Old oak planks which are already 100 to 300 years old may have some shakes of course. Different oak colours emphasize the natural patina of the old wood. Due to the atmospheric environment the planks may curve a bit or dwindle. This is not a reason for rejection. Old wood may naturally contain knotholes, small pitch pockets, isolated fillings or smaller cracks. Fillings, defects, smaller holes and cracks might have to be professionally refilled or repaired after installation.