One-sided concrete applications. where only one side of the formwork is installed, can benefit greatly from shotcrete. With this method, up to 95% to 100% of the required formwork can be eliminated, leaving only construction joints and perimeters to be framed. Shotcrete also eliminates the need to engineer the forms, as there are no internal pressures from the fresh concrete. However, for double-sided walls, a rigid back form or stay form must be used in conjunction with shotcrete