Masonry Magazine September 1969 Page. 22
Estimating Wall Cost
provides complete flexibility of wall layout and complete coordination with other masonry products as well as windows, doors and other items.
Standard dimensions for modular concrete masonry units are equal to the nominal dimension less the thickness of one mortar joint of %-inch. Thus, the common nominal 8-inch high by 16-inch long concrete masonry unit has a standard height of 7% inches and a standard length of 15% inches. When laid into the wall with a %-inch modular joint of mortar, the unit always occupies an area of 8 x 16 inches; 112.5 units per 100 square feet of wall area, not including allowance for waste and breakage. Greatest economy is achieved when walls are laid out to the 4-inch modular grid, see Figure 1, so as to eliminate the need for cutting and fitting of units at the job site. Operations which waste materials slow up construction and add greatly to its cost and labor.
Estimating wall cost for concrete masonry consists of: (1) Determining the amount of materials that will be required for the job. (2) Determining the equipment that will be either required for the job or that could be employed to an economic advantage, (3) Determining the amount of labor that will be required, and (4) Summing up the three items. The following procedure is but one of several that have proven successful. Obtain the length and height of all masonry walls and the total number of square feet. Do not count corners twice, but have your estimate show as accurately as possible the total wall area. Allow deductions in full for all openings regardless of their size. When allowing deductions for windows and doors, note the number of sash or jamb block and the type of lintel specified. If lintels are masonry, record the required number of units. Note and record the lineal feet of joint reinforcement or other steel reinforcement in the case of reinforced concrete masonry construction. Also indicate the total lineal footage of control joints, if employed, and the number of control joint units of control joint units. Then calculate the total number of concrete units required for the total wall area; that is, gross wall area minus any openings. This number of masonry units will include jamb, sash, lintel, bond beam and control joint units. These latter units are then deducted from the total to give the number of stretcher units required, see Table 2.
Having determined the total number of the various types of masonry
TABLE 1. COST OF 100 SQUARE FEET OF CONCRETE MASONRY WALL
MATERIALS:
Masonry Units:
Reinforcement, lb:
Mortar, cf.:
Grout, cf.:
Insulation, cf.:
Other:
LABOR:
Mason, mh.:
Laborer, mh.:
Hoisting Eng., mh.:
Other:
EQUIPMENT:
1.
2.
3.