The cost of labor per cubic yard was:
| Forms, per cu. yd. | $1.900 |
| Mixing, per cu. yd. | 0.210 |
| Placing, per cu. yd. | 0.310 |
| Finishing, per cu. yd. | 0.143 |
| Handling cement, per cu. yd. | 0.017 |
| Handling sand, per cu. yd. | 0.104 |
| Handling steel, per cu. yd. | 0.270 |
| Handling aggregate, per cu. yd. | 0.222 |
| Coal, at $4.25 per ton, per cu. yd. | 0.010 |
| Foreman, per cu. yd. | 0.133 |
| Teams and laying pipe line, per cu. yd. | 0.087 |
| ——— | |
| Total, per cu. yd. | $3.406 |
Summarizing, we have the following cost per cubic yard:
| Concrete materials, per cu. yd. | $2.76 |
| Labor mixing and placing concrete | 1.01 |
| Forms, materials and labor | 3.64 |
| Reinforcement, materials and labor | 1.42 |
| Fuel, foreman and pipe line labor | 0.23 |
| —— | |
| Total, per cu. yd. | $9.06 |
The cost for handling steel, making stirrups, welding, etc., was $8.90 per ton, or 0.45 ct. per lb.
CONSTRUCTING WALL COLUMNS FOR A ONE-STORY MACHINE SHOP.—The building was 53×600 ft.; each side wall consisted of 40 columns of channel section carried on footings of channel section somewhat heavier than that of the column. The columns were spaced 15 ft. on centers and each was 7½ ft. wide so that there were 7½ ft. spaces between columns, which were filled with 3-in. curtain walls extending 7½ ft. above the floor. Figures 228 and 229 show the column and footing construction. Each column contained 125 cu. ft., or 4.63 cu. yds. of 1-3-5 1-in. crushed slag concrete above the footing and the costs given here relate only to the columns above footings. In the 80 columns there were 370 cu. yds. of concrete.
Forms.—A column form is shown by Fig. 230; it contains approximately 1,000 ft. B. M. of lumber. Ten of these forms were used, so that 10,000 ft. B. M. of form lumber were required for 370 cu. yds. of concrete, or 27 ft. B. M. per cu. yd. of concrete. Each column had a superficial area excluding ends of about 420 sq. ft., so that 420 × 80 = 33,600 sq. ft. was the superficial area of all the columns and 10,000 ft. B. M. ÷ 33,600 sq. ft. = 0.3 ft. B. M., or, say, ⅓ft. B. M., of form lumber was used per square foot of concrete enclosed. The cost of the forms per 1,000 ft. B. M., and, therefore, per form, was:
| Lumber, 1,000 ft. B. M., at $31.75 | $31.75 |
| Labor constructing form | 16.39 |
| ——— | |
| Total per 1,000 ft. B. M. | $48.14 |
