Easily fasten HardieBacker or equivalent fiber cement backerboard with Backer-On Star Head Cement Board Screws. Our patented serrated head design countersinks for flush, smooth tiling at any angle. Climacoat provides rust-resistant protection in high-moisture areas, and installation is a breeze - no need for extra tools - with a standard impact or drill/driver and included T-25 bit. Let Backer-On make your tiling job easy!