Swimming and Spa Pools

Why Use Stainless?

Stainless steel is a popular choice for pool areas because of its long life, low maintenance costs, design flexibility, and hygienic benefits. Its ease of bacteria, virus, and algae removal is comparable to glass, making it the hygienic choice for pool applications, therapy facilities, and other applications where cleanability is critical.

Seismic performance is an additional important benefit. Stainless steel swimming pool liners have withstood earthquake damage under conditions where traditional concrete and fiber-reinforced polymer (FRP) pool linings have failed.

 Design Advantages

While most people are familiar with the classic applications for stainless steel, many popular new design concepts are naturally suited to this flexible material. These include integral fountains, infinity edges, and other creative elements. Vacation venues and theme parks use stainless steel liners for water rides, elaborate pools, and even endlessly flowing rivers with currents that carry bathers along their curving paths.  

Stainless steel’s design flexibility makes possible creative designs like this Type 316 continuously flowing beachside river.

Stainless steel pool liner and structural support systems are designed in advance and can be installed more rapidly than traditional systems. This is advantageous when relining commercial and public pools, and for new construction projects when it is desirable to limit construction disruption and pool closure time.

Spa & Therapy Pools

Therapy pools were one of the early applications for stainless steel liners because of their hygienic requirements, but stainless has also become popular for the growing number of spa and hot tub pools found in private residences, resorts, and public facilities.

Spa, therapy and hot tub designs for commercial and private installations are limited only by the imagination.

The higher temperatures used in these pools can increase bacteria and virus levels. Higher chlorination levels are typically used to disinfect them, making these application environments more corrosive than that of the typical recreational pool. Stainless steels are a logical choice, but Type 316 or a more corrosion resistant molybdenum-containing grade should be selected.

Specification

Appropriate stainless steel specification depends on the water sanitation method (e.g. chlorination or bromination) and concentration, water temperature, and the type of application. Particular care is needed when selecting steel for load-bearing structural applications near ceiling level, and for elevated-temperature pools with high chlorination levels.

For exterior water features, pools, and fountains, designers should consider the effects of evaporation on chlorine concentration. This is particularly true in hot, arid environments. When these conditions exist, automatic or regular manual monitoring is suggested so that water chemistry can be adjusted to avoid excessively high chloride levels. Care should also be taken in areas where potable water is naturally high in chlorides.

Water treatment to reduce mineral content should be considered when there are high levels of dissolved solids (hard water), because evaporation of splashed water may result in mineral stains. These can be removed, but this increases maintenance costs. Excess iron in the pool water supply should always be removed to prevent staining.