System Performance of Wood Header Assemblies

This report focuses on the performance of typical wood headers used in conventional residential construction. The primary objective of this test is to investigate the magnitude of system strength enhancement realized by typical header assemblies including the effects of other wall and floor framing members. Headers are built-up dimensional lumber assemblies used as horizontal beams to support loads from wall. roof, and floor areas above window and door openings. Headers are usually made as paire d 2x lumber members. These headers can be quickly and easily designed as simply supported beams using basic principles of engineering mechanics. However, this typical approach results in a conservative design, as it does not consider any system effect. Therefore, a secondary objective of this report is to provide guidance so that system effects can be appropriately considered in the efficient design of conventional wood headers.