 The posts were chemically treated to resist decay, greatly increasing the useful life of a building.In the 1950s and 1960s, metal-plate-connected wood trusses were developed, increasing roof spans, eventually up to 100′ (30 m).In the 1970s and 1980s, solid sawn posts were supplemented by laminated 2×6 and 2×8 posts, allowing taller buildings.