As our Forma composite decking is made of plastic and wood fibres with a protective layer over it, there is no need to sand the boards. If you try to sand composite decking, the surface layer may become damaged and expose the composites underneath. Instead of sanding composite decking, consider protecting your deck with a mat or simply replacing any badly damaged boards. Our Clarity composite decking range can be sanded as the material is the same all the way through. This is especially useful if the Clarity decking has stubborn marks.