Structures in which treated material should be used-Continued It is not essential that all lumber used in residential structures be treated. Attention is called to the discussion on p. 21. WOOD PRESERVATION AND THE HOME OWNER The acquisition of a home is in most instances the most important investment which the average citizen undertakes. Generally home ownership depends on the securing of a loan, and the terms of this loan are based largely on the value represented by the house. It is therefore evident that the home owner must not only consider the question of good design, plan, and construction, but he must also check up on the quality of the building materials used, because the life of the house is in direct proportion to the life of the materials employed. The best construction methods will not prevent premature depreciation if good building materials have not been employed. There are certain vital parts of a wooden structure which are particularly subject to decay and insect attack. If the home owner will insist on protecting his interests by using treated wood for the construction of such parts he will undoubtedly find this fact taken into consideration by the banker who grants the loan. The use of preserved wood will therefore contribute to the increase in individual home ownership. Certain trends of modern architecture favor setting the house as close to the ground as possible. (Frontispiece.) In such cases preserved wood may be used to advantage wherever wood is used in direct contact with the ground. In many cases home owners are desirous of remodeling their houses and thus an opportunity for the use of treated lumber may be offered. The aim of the National Committee on Wood Utiliza tion is to interest the small consumer in the use of preserved wood to protect his investment. If larger consumers of preserved wood, such as railroads and public utilities, have been able to effect appreciable economy through its use, it is reasonable to expect that proportionally greater savings will accrue to the smaller consumers, on whom the burden of repair and premature depreciation rests more heavily. For this reason the National Committee on Wood Utilization is sponsoring the retail distribution of treated lumber, to make it available to the average lumber consumer. THE BUILDERS' INTEREST IN WOOD PRESERVATION Architects, engineers, and builders interested in furthering good construction practices will find that the use of preserved wood represents an appreciable economy. They should bear in mind that it is cheaper to prevent decay than to repair or replace decayed lumber. In determining the life of a building or a structure, and their obsolescence, it will often be found that the cost of the use of preserved wood will represent an appreciable economy as compared with the cost of using the more expensive and more permanent building materials, which might otherwise be considered. It is important to have in mind that wood always kept in a dry condition will not decay. It is therefore important to control the moisture content in wood if untreated. However, where this is impracticable, properly treated wood may be used to advantage. In most instances it would not be economical or desirable to use preserved wood for all the wooden members of the house. Wherever untreated wood is used it is of vital importance to minimize the danger of decay through providing for the proper circulation of air, particularly in attics and other places where high humidity sometimes prevails. Particular attention should be paid to avoiding the use of unseasoned building materials where decay may later on develop. Even though lumber is kiln dried (thus killing wood-destroying organisms) new infestations may develop later, if conditions are favorable. There may develop in structures, some time or other, leaky roofs and walls, worn-out rain spouts, or defective plumbing, all of which may aid in carrying wood-destroying organisms to reinfest wood. Construction and installations of windows, doors, and trim should be carefully safeguarded, as these points are also susceptible to leakage. Any conditions which favor decay should be avoided, especially in basements or cellars below the ground line, by making sure that construction details assure good drainage, minimize excessive moisture, eliminate leakage, etc. In every instance foundation wall plates and joists in wood structures in close contact with the ground should be treated. Likewise sleepers and wood basement floors, or laminated floors laid on the ground, should be of treated materials. It has been determined that, unless space is allowed to permit air circulation around girders, joists, and stringers embedded in stone, concrete, or brick, they should also be of chemically preserved wood. This refers particularly to heavy timber construction. In short, the use of preserved wood materially lengthens the life of any structure, if used in places where the wood is exposed to decay and insect attack. THE LUMBERMAN'S INTEREST IN WOOD PRESERVATION It is evident that if lumber as a building material is to retain its popularity efforts must be directed toward increasing its usefulness to the ultimate consumer. Through the application of wood preservatives to wood the principal handicaps of this material, namely decay and depreciation through insect attack, may be overcome. In the past a considerable market has been lost to forest products for purposes where the use of treated wood would have been both desirable and economical. In many instances the present FIGURE 13.-Laying the creosoted subfloor over creosoted sleepers, on top of which is laid the top flooring. Courtesy American Wood Preservers' Association question is whether to use treated wood or dispense with wood altogether, and the progressive lumber manufacturer, as well as the lumber wholesaler and retailer, has realized the importance of wood preservation as an aid in the maintenance and expansion of their markets. Wood preservation is therefore a step in the direction of giving the consumer better value for his dollar, a step to which every producer of building material in modern times is forced as a result of competitive conditions. The National Committee on Wood Utilization, in sponsoring the retail distribution of treated lumber, is fully aware of the fact that many difficulties may arise, particularly in the carrying of a full line of all of the sizes of treated lumber used in building and construction. The following is a list of sizes which Ohio retail lumber dealers are stocking in cooperation with the committee's project. It represents those sizes which experience indicates are in greatest demand. Treated lumber carried in stock PRESSURE TREATMENT ZINC CHLORIDE OR CREOSOTE 14 ft. lengths 2 x 6 2 x 6 2 x 6 2 x 6 2 x 8 2 x 8 16 ft. lengths 6/4 6/4 -- No. 1 Com. S4S Std. Y. P. Rough No. 1 Com. Y. P. PRESSURE TREATMENT ZINC CHLORIDE ONLY No. 2 Shop Rough-Pondosa or Calif. Pine. However, it would undoubtedly be wise for retailers to concentrate at first on the dimensions most in demand, and later to expand their stock lists sufficiently to take care of the demand for various sizes. As such demand gradually develops, with the continued progress in standardization of lumber sizes and grades all through the country, the chances for the handling of preserved wood will correspondingly improve. The retail lumberman should pay particular attention to proper handling methods, as described in this report. It is also of importance that he should check up on his supplies so as to insure receiving properly treated lumber. There is danger of destroying the market for preserved wood by forcing on the consumer improperly treated stock, which will not render proper service in the particular use for which it is intended. WHERE PRESERVED WOOD CAN BE OBTAINED The only method by which properly treated lumber can be made available to the millions of small users is through the retail lumber dealers. This is a field which retail lumbermen should find very fertile. Some have already entered it, and others should be encouraged to do so. Heretofore the wants of the large industrial users have been filled either by commercial wood-preserving plants or by plants of their own; but it has not been economically practicable for the individual small user, in most cases at considerable distance from a treating plant, to obtain the few hundred feet he would like to have to give his buildings the permanence they should have. Through arrangements recently completed, however, certain retail lumber dealers have obtained standard treated lumber in quantity from the treating plants and can furnish the individual user with the quantities he may desire of the most commonly used sizes. This is a desirable field of activity that lumber dealers in every section of the country should investigate, and an extensive campaign to promote the retail distribution of treated lumber is being sponsored by the National Committee on Wood Utilization. INFORMATION ON WOOD PRESERVATION Wood preservation is a definite art, and the processes developed are the result of long study and research. The efficient and definite results obtained by wood preservation are responsible for the satisfactory growth of this branch of industry. The National Committee on Wood Utilization is interested in giving the nontechnical consumers only such information on the subject of treated lumber as will lead to the most economical results, based on long experience. It knows that the small consumer can ill afford to experiment with new and untried processes and that this field of experimentation should be left to the larger consumers who are in a better position to follow developments in this line. Such technical problems as have arisen in preservation work have been handled by the United States Forest Products Laboratory, at Madison, Wis., the Bureau of Entomology of the United States Department of Agriculture, Washington, D. C., and the American Wood Preservers' Association, at Chicago, Ill. The Forest Products Laboratory is a branch of the United States Forest Service, and was established in 1910 for the study of the physical and mechanical properties of wood, its chemistry and pathology, and its manufacture, conversion, and use. The purpose behind the accumulation of knowledge resulting from these studies is the same as the whole purpose of the Forest Service, namely, the maintenance-by growth or conservation-of an adequate timber supply. Its wood preservation section is organized to develop preservatives, wood impregnating methods, and sanitary measures, to cut down the largest single item of preventable waste that occurs in timber production and use; that is, the destruction of wood by decay. A large part of the work of the section of wood preservation is performed on railroad ties, because they are convenient to work with and give results for general application, and because the test is a severe one where the wood is in close contact with the earth and is exposed to decay and insect attack constantly. Test installations and service |