Gravel helps keep the floor level and prevents moisture from seeping up. The floor installers are Jean Pierre (left), a mason, and Daniel Shenyi, operations manager for EarthEnable. Courtesy of EarthEnable hide caption toggle caption Courtesy of EarthEnable Goats and Soda When A Home Poses Health Risks, The Floor May Be The Culprit September 2, 2014 Homes with dirt floors can make people sick. Replacing them with concrete floors helps cut risks but isn't always affordable. A new project in Rwanda relies on a low-cost alternative.