Vermiculite vs. Grout Vinyl Liner Pool Bottom: Which Is ...
Grout is a form of concrete made of sand, cement, and water. It's usually brought to the pool site in a ready-mix concrete truck. The grout pours out a chute into your pool-shaped hole in the ground. Pros. It provides more compressible strength than vermiculite (2000 psi or more compared to 100 psi). Grout is creamier than vermiculite.