Earle B. Norris Research Professor Emeritus of Wood Construction, Virginia Polytechnic Institute and State University, Blacksburg, VA
(Received 27 January 1987; accepted 6 August 1987)
Building codes and agency regulations concerning permanent railing systems and rails for buildings cover the required resistance of these building elements to potential forces and disregard their deflections. This is the case despite the fact that deflections and residual deflections may govern the performance of railings and rails according to recent test data established by the American Society of Civil Engineers' Task Group on Pre-Standardization of Permanent Railing Systems and Rails for Buildings. The updating of building codes and agency regulations with the inclusion of deflection criteria is appropriate.
Reference data were obtained based on the application of vertical and horizontal static loads to 60 steel, aluminum, red-brass, yellow-brass, and stainless steel picket, panel, and pipe railing systems and rails of various designs. These data indicate that design loads of, say, 900 N (200 lbf) applied horizontally at the centers of railing systems of two 1.50-m (5-ft) spans may, under given conditions, be resisted only at deflections ranging from 65 to 125 mm (2 1/2 to 5 in.). On the other hand, a lesser deflection may be required under certain conditions because of the psychological aspects involved. Those railing systems which did not meet the 900-N (200-lbf) design-load requirements at acceptable deflections might be remedied by the use of inserts in the pipe and tubular posts or the use of stronger posts.
Paper ID: JTE11164J