The Strongest Shells
Coast Spas® has partnered with Owens Corning® to Deliver the Toughest and Most Durable Hot Tub Shells Available.

Your hot tub starts its life as a sheet of premium acrylic. It is then heated and vacuum-formed to take on the shape of a hot tub, at this point the acrylic is fragile and flexible. The acrylic shell is then moved to be reinforced using high-grade Owens Corning® fiberglass. A team of specialists start by applying several layers of fiberglass to the shell, then use rollers to compress those layers together. Steel angle iron is then placed onto those first compressed layers for additional support in specific structural areas. Additional layers of Owens Corning® fiberglass are then added (up to 12 layers or more are typical for an average-size Coast Spas Model) and compressed again, by hand, to complete the shell.reinforcement.


Your Hot Tub or Swim Spa shell is not just one of the most expensive components of your spa, but also the only piece that can never be replaced. If your hot tub cracks, there is no real avenue for structural repair - and your hot tub will no longer be able to be used. Your spa shell is responsible for containing a large volumes of water that has a significant amount of weight. This weight is constantly applying immense pressure to your shell and its integrity has to hold even when faced with environmental fluctuations in temperature and humidity. Ensure your next hot tub has the strength and durability of multi-layer Owens Corning Fiberglass and steel reinforcement.