| RP, C36, Cororib, Utility Rib, U230, BR and SS18 are suitable for use as exposed roof panels. Side laps of all patterns should be continuously caulked on slopes less than 60 degrees and at potential snow drift points. Exposed screw fasteners should have neoprene sealing washers. Continuous sheet lengths greater than 60' should be avoided on enclosed insulated buildings because of thermal movement. RP panels are listed in U.L. construction 30 and 79 for class 90 wind uplift.
The roofing load tables show allowable total uniform loads based on gravity loading. Wind loading, because of the allowable 1/3 stress increase, will generally show higher loads. Wind loading, as a suction force, can also cause deflection loads different than those shown in the load table. Use the appropriate I value to calculate the upward deflection of the exposed panel or refer to the appropriate wind loading tables on the previous pages.
During the erection of exposed roof panels it is often advisable to plank or otherwise protect the material from abrasion and damage caused by workmen. The maximum unplanked spans shown in the table are based on a 200 pound concentrated load; stress is limited to 26600 psi and deflection to L/120. A lower limit of 30" has been applied to match a stride. A conscientious erector may extend or reduce these spans based on his experience.
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