Abstract: A trailer system to accommodate the construction and transport of a mobile home or RV comprises a tie down and flooring system to increase the useable vertical space of the attached structure. Two main deck frame members 200 are placed in parallel and are secured together by several Z bar floor joists 400. The lower surfaces of the Z bar floor joists retain a lower pan or galvanized sheet steel plate 300, the steel plate used to protect the undercarriage of the trailer. A tie down assembly comprises several threaded rods attached to the outside vertical surfaces 201 of the two main deck frame members. A sill plate 520 and tie down unit 110 are placed through the threaded rods to provide a low profile tie down system.