Our timber engineering heritage – Design notes for plywood folded plate roofs

The folded-plate roof has become a familiar feature of contemporary architecture. The original folded-p1ate structureswere built in concrete, but plywood has been used successfully for this purpose since about 1954. The lack of data onNew Zealand made plywood has restricted the progress of plywood folded-plate design in this country; but, with theimpending publication of industry standards for structural-grade plywood manufactured specifically for use in highlystressed structures, further development is now feasible. It should be noted that the ordinary interior and exteriorgrades of plywood are not designed .for structural use; such grades are built for appearance, and the strengthcharacteristics are largely uncontrolled.Folded-plate roofs add to the architectural value of a building, and in addition have economic advantages: large areas ofcolumn-free space are possible; roof overhangs may be cantilevered out to form veranda roofs. When built in plywood, afolding plate is a light but stiff form of roofing capable of carrying all normal roof Ioads.