Aging effects on physical and mechanical properties of spruce, fir and oak wood

Various aspects of natural aging on wood, such as the physical and mechanical property changes as well as colour changes, were investigated on wood of Norway spruce, silver fir and European oak. Thereby, aged wood from several historical or old, deconstructed buildings were compared with recent wood samples. It could be shown that aging modifies wood colour and causes a reduction of impact bending strength, whereas sorption and swelling as well as bending and fracture toughness do not, or only partly, show a modification over extended time.