There are many things to consider when selecting a hydrotherapy tub. In a previous post I briefly described three types of system tubs; whirlpool, jetted and air baths. Deciding what type system is right for you is the first step. Once you know what kind of hydrotherapy you are looking for you can begin to consider materials, controls and features.
What are the Best Whirlpools made of?
Generally speaking tubs are made from one of four materials; cast iron, acrylic, cast resin or fiberglass. If you are looking for a system tub you can probably eliminate a cast resin tub from the start. Most manufacturers of these tubs do not offer system tubs, only soakers. There is one company, Six Eleven, which is the exception to this rule. Six Eleven offers tubs that can be customized by shape, system and many other features. I will cover resin tubs in more detail in a future post.
A well made, glossy cast iron tub can be a thing of luxury and beauty. In appearance cast iron offers a beautiful glossy surface that can support vivid colors. The density of the cast iron material also holds heat well (once it warms up!). If you want a cast iron hydrotherapy tub then you will probably be looking at Kohler. Kohler is by far the leading maker of cast iron tubs and also one of the only companies still offering cast iron hydrotherapy models. I think this is mostly due to the fact that very few companies still make cast iron at all and I think the reasons for this have more to do with the difficulties of working with cast iron than with the quality of the final product. Cast iron is harder to produce, it’s very heavy and so more difficult to transport. This tends to be more expensive. Finally, there is a characteristic to cast iron called “orange peel” which is a sort of bumpy surface that sometimes happens. It is not a defect but if you are after a smooth surface you may find this to be unacceptable (I recently ran into this with a client who rejected three cast iron tubs before finally switching to acrylic).
Today the great majority of hydrotherapy tubs we sell are made of acrylic. Acrylic should not be confused with fiberglass. While both types get the structural integrity from the fiberglass material there is a big difference in the finish. Acrylic tubs are made by molding a sheet of acrylic into a tub shape and then reinforced with fiberglass structure. With a fiberglass tub the fiberglass is molded into a shell and then sprayed with a “gel coat” to create a glossy surface.
An acrylic surface is more durable than a gel coat. It is much more resistant to scratches and will retain its shine better over time. Because it is non-porous it is easy to clean and can be buffed up occasionally with an application of car wax. You can find acrylic tubs in a great variety of shapes and sizes, from many manufacturers and with a big range of price points.
Acrylic tubs are lighter weight than cast iron but it would be a mistake to equate that with flimsiness. Well made acrylic tubs feel every bit as solid as cast iron and yet can be hundreds of pounds lighter, especially important in a raised floor application. However it is true that there is a wider range of quality with acrylic than with cast iron so be sure to buy from a well regarded manufacturer. There are many of them: MTI, Jason, Maax, Bain Ultra, Oceania, Neptune, Hydrosystems, Americh and many more. These companies make solid products and may incorporate details like self-leveling bases and pre-framed units for stability.
Fiberglass is the last material on the list and can be a good choice for certain situations. It can be more porous and softer than acrylic or cast iron so proper care is important to maintaining fiberglass successfully. I have fiberglass walls in the shower of the house I am renting and I do notice that a watermark appears if I leave a bottle of shampoo sitting on the surface. This does dry out and disappear but it a reminder not to let anything that might stain to sit on the surface.
Once you settle on a material the next thing to consider is the features and options available. I will talk more about those in my next post.