An inexpensive option to thick concrete floors. The diagram below is from the 1972 book “The Owner Built Home”, by Ken Kern. In this discussion Kern describes a lightweight 1″ thick fiber reinforced floor system that had been tested extensively in India. The system starts with a flat earthen floor surface that has been loosened to encourage future settlement. Over this soil is laid a thin layer of sand and then the fiber reinforcing. Traditionally this is hessian, a type of burlap. CountryPlans administrator Glenn Kangiser has built floors such as this using jute and landscape fiber mats. The structural bearing of the floor comes from plunger pile footings punched into the soil on a 3′ by 3′ grid with a crowbar or metal rod. These are filled with grout or concrete which melds with the fiber reinforced concrete shell above. After a few weeks the soil below the concrete shell settles and provides a thermal and moisture break from the soil below.
Source: Country Plans.com