J.H. Cockerell Consulting Engineers

Applied Pool Finishes

Tiles

Tiles arguably provide the best quality of any finish commonly applied to the concrete shells of municipal and school swimming pools.

If tiles are well chosen, well detailed and correctly installed they can provide the cheapest whole life cost for an applied finish to a pool that has a design life of 50 years. However if tiles are not well chosen and not well detailed and not correctly installed, they can provide the most expensive whole life cost for the finish of any pool. A well tiled pool always looks attractive, and is easy to keep clean, enhancing pool water quality.

Cement Based Renders

Cement based finishes are a mixture of sand, cement and other additives. They provide a rougher finish than tiles.

Cement based, applied pool finishes have considerable limitations, including the following:-

  • The pool cannot be emptied for maintenance without considerably increasing the risk of some areas of the applied finish delaminating from the pool’s concrete shell. When the applied finish delaminates (i.e. detaches and is “drummy” when tapped), growths of algae and bacteria develop unnoticed in the void created, compromising pool water quality.
  • The cementitous material provides an ideal rough surface for the attachment of algae. The use of granulated chlorine and brooming to remove the algae make the surface even rougher. This cycle of algae growth and removal makes algae removal more difficult each time. It is only a matter of time until the applied finish must be removed and replaced. This is an expensive exercise.
  • Cement based renders crack due to differential movement between the render and the pool’s concrete shell. Render beside cracks often becomes drummy allowing the growth of algae and bacteria in the void created.

PVC Liners

PVC liners are typically approximately 1mm thick and therefore very susceptible to damage, particularly from vandalism. PVC liners are usually used in pools that have not been designed to be water-tight. As a result, when the liner is damaged, the pool is obviously no longer water-tight. For these reasons, PVC liners are seldom used as a finish for municipal and school swimming pools.

Paint

Chlorinated pool water is an aggressive environment for any painted surface. As a result, painted pools require regular repainting. Eventually numerous layers of paint make repainting an ineffective solution, necessitating removal of paint back to bare concrete. The paint removal process often leaves the concrete too rough for repainting. The only solution is to skim coat the concrete before repainting.

Chlorinated rubber based paints

For a long time, chlorinated rubber based paints have been used to paint the internal surfaces of large concrete pools. At best, chlorinated rubber based paints only last a couple of years before they require repainting. Poor surface preparation or incorrect application of chlorinated rubber based paints often results in the paint lasting only a few months. Painted pool surfaces in poor condition make a pool unattractive to bathers. Oxidation of chlorinated rubber based paints creates a loose powder on the painted surface. When the surface is rubbed, the oxide becomes suspended in the pool’s water, compromising pool water quality.

Epoxy Paints

More recently, epoxy paints have been used, instead of chlorinated rubber based paints, to paint pools. Epoxy paints, if correctly applied, can provide a painted pool finish with a longer life than chlorinated rubber based paints. Epoxy paints require careful application to achieve a good bond to the concrete substrate and between layers of epoxy.