Hi Michelle,
The flooring and base type used will vary depending on the application of the customer. These sheds do not include a floor because of all of the possibilities available. If you are building a solid wooden or concrete platform, that can be used as a floor or base on its own. If installing your shed on level ground we do offer a Floor Frame Kit which will provide support for a plywood floor and in this case you will not require a base. To discuss your options further please feel free to call us at 1-800-851-1085 (press 1). Thank you
https://www.shelterlogic.com/shop/manufacturer/arrow-storage-products/accessories/floor-kits