Knell Construction has revolutionized the lightweight gypsum concrete flooring industry. We were the first to introduce Hacker Industries Firm-Fill Gypsum Concrete flooring to Utah, Idaho and Wyoming. We've been at the forefront of this industry since the beginning and are proud that this advancement is now worldwide. Our gypsum concrete is widely used in the construction of apartments, hotels, townhouses, radiant heat applications for custom homes and other multiple-storied structures where the need for a firm, fire-resistant, soundproofed floor is required.