Page 154 - Masonry and Concrete

Masonry Construction Techniques
153
MASONRY CONSTRUCTION TECHNIQUES

5.4.1 Unit and Mortar Placement T 00LS
One of the most important elements of
A mason’s tools include a steel framing
masonry construction is keeping the wall
square, 48-in. mason’s level, folding rule,
straight, level, and plumb and accurately chalk line, line blocks or line pins, story
maintaining the horizontal and vertical pole, and string for layout; a bricklayer’s
coursing. The initial layout of a wall dis- hammer and brickset for breaking brick;
cussed above included a dry run of units a saw with a masonry blade for cutting
to establish horizontal coursing and adjust block; a hawk or mortar board for holding
head joint spacing as necessary. Vertical small quantities of mortar; a trowel and
coursing can be established by building jointing tools for placing mortar and fin-
ishing joints; and brushes to clean the
leading sections or leads at the ends or cor-
surface of a wall (Figure 5-15). Jointing
ners of walls (Figure 5-16). Vertical cours-
tools include rounded or convex jointers
ing must be carefully measured for the
to produce concave joints, V-jointers,
leads to establish the correct bed joint
raking tools, and others.
thickness and height of each course for the
whole wall. A story pole measured and
marked ahead of time with the height of each course and the thickness
of each mortar bed joint can be used to accurately and consistently
maintain vertical coursing in the leads. A simple story pole can be
made by marking the coursing heights on a straight piece of lumber
that is long enough to mark the coursing for the full height of the wall.
The first course of a lead should be at least four or five units long
and carefully aligned so the wall will be straight and not bowed or
curved. Corners must be laid at true right QUICK>>>TIP
angles of exactly 90 degrees. The second A story pole for modu-
and successive courses of the lead are lar brick can be made by first marking a
racked back one-half unit length in each long 2 4 in 8-in. increments, then lay-
course to establish a typical running bond ing three bricks on edge, spacing 3/8 in.
pattern in which one unit overlaps the between them to allow for the mortar
joints. Three modular brick and three
unit in the course below by half its length.
mortar joints equals 8 in., so these three
A four-foot-long mason’s level or straight
units can be used to mark the individual
2 4 laid carefully along the “rack” of the
courses between each of the 8-in. incre-
lead should touch the corner of each brick
ments (Figure 5-17). For concrete block,
or block (Figure 5-18). Leads are usually each 8-in. increment represents the
built four or five courses higher than the height of one course of 7-5/8-in. modu-
center of the wall, and as each course of lar units with one 3/8-in. bed joint.
the lead is laid, it should be carefully

Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com)
Copyright © 2004 The McGraw-Hill Companies. All rights reserved.
Any use is subject to the Terms of Use as given at the website.