Estimating in Building Construction

Masonry 129

Wall ties are often used for securing random, rubble,
and ashlar masonry to the backup material. The type of wall
tie specified must be noted, as must the number of wall ties
per square foot. Divide this into the total square footage to
determine the total number of ties required.
Cleaning must be allowed for as outlined in Section
11–19. Flashing should be taken off by the square foot and
lintels by the linear foot. In each case note the type required,
the supplier, and the installer.
Stone trim is used for door and windowsills, steps, cop-
ings, and moldings. The supplier prices trim by the linear
foot or as a lump sum. Some type of anchor or dowel
arrangement is often required for setting the pieces. The
supplier will know who is supplying the anchors and dowels,
and who will provide the anchor and dowel holes. The holes
must be larger than the dowels being used.
Large pieces of cut stone may require cranes or other
lifting devices to move it and set it in place. When large
pieces of stone are being used as facing on a building, special
inserts and attachments to hold the stone securely in place
will be required.
All the aforementioned factors or items will also affect
the labor hours required to put the stone in place.

11–16 Mortar

Themortarused for masonry units may consist of portland
cement, mortar, sand, and hydrated lime; or of masonry
cement and sand. The amounts of each material required
vary depending on the proportions of the mix selected, the
thickness of the mortar joint (3/8 inch is a common joint
thickness, but 1/4- and 1/2-inch joints are also used), and the
color of the mortar. Dry mortar mix (a premixed combina-
tion of cement, lime, and sand) may be used on a project.
There has been an increase in the use of colored mortar on
the work; colors commonly used are red, brown, white, and
black, but almost any color may be specified. Pure white
mortar may require the use of white cement and white mor-
tar sand; the use of regular mortar sand will generally result
in a creamy color. The other colors are obtained by adding
color pigments to the standard mix. Considerable trial and
error may be required before a color acceptable to the owner
and architect/engineer is found.
When both colored and gray mortars are required on
the same project, the mixer used to mix the mortar must be
thoroughly cleaned between mixings. If both types will be
required, it may be most economical to use two mixers: one
for colored mortar and the other for gray. White mortar
should never be mixed in the mixer that is used for colored
or gray mortar unless the mixer has been thoroughly
cleaned.

EXAMPLE 11-3 MORTAR TAKEOFF

Example 11-1 contains 803 sf of block. Figure 11.6 details mortar
at 3.2 cf per 100 sf of face area. Therefore, the required mortar

would be

From Example 11-2, there were 865 sf of brick. Using Figure 11.6,

the required mortar is 7.2 cf per 100 sf of the face wall area. There-

fore, the required mortar for the brick would be



Labor. The amount of labor required for mortar is usu-

ally considered a part of the labor to lay the masonry units.

11–17 Accessories

Masonry wall reinforcing.Steel reinforcing, which comes in a

wide variety of styles and wire gauges, is placed continuously

in the mortar joints (Figures 11.15 and 11.16). It is used pri-

marily to minimize shrinkage, temperature, and settlement

cracks in masonry, as well as to provide shear transfer to the

steel. The reinforcing is generally available in lengths up to

20 feet. The estimator must determine the linear footage

required. The drawings and specifications must be checked

to determine the spacing required (sometimes every course,

often every second or third course). The reinforcement is

also used to tie the outer and inner wythes together in cavity

wall construction. The reinforcing is available in plain or

corrosion-resistant wire. The estimator should check the

specifications to determine what is required and check with

local suppliers to determine prices and availability of the

specified material.

In calculating this item for 8high block, the easiest

method for larger quantities (over 1,500 sf ) is to multiply the

square footage by the factor given:

Reinforcement every course 1.50

Second course 0.75

Third course 0.50

To this amount, add 5 percent waste and 5 percent lap.

For small quantities, the courses involved and the length of

each course must be figured. Deduct only openings in excess

of 50 sf.

Control Joints. A control joint is a straight vertical joint

that cuts the masonry wall from top to bottom. The horizon-

tal distance varies from 1/2 to about 2 inches. The joint must

also be filled with some type of material; materials usually

specified are caulking, neoprene and molded rubber, and cop-

per and aluminum. These materials are sold by the linear foot

and in a variety of shapes. Check the specifications to find the

types required and check both the drawings and the specifica-

tions for the locations of control joints. Extra labor is involved

in laying the masonry, since alternate courses utilizing half-

size units will be required to make a straight vertical joint.

Waste@ 40 percent 87 cf

7.2 cf per square62 cf

Mortar for brick8.65 squares of face area

Waste@ 40 percent 36 cf

3.2 cf per square26 cf

Mortar for block8.03 squares of face area