Hot Tubs

You've decided to buy a hot tub or spa. Now you have to decide whether you should buy an above-ground unit or a pre-plumbed inground unit. You also need to consider what type of shell material is best for your needs. Different materials have different maintenance and cleaning requirements. Some are also lighter than others, allowing for an easier move if you decide to remodel. Some of the more popular materials are listed below, with a short description and discussion of them.

Vinyl hot tub shells

Vinyl shells are usually the least expensive. Vinyl is more commonly found in what are termed "soft-sided" hot tubs and spas. Because it's a softer material, it is much easier to damage than other materials. It's also very susceptible to damage caused by incorrect chemical balances and long-term exposure to the sun. Discoloration caused by improper care isn't covered by the warranty.

Marbles and stone-like acrylic

Hot tubs and spas with acrylic shells are normally surfaced in acrylic and backed by fiberglass for strength and durability. This type of shell material can be easily cleaned with spa water and a brush. One major problem with this type of spa construction is that even though the bonding agents used during the manufacturing process have improved, they are still susceptible to de-laminating, where the two materials separate, causing bubbles to appear in the surface. When purchasing this type of spa, pay more attention to the surface warranty than other warranties.

ABS plastic-backed acrylic

This is a newer manufacturing process where the acrylic and ABS are extruded at the same time, eliminating the need for a bonding agent. Since they are co-extruded there is no worry of de-laminating occurring. However, hard foam is normally used as the stiffening agent with this type of shell construction, making leak detection and repair more difficult for technicians without the proper training. When purchasing a hot tub with this type of construction, be sure to purchase from a reputable company with an excellent reputation that offers an excellent warranty. Shiny acrylics will need to be waxed often to remove small scratches and waterline marks.

Thermal plastics: The up-and-coming shell material

Thermal plastics are pretty new as far as being used for the construction of spa and hot tub shells. They seem to offer a number of advantages over other materials. For example, most manufacturers offer a lifetime surface and structural warranty. As with any other material, check the credentials of the manufacturer before plunking down any money, since it's not hard to pull a shell with thin spots that can fail easily. Most thermal plastic shells use polyethylene that can turn brown under exposure to low pH levels, high levels of disinfectants, and low levels of rust in the water.