The Simpson Strong-Tie. Strong-Rod uplift restraint system for roofs (Strong-Rod URS) is a continuous rod tiedown solution designed to provide a complete load path to resist uplift (suction) pressure on the roof by transferring these forces through the structure to the resisting elements (typically the foundation). Designing rod systems to resist wind uplift (URS) is very different from designing rod systems used to resist shearwall overturning caused by lateral wind pressure or seismic forces (ATS). This is due to where each type of force originates in a building. For wind uplift, this is only at the roof and can be reduced by dead load at each level of the building. Lateral forces are applied at each level (each horizontal diaphragm, both roof and floor) of the building, and increase at each lower level as load from the level above is added to the level below.