Chapter 6 Measuring Masonry and Finishes Masonry Work

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 15⅝ inches and a joint thickness of ⅜ inches, 112. 5 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 15⅝ inches with ⅜inch 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 – = 0. 134 cu ft/brick – Volume of brick alone = 3⅝ x 15⅝ – = 205. 23 cu in – Thus, 205. 23 / 1728 = 0. 119 cubic feet/brick – Therefore, volume of mortar = 0. 134 – 0. 119 – = 0. 015 cu ft per brick – Mortar volume per sq ft of wall = 0. 015 x 2. 25 – = 0. 035 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.