Site conditions
Prevailing site conditions, including groundwater, soil quality, overhead trees, freeze/thaw, and extreme temperatures—along with excessive UV exposure—will affect all types of pools and interior finishes. Careful attention to standard building practices, with particular emphasis on structural conditions of the pool shell, and avoidance of water infiltration will pay large dividends towards the longevity of all pool interiors.
Site preparation

Surface preparation is particularly important when it comes to interior finishes. Surfaces for vinyl pools must be cleaned spotless and free of water before the liner can be installed. Concrete pools must also be clean, structurally sound, dry, and free of form releases (commonly used to build cast-in-place pools), and chemicals that will alter the adhesion of surface materials. Ideally, concrete pools should be floated with an appropriate cement-based patching product to ensure a relatively uniform surface for application of pool interior finishes. Some finishes such as paints, epoxies, and flex-trowel applications require the concrete to be perfectly smooth for application. Any defects in the concrete will be visible through the relatively thin finish materials.
Application methods and maintenance
Application methods rely on following the manufacturer’s instructions, proper training, site conditions, and having the appropriate amount of workers and equipment to complete the job in a timely manner. Many interior finishes, particularly tile, would benefit from tenting or screening the project from the elements.
Most interior pool finish failures are the result of improper surface preparation combined with inadequate application techniques. The combination of poor structure and drainage will also lead to failure. The ongoing variable for all interior finishes is maintenance. Proper water chemistry and care will result in all interior finishes lasting for their intended duration.
Finishing options for pool interiors
Swimming pool interiors can be finished using any one (or more) of a variety of materials. Some of the more popular include:
Clay

The interior of a natural pool is constructed using the available local resources, including clay-based ponds and the extension of rivers into communal swimming holes. Low-cost construction and maintenance are the main benefits of these types of ‘pools.’
Pond liners
A more advanced variation of the natural pool can be constructed using various types of flexible membranes, or even a complete concrete structure to make them waterproof, while natural plants serve as the filter. The longevity of the interior finish for these pools is highly dependent on the construction methods used and the prevailing site conditions.
Vinyl liners

Vinyl swimming pools have been common since the 1960s. Depending on product quality and proper water maintenance, some vinyl liners can fade and degrade in as little as a few years. Generally speaking, however, liners typically last up to 10 years. The advent of interior steps and tanning ledges has stretched the performance of the vinyl liner as these particular design elements can be difficult to install, often requiring on-site welding. For low to mid-range consumers, vinyl still remains the pool interior of choice.
Metal
Swimming pools built entirely of stainless steel are rare, but will certainly stand the test of time. Surface finishes include bare stainless, copper, and full-tile applications. Pools on board ships are often constructed of steel, aluminium, or stainless.
Concrete
There are a variety of options when it comes to concrete pool interiors. Deciding factors include the consumer’s budget and personal choice as well as local conditions. With concrete pool interior finishes the consumer generally gets what they pay for. Exceptions include overpriced plaster and exotic finishes in areas with little competition as prices are highly variable depending on the geographic area of the installation. For instance, areas that have a limited number of installers as well as limited product availability are often priced higher.