This placed on them a load of more than 20 pounds per square foot. The roofs of some houses were estimated to have been under more than 460,000 pounds of snow and ice. Little wonder that many collapsed. John Langston, an ag engineer with the University of Arkansas Extension Service, says poultry houses can be made stronger to hold up against all but the very strongest storms. He notes that most poultry houses are built with metal rigid frames.
Clear spans allow easy clean-out.
Failures can occur, however, if the frames are too lightly constructed, spaced too far apart or improperly aligned. Frames can be weakened if too few alignment braces are used to keep the bottom chord in line with the top chord. The metal rigid frame is a three-hinged structure that has a hinge at the ridge and others at each of the two foundation points. The frame must remain rigid at the eaves. All loads on the roof are transferred through the rigid frame to the foundation and footing.