The Effect of Creep on Long Wood Column Design and Performance

Forty 4×4‐in. wood columns were tested to observe the effects of creep on the time-to-failure. Models of column creep based on fundamental beam creep were devised and employed to explain the variability observed in the column behavior and to suggest when and how designers should introduce beam creep effects into design calculations. It was determined that creep would only present problems for extremely high permanent column loading; however, it was also shown that the natural curvature of columns of commercial grade lumber is a more important influence than creep on performance and design for the majority of situations. Methods of introducing creep into analysis, and of estimating variation in column behavior are described.