Abstract: A prestress floor system for wood floor framing structures places the structure's joists under a laterally directed compressive force while the joists are maintained in their relative positions by blocking elements. The compressive force is provided by a cable anchored at one end to an outermost joist and anchored at the other to a spring that is, in turn, anchored to an outermost joist. The resulting structure has increased vertical stiffness and reduces the amount of deflection, vibration, and noise experienced during loading.