There is no other part of a hot tub more critical to investigate prior to buying than the shell. If any other component (pump, heater, filter, jet, etc) should falter it could easily be replaced. If a shell fails, the repair or replacement could be prohibitive. Even if it’s under warrantee, most manufacturers do not cover the cost of delivery. This alone can amount to thousands of dollars.

Determining the quality of a shell cannot be accomplished simply by viewing it’s outer surface. Nearly all manufactures today use Acrylic for the surface of the shell so virtually all spa shells, aside from contours, pillows, grab bars, etc all look the same. To determine the quality and longevity of the spa shell it is important to understand the different construction techniques and to know the best questions to ask.

The traditional spa shell is made from a variety of materials; Continuous Cast Acrylic and a Laminate Composite. Each is dependent upon the other to provide a long lasting, quality product. The Continuous Cast Acrylic is the outer surface of the Spa Shell that provides the color, the feel, and the texture of the spa shell. This is the part you see and sit upon in the hot tub. A hot tub shell is constructed by setting a large flat sheet of acrylic into an oven, heating it to pliable state, and vacuum forming it into a given mold. The important part of the forming process is the care and technique the manufacturer takes in making certain that thickness of the acrylic is uniform throughout the shell. In a good quality spa shell you shouldn’t see any signs of light passing through in the critical areas of the foot well where the acrylic sheet could have been pulled the thinnest. Thin areas of the acrylic surface could eventually result in stress cracks in the future.