Particularly for larger glulam structures, it should be checked as to which strength class and surface quality is actually required. Because the yield of lamellas of a higher strength-class is limited even with machine-strength-grading, the fewest possible homogenous glulam members of higher strength-classes should be specified. Large structures of glulam of strength class BS18 also make little sense from an economic perspective. The use of high strength glulam should remain limited to members subjected to heavy loads.
The same applies to the selection of the surface quality. Because the yield of lamellas having of high surface-quality is limited, the adequate surface quality should also be regularly selected in consideration of the subsequent distance between the member and the observer, the lighting and use.
