Vermiculite is a naturally occurring product used as a base material in swimming pools to help form and support for pool liners.
What is Vermiculite for swimming pools?
Vermiculite is a naturally-occurring phyllosilicate, or sheet silicate mineral. Its distinguishing characteristic is that it is scaly, platy, or flaky, although it also is similar to that of a thick, aggregate clay. When exposed to heat, the crystal structures cleave, causing the material to exfoliate, or flake off from the surrounding material. Many commercial products are made with vermiculite, such as pre-molded structures, calcium silicate boards, machine brake liners, no-soil planter medium, seed germination packages, packing materials, and soil conditioners.
For swimming pools, vermiculite is commonly used as a base in swimming pools to create a smooth, even surface foundation for the walls and floor, which then a vinyl liner is then affixed. High-quality vermiculite grades are combined with Portland cement that are either pre-mixed, or mixed at the pool site through a cement mixer, and is often the preferred choice as a base for vinyl-lined swimming pools.
- Wikipedia, Vermiculite.