they may be visible. These cracks do not affect the structural integrity of the swimming pool.

Prevention

• Structural cracks in fiberglass pools do not occur normally and are usually the result of something hitting the side of the pool, such as a rock. As a result, these cracks can be difficult to prevent.
  Preventing spider cracks is important because of the difficulty in repairing them. These cracks are most likely to occur if the pool is improperly installed in the first place and not able to withstand the shifting of the ground around it. To avoid spider cracks, choose a reputable pool installer.