An 18×10 Rapidfit Spacious Shed Foundation. Establish a foundation for a backyard structure using the EcoBase Rapidfit Base Kit. Serving as an eco-conscious option compared to pavement tiles or moist-mix concrete, the Ecobase Rapidfit consists of reused matrices that link together to furnish you with a sturdy, robust, enduring, and properly-drained base for your garden structure. 18×10 Rapidfit Spacious Shed Foundation