A NATIONAL PLAN FOR AMERICAN FORESTRY 1367 



BETTER USE OF WOOD IN CONSTRUCTION AND FABRICATION 



Research must show the way to radical improvements in wood con- 

 struction. The convenience, low cost, and other advantages of wood 

 must be combined with simplified, efficient, and cheap design and 

 erection, and better preparation and maintenance of the material, to 

 produce more durable and economical structures. Wood has lost 

 ground competitively because of insufficient technical progress in its 

 use. Since more than 60 percent of the lumber produced in the 

 United States is used in the construction of buildings, it is especially 

 important that this market be retained and expanded. Intensive 

 research vigorously prosecuted offers the only practical way to keep 

 wood abreast of the continuous technical progress being made by its 

 competitors and thus to avoid unnecessary substitution of com- 

 petitive materials for wood. 



UNIT CONSTRUCTION 



Wooden houses cost too much. Present designs and methods of 

 building coupled with the normal tendency toward higher wages and 

 shorter hours have reacted to discourage building. The obvious 

 answer is mass production of wood units that can be assembled 

 quickly and inexpensively, in line with similar developments that are 

 occurring in steel and concrete housing. The progress that has been 

 made thus far is entirely inadequate. 



Research therefore has an urgent practical objective in seeking to 

 develop practical forms of wooden-unit construction for dwellings and 

 larger buildings. Full-scale tests of special forms of wall, floor, and 

 roof units should be made. One type of material that offers itself 

 for use in large units is plywood. Ready-made plywood wall sections 

 embodying self-contained insulation may prove an economical and 

 satisfactory replacement for the present composite wall of wood and 

 plaster. The development of such untis involves several phases of 

 research practical and efficient design; tests for strength and weather 

 resistance; the production of a cheap, permanent, water-resistant 

 glue; and of sightly, weather-tight joints. Another possibility is the 

 development of built-up lumber units of an interlocking type. In any 

 kind of unit construction, the design of the structure as a whole 

 requires adequate architectural study to insure acceptable variety, 

 appearance, and convenience. 



ENGINEERING RESEARCH 



Great improvements in building construction can be made without 

 waiting for the development of mass production. Built-up wooden 

 columns and glued laminated arches and beams should replace much 

 expensive solid timber. They permit better selection of the wood for 

 quality, favor refinement in design, conserve the large sizes of timber, 

 arid make possible the utilization of smaller, cheaper units of lumber. 

 Laminated wooden arches are especially suitable in the construction 

 of halls, hangars, and other buildings of large open span and are 

 finding extended use in Europe. They need thorough testing and 

 adaptation to American use. The Forest Products Laboratory has 

 investigated the problem of the built-up column and determined a 



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