There is no question or argument to the statement that concrete pools are the most custom. You may have also heard them referred to as gunite pools, shotcrete pools, or plaster pools.
Some pool styles can only be done with a plaster pool. For example, in-ground vinyl and fiberglass pools are not designed to enable a traditional vanishing edge. Some manufacturers are beginning to experiment with these designs, but they are extremely limited in what they can do, and they don’t look like a traditional vanishing edge.
A gunite pool enables customization of every part of the pool. Not only can you customize your pool with your choice of tile and plaster, but you can also customize the shape and depth of the floor, design and position of the steps, and design and position of benches and ledges.
For your high-end pools with designs like vanishing edge (infinity), perimeter overflow (rim flow), dual-level, and pools with custom faux rock walls and grottos, a plaster pool is the only real option. Be very careful if someone tries to tell you otherwise; be sure to get additional opinions.
Between fiberglass and in-ground vinyl, some feel that vinyl is the most customizable. The floor and design and position of the steps and benches is more customizable, but the finish of a fiberglass pool is more customizable in the selection of tile and finishes. There are more vinyl patterns than fiberglass pool finishes, but the fiberglass pool finishes have a much more custom and high-end appearance. Vinyl pools are almost never made with tile beneath the coping, whereas tile is a standard offering for fiberglass pools.
Given that concrete pools are the most customizable, are there draw backs? In the Treasure Valley, there are durability issues with these pools due to the freeze/thaw conditions we experience. In places without freeze/thaw considerations, this factor would not be a consideration. The most common durability issue occurs with the tile, which is installed with grout. Over time, grout can develop micro-cracks, which are not defects but a natural condition of weathering grout, allowing water to slowly seep behind the tile. When the temperatures drop below freezing that water expands and pops the tile. A similar condition happens with pebble products used for the “plaster”. The freeze/thaw can cause pebbles to break away from the surface leaving unsightly voids.
Despite the durability question, if you want a vanishing edge pool, perimeter overflow pool, dual-level pool, or a different very custom pool, the only real option is a gunite/shotcrete/plaster pool.