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Cost of Wood and Concrete Compared^k 



One of tbe topics discussed at the meeting of the Forest Products 

 Federation in Chicago in February was the comparative prices of 

 building materials, and a paper presented by J. Xorman Jensen, an 

 architectural engineer of Chicago, handled in an instructive way the 

 comparative cost of certain types of buildings built of wood and of 

 concrete. A general comparison applicable to all sizes and patterns 

 of buildings was not attempted, because it was deemed impracticable 

 to deal with the subject in so general a way. Comparisons were con- 

 fined to two types of buildings, factories and small residences. Fig- 

 ures were taken from actual building operations in Chicago, and the 

 showings are actual, not imaginary. These figures cannot fail to 

 encourage lumber dealers who have feared that they would not be 

 able to compete much longer with substitute building materials. 



Mill Construction 



Much lumber is used in the erection of mill constructed buildings. 

 By "mUI construction" is meant that type of construction in which 

 every beam and girder is not less than 6"sl2", every post not less 

 than 10"slO", all floors at least 31V', and all roofs at least 2%" thick. 



The advantages of a wooden factory over one of concrete, so far 

 as comfort, convenience, and freedom from injurious dust are con- 

 cerned, are passed over in the present discussion, and cost alone is 

 considered. 



Perhaps the best way to compare costs is to mention a number of 

 actual bids on completed structures. In a certain large architect's 

 office a design was prepared of a building which was to be erected in 

 an old manufacturing district in Chicago. The building was five 

 stories and basement high, 100x100 feet, and designed for 280 pounds 

 live load. The panels in the standard mill design were 14x16 feet, 

 and brick bearing walls were used throughout. The concrete building 

 of the same height and size was designed in the most economical 

 type of flat slab concrete skeleton construction. The actual bid for 

 the mill constructed building was .$65,100, and for the concrete type 

 $72,200. 



Another building was seven stories and basement high, 68x7.5 feet, 

 and designed for 150 pounds live load. The panels in both designs 

 in this case were 18x16 feet. The mill constructed building cost 

 $65,400, and the concrete building $75,300. 



If wood floors had been required in these buildings, the difference 

 between the mill and the concrete prices would have been greater than 

 ever. 



The live load mentioned is the load per square foot which can be 

 safely put on top of the floor. This live load is usually the weight of 

 machinery, or goods placed on the floor. For most light manufactur- 

 ing buildings a live load of 100 pounds per square foot is sufficient, 

 and for 75 per cent of the buildings used for storage purposes 200 

 pounds per square foot is all that will ever be placed on the floors. 

 So the column spacing and the loads cover most all the cases which 

 may arise. 



Another point which determines the adoption of mill constructed 

 building in preference to concrete is the fact that in ordinary lines of 

 business the rate of insurance on a sprinkled mill constructed build- 

 ing and contents runs about twenty-five cents, while the rate on a 

 concrete building and contents, unsprinkled, runs about forty-five 

 cents. The rate on both types of construction, sprinkled, is about 

 the same, but the cost of installing the sprinkler system in the con- 

 crete building makes the total cost still higher in comparison with a 

 mill building. A concrete building in which wooden floors are used 

 cannot compete with mill construction. 



With column spacings not exceeding sixteen feet, mUI constructed 

 buildings designed for 100 pounds live load cost twenty per cent less 

 than concrete buildings; for 150 pounds live load fifteen per cent 

 less ; and 200 pounds live load, about ten per cent less. When the live 

 load exceeds 350 pounds, the concrete building is cheaper. 

 Comparative Costs op EEsroENCEs 



It is an extremely difficult matter to give comparative costs between 

 residences which are built of frame construction and those built of 



—14— 



other types. Mill buildings are standard compared with the variation 

 of ideas as to how to build a residence. 



In order to obtain a comparison between the cost of small frame 

 and brick buildings as built in the city of Chicago, an architect pre- 

 pared complete plans and specifications of a number of one and two- 

 story buildings, and obtained bids. These buildings were typical of 

 the low and medium priced cottages and small flats actually built in 

 great numbers in Chicago. The bidders were responsible contractors. 



In each case in which a frame buOding was compared with a simi- 

 lar brick building, the size of rooms, plumbing, trim, interior finish, 

 etc., was identical. In all cases the frame building had a shingle 

 roof, while the brick building was provided with a non-combustible 

 roof. 



The average of the bids on these buildings was as follows: 



Frame. Brick. 



One-story cottage, 22'x30' $1,719 $1,823 



One-story cottage, 20'x36' 2,394 2,684 



One-story cottage. 21'x4S' 3,419 3,906 



Two-story flat, 24'x34' 4,185 4,564 



From these figures it is seen that the cost of the frame building was 

 about ten per cent less than a similar brick building. 



Where Veneers Are Used 



The relative quantities of veneer used by various industries are not 

 shown in available statistics. The total annual production of all 

 thickness is known, and the various thicknesses are segregated in a 

 way to determine how much of each is produced. The amounts cut 

 from various woods are tabulated, and there are separate figures for 

 rotary cut, and sliced, and sawed. Beyond these points the records 

 do not go. 



The person who undertakes to state how much veneer goes to this 

 industry or to that must indulge in guessing, but it is possible to 

 secure much information so that the guesses may be brought within 

 the range of probabilities. It is very commonly believed that furnit- 

 ture manufacturers are the largest users of veneers, and after that, 

 according to popular opinion, come the musical instrument makers and 

 the industry known as fixtures. The most common articles grouped in 

 the fixture industry are store and bank counters, office partitions, 

 and saloon bars. The total annual demand for wood in making fur- 

 niture, including chairs, totals 1,250,000,000 feet, board measure, in 

 the United States. Musical instruments call for 260,000,000 feet, and 

 fixtures account for 187,000,000 feet. In making the articles included 

 in the foregoing classes, there is no fixed ratio between the use of 

 lumber and of veneer. It is certain that veneer lacks much of con- 

 stituting one-fourth of all the wood reported for these three industries, 

 but it is not possible to quote exact figures to show it. 



There is little question that those who have given credit to furni- 

 ture, fixtures, and musical instruments for the largest use of wood 

 veneer, have overlooked the most important of all — the box. The 

 combined use of wood by makers of musical instruments, fixtures, and 

 furniture scarcely amounts to one-third of the demand by box makers. 

 In the manufacture of shipping boxes, veneer is employed in large 

 quantities. Some of the small shipping containers which are made 

 in enormous numbers, are wholly veneer, while many large shipping 

 cases have veneer sides, tops, and bottoms, with reinforced corners. 

 In boxes of that kind, the veneer is usually three ply. The wire-bound 

 box, which is principally of veneer, is in much use. 



Just how thick a sheet of wood must be to pass out of the veneer 

 class and become lumber, may be a subject of controversy. When 

 the government compiles statistics it classes as veneer all lumber five- 

 sixteenths of an inch in thickness and under. More veneer is of 

 three-sixteenths inch thickness than of any other dimension, if all 

 be reduced to a board-foot or a log measurement. About one-fifth 

 of aU veneer cut in the United States is of that thickness. If cal- 

 culated by superficial measure, veneer one-sixteenth inch thick exceeds 

 every other dimension. 



