Shrinking and Swelling of Wood in Use. Information Reviewed and Affirmed.

摘要

Wood normally shrinks as it dries and swells as it absorbs moisture. These changes in its dimensions are of importance to anyone who uses wood, whether for tanks or toys, shoe lasts or ships, because wood readily takes on or gives off moisture, even from the atmosphere. Successful use of wood for exacting purposes under wide variations in atmospheric humidity shows that the problems arising from the shrinking and swelling of wood can be surmounted. Good practice, in general, requires that efforts be made to reduce the changes in dimensions that take place while wood is in use and to minimize their effects by methods of installation and construction. Fortunately, wood is somewhat plastic, so that it can conform to a certain amount of dimensional changes without serious damage. On the other hand, the stresses developed in shrinking or swelling may cause a great deal of damage.