Quality of air-dried paulownia lumber

Lumber sawn from 10- to 14-year-old paulownia trees was studied to determine quality after air-drying as indicated by defect development and air-drying rate. It was found that this naturalized species dries easily and rapidly without serious drying defects. Commencing May 20 in eastern Kentucky, the drying time from green to 20 percent moisture content (MC) was 39 days, or 3.5 percent MC loss per day. Paulownia is dimensionally stable with an average volumetric shrinkage (green to ovendry) of 5.9 percent, a value lower than any native, commercial hardwood. Lumber was primarily flatsawn to maximize defect development during drying. End splitting was the major drying defect and was commonly associated with pith that was large compared to native hardwoods.