Please note that this is a scanned copy of a paper originally published in 1990, so the text is not as clear as in documents created as pdf files (you may need to enlarge sections or adjust contrast when printing).

Timbers at risk from attack by wood-destroying organisms need effective preservative treatments. Commercial hem-fir varies greatly in its treatability; this presents difficulties in specifying a single schedule that will adequately treat all components in a charge.  

This paper presents the results of an investigation into the preservative treatment of joinery-grade and construction-grade hem-fir using high-pressure and double vacuum treatment schedules. 4 pages.