Is polyurethane foam the only material used for void filling?

Polyurethane foam is the most common material for residential and commercial void filling because of its water-resistance, lightweight properties, and fast cure time. For very large voids in heavy industrial or municipal applications cementitious grout is sometimes used for its higher compressive strength and lower material cost per cubic foot. Scaldino selects the fill material based on void size, expected load, and site conditions.