Shrinkage and overmeasure of fir-wood boards

Investigations carried out aimed to establish the relationship between shrinkage of fir-wood determined on the basis of small lab tests (3 x 3 x 2 cms) and shrinkage determined on the boards (thickness 25, 38, 48 and 76 mm, width 110 mm, length 1500 mm). Fir-wood from two areas of different height above sea-level has been examined. The results show that shrinkage on the basis of average literary data or on the basis of shrinkage of small tests of homogenous material could be taken conditionally as sufficiently accurate for determination of overmeasure. When determining the overmeasure the standard deviation should be known for it has an influence on the accuracy of determining the overmeasure. Shrinkages in width are somewhat smaller than shrinkages in thickness. The elements for determining the overmeasure at thickness are satsifactory, so at width, as well. From the graphs attached it is possible to determine the overmeasure for thickness, i. e. the moisture which has not been included into this examination.