Chapter 6 Measuring Masonry and Finishes

Masonry Work Generally It includes clay bricks, concrete bricks and blocks, clay tiles, and natural and artificial stone. This work is usually subcontracted. Here we consider only standard clay brick and concrete block masonry. Other work is measured in a similar fashion to that described here.

Measuring Masonry Work Masonry work is measured net in place; allowances for waste etc. are considered later. The units of measurement for masonry are generally the number of masonry pieces such as concrete blocks calculated in a two-stage process: –Measure area of masonry –Number of masonry units = area measured x a factor No deductions shall be made for openings less than 10 square feet.

Masonry Conversion Factors Reference works publish tables that list quantities of bricks or blocks per square foot area of masonry. –For example, a 4½-inch wall with ⅜-inch brick joints and laid in running bond will have 6.67 bricks per square foot of wall. –For example, for a wall of 8-inch nominal thickness built with standard blocks of size 7⅝ by 7⅝ by 15⅝ inches and a joint thickness of ⅜ inches, blocks together with 6-cubic feet of mortar are required for 100-square feet of wall.

Calculating Conversion Factors The estimator may have to calculate the conversion factors: –If bricks are of size 3⅝ by 3⅝ by 15⅝ inches with ⅜- inch wide mortar joints, what is the conversion factor? The length of a brick is 15⅝ plus a mortar joint ⅜ = 16”. The height of a brick is 3⅝ plus a mortar joint ⅜ = 4”. So, the area of the face of a brick, including mortar joints, is 16 x 4 = 64 square inches. 1 sq ft (144 square inches) / 64 square inches = 2.25 Therefore, there are 2¼ bricks for each sqare foot of wall face.

Calculating a Factor for Mortar Volume of mortar per square foot of wall: –Volume of brick + joints = 3⅝ x (3⅝+⅜) x (15⅝+⅜) – = 232 cu in/brick –And: since 1 cu. foot = 1728 cu in –Volume of brick + joints = 232 / 1728 – = cu ft/brick –Volume of brick alone = 3⅝ x 3⅝ x 15⅝ –= cu in –Thus, / 1728= cubic feet/brick –Therefore, volume of mortar = – –= cu ft per brick –Mortar volume per sq ft of wall = x 2.25 –= cu ft per sq ft.

Measuring Work (1 of 3) Masonry work (including scaffolding and hoisting) is measured separately in the following categories: –Facings –Backing to facings –Walls and partitions –Furring to walls –Fire protection

Measuring Work (2 of 3) Expansion joints or control joints in masonry are measured in lineal feet and fully described. Mortar is measured in cubic feet. Wire reinforcement is measured in lineal feet. Building in anchor bolts, sleeves, brackets, and similar items are enumerated. Building in lintels, sills, copings, flashings, and similar items are measured in lineal feet. Rigid insulation to masonry work is measured in square feet.

Measuring Work (3 of 3) Bricks are enumerated describing the type and dimensions of bricks. Brick ties are enumerated and fully described. Concrete block masonry units are enumerated stating the type, and size of blocks. Loose fill or foam insulation to blockwork cores is measured in cubic yards. Concrete to core fills and bond beams (lintels) are measured in cubic yards. Reinforcing steel to core fills and bond beams is measured in lineal feet.

Takeoff Exercise Takeoff the masonry work for the house example shown on Figure 3.5 drawings and masonry details on Figure 6.2. See Figure 6.3.