An evaluation of the saw, dry and rip process to convert red alder into studs

The conversion of red alder (Alnus rubra Bong.) into structural lumber using the Saw-Dry-Rip (SDR) process was analyzed by comparing product yield and quality from conventional and SDR conversion processes and from conventional and high temperature drying schedules. A limited economic assessment was also made. It was found that conventionally processed studs had 53% rejects due to warp which was reduced to 6.1% by using the SDR process and high temperature drying. Site had a significant effect on degree of warp. Based on qualities other than warp, 91% of all studs produced met the STUD grade. No difference was found between the strength related properties of high-temperature and conventionally dried material. Excluding material and processing costs, the product value of the SDR processed material was increased 26.6% over conventionally processed material.