Grading timber

Abstract

In the past craft and guild workers bought timber or standing trees locally and the quality required was based on carefully circumscribed tradition and local experience. This applied at the cutting edge of technology: to the building of cathedrals during the Middle Ages, to ship building from the sixteenth to nineteenth century, and to the railroads of America, especially to the art of bridge building, in the late nineteenth century. The guilds sought to exclude new materials, such as cast iron and reinforced concrete, on the grounds that they lacked a history of acceptable use. These newer materials were accepted only when it had been demonstrated that their properties were adequate. However, once they were proven, timber found itself at a disadvantage and had to do the same in order to retain a share of the market.