8 BRICK MASONRY
Stone and brick
masonry: The
strongest and
most durable of
pre-industrial
building materials
Mycenae, Lions Gate
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
8 BRICK MASONRY
MORTAR
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
MORTAR
Mortar
• Cushions masonry
units, ensuring
uniform bearing one
against the other
• Seals joints between
the masonry units,
minimizing the flow of
air and water
• Adheres units,
providing resistance
to lateral forces from
wind, earthquakes
Fundamentals of Building Construction, Materials & Methods, 5th Edition
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MORTAR
Mortar
• In combination with brick, contributes to the appearance of
the wall
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
MORTAR
Portland Cement-Lime Mortar
Ingredients: Portland cement
• Primarily calcium silicates
• Sources of calcium: Limestone,
marble, and other minerals
• Sources of silica: Clay, sand,
shale, marl
• Portland cement is an hydraulic
cement: It hardens by
chemically combining with
water (hydration).
• Lesser quantities of compounds
of iron, aluminum, magnesium,
and sulfate improve the
hydration process.
• Very fine particle size: 0.0004
to 0.0006 inches diameter
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MORTAR
Portland Cement-Lime Mortar
Ingredients: Aggregate
• Natural sand
• Manufactured sand made
from crushed stone, gravel,
or furnace slag
• Particle size: A well-graded
mix with particles ranging in
size from 0.003 – 0.187
inches in diameter
• Sands must be free of
contaminants, physically
sound, and not chemically
reactive with the other mortar
ingredients.
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Copyright © 2009 J. Iano. All rights reserved.
MORTAR
Portland Cement-Lime Mortar
Ingredients: Hydrated lime
• Quicklime: Limestone and
other minerals are finely
ground and heated to
produce calcium and
magnesium oxides: CaO/MgO.
• Hydrated lime: Sufficient
water is added to quicklime
to slake or chemically
convert the oxides to
hydroxides: Ca(OH)2/Mg(OH)2.
• Hydrated lime remains a dry
powder.
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MORTAR
Portland Cement-Lime Mortar
Ingredients: Water
• Clean, neutral pH, free of
contaminants or organic
material
• Potable water is generally
considered suitable.
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MORTAR
The Mortar Mix
• There is almost one cubic foot
of sand in a cubic foot or
mortar. Sand provides the basic
structural capacity of the
hardened mortar.
• Cement is the glue that binds
the sand particles together.
• Lime improves the workability
of mortar in its plastic state.
• A minimum amount of water is
necessary for the chemical
hydration of the cement;
additional water is added to
produce a working consistency
to the wet mortar.
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Copyright © 2009 J. Iano. All rights reserved.
MORTAR
Blended hydraulic
cement
• Portland cement
mixed with other
cementitious
materials
• Replaces
portland cement
in cement-lime
mortar mix
Cement
Portland cement-lime
mortar
Mortar with blended
hydraulic cement
Mortar with masonry
cement
Mortar with mortar
cement
Lime mortar
(non- hydraulic)
Fundamentals of Building Construction, Materials & Methods, 5th Edition
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Lime & other
workability
agents
lime
portland
cement
blended
lime
hydraulic
cement
masonry cement
mortar cement
(none)
lime
Aggregate
sand
sand
sand
sand
sand
MORTAR
Masonry cement
• Proprietary mortar mix
of cementitious
materials, lime,
plasticizers, and other
ingredients
• No added lime
• Convenience and
consistent quality of
pre-mixed ingredients
• Good workability, and
improvements in some
properties of hardened
mortar such as
reduced drying
shrinkage
• Lower bond strength
than cement-lime
mortars
Cement
Portland cement-lime
mortar
Mortar with blended
hydraulic cement
Mortar with masonry
cement
Mortar with mortar
cement
Lime mortar
(non- hydraulic)
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
Lime & other
workability
agents
lime
portland
cement
blended
lime
hydraulic
cement
masonry cement
mortar cement
(none)
lime
Aggregate
sand
sand
sand
sand
sand
MORTAR
Mortar cement
• A proprietary premixed product, like
masonry cement
• But produced to a
standard that
assures higher bond
strength comparable
to cement-lime
mortar
Cement
Portland cement-lime
mortar
Mortar with blended
hydraulic cement
Mortar with masonry
cement
Mortar with mortar
cement
Lime mortar
(non- hydraulic)
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
Lime & other
workability
agents
lime
portland
cement
blended
lime
hydraulic
cement
masonry cement
mortar cement
(none)
lime
Aggregate
sand
sand
sand
sand
sand
MORTAR
Lime Mortar
• No hydraulic cement
• Cures by a chemical
reaction called
carbonation, where
atmospheric CO2,
combines with the
hydroxides in the lime
to create carbonates
• Has some ability to
self-heal hairline
cracks that may
develop over time; as
water and air enter the
joint, carbonation can
occur and repair the
joint
• Used primarily for the
restoration of historic
masonry structures
Cement
Portland cement-lime
mortar
Mortar with blended
hydraulic cement
Mortar with masonry
cement
Mortar with mortar
cement
Lime mortar
(non- hydraulic)
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
Lime & other
workability
agents
lime
portland
cement
blended
lime
hydraulic
cement
masonry cement
mortar cement
(none)
lime
Aggregate
sand
sand
sand
sand
sand
MORTAR
Mortar Admixtures
• Pigments, colored
aggregate
• Bond enhancers: Improve
flexural strength, freezethaw resistance
• Set accelerators and
retarders: Adjust setting
time in cold or hot weather
• Water repellents: Improve
water resistance (for
concrete masonry units
only)
• Workability enhancers:
Ease placement of wet
mortar
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
MORTAR
Mortar Types
• Higher-strength mortars have
a higher proportion of cement
to lime in the mortar mix,
resulting in higher
compressive strength in the
hardened mortar.
• Higher strength mortars are
more expensive and have
poorer workability
characteristics in comparison
to lower-strength mortars.
• In general, the lowest
strength mortar suitable for a
particular job is the optimal
choice.
• Type S and Type N mortars
are the most commonly
specified.
ASTM C270
Designation
Type M
Type S
Type N
Type O
Type K
Uses
Highest strength
Very high-strength masonry
Masonry subject to severe freeze-thaw
Masonry in contact with the earth
Reinforced loadbearing masonry
Exterior veneer subjected to high wind forces
or seismic forces
Nonloadbearing masonry
Exterior masonry not subject to severe
lateral loads
Interior nonloadbearing masonry
Historic masonry restoration
Lowest strength
Historic masonry restoration
(not part of ASTM C270 standard)
Designations for mortar types, in decreasing order of
strength, come from every other letter in the phrase
“MaSoN wOrK”.
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
MORTAR
Mortar Type Specification: Proportion Specification
• Mortar types are defined by the proportion of
ingredients.
• Proportion specification is the simpler and more
common method of defining mortar requirements.
• Note the higher lime content of lower-strength mortar
types.
• Note that no lime is added to mortar cement or
masonry cement mixes.
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
MORTAR
Mortar Type Specification: Property Specification
• Mortar types are defined by minimum strength and
other properties demonstrated through laboratory
testing for the proposed mix.
• This specification method is most suitable to large
projects, where the added cost and complexity of
laboratory testing can be offset by more flexibility in
selecting ingredients and proportions in the mortar
mix.
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
8 BRICK MASONRY
BRICK MASONRY
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
BRICK MASONRY
Brick Raw Materials
Preparation
• Natural clays are
excavated from the
earth.
• These raw materials
are ground up and
screened to control
particle size.
• Water is added to
achieve a plastic
consistency ready for
molding into bricks.
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
BRICK MASONRY
Brick Forming: Extruded or Stiff
mud process bricks
• Moderately moist clay is
extruded through dies and
then sliced into individual
units.
• Generally least expensive
molding method
• Accounts for approximately
90% of US made bricks
• The extrusion process
naturally produces brick units
with a smooth face and high
dimensional uniformity.
• Various post-extrusion
distressing steps can be used
to create bricks with greater
variation in shape and surface
texture (right).
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
BRICK MASONRY
Brick Forming: Molded bricks
• Soft mud process: Relatively
moist clay is pressed into
individual molds
– Water-struck: Molds are pre-wetted
– Sand-struck: Molds are pre-dusted
with sand
– May be hand- or machine-pressed
•
•
•
Dry-press process: Low-plasticity
clays are kept relatively dry and
stiff, and machine-pressed into
steel molds at high pressure.
Molded bricks frequently are
associated with more natural
variation in texture and
dimensional uniformity than
extruded bricks.
Molded brick costs vary with the
molding process, but are
frequently more expensive than
extruded brick.
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
BRICK MASONRY
Brick Firing
• After forming, bricks are
dried and then packed
into a firing kiln, where
they pass through various
stages of drying and
chemical transformation.
• Tunnel kiln (right): Brick
loads pass continuously
from one end of the kiln to
the other.
• Periodic kiln: Batches of
bricks are loaded, fired,
cooled, and removed.
• Firing takes 10 to 40
hours.
• Brick placement and firing
conditions affect finished
brick color, uniformity of
shape, hardness, and
other physical properties.
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
BRICK MASONRY
Brick Sizes
• Bricks are available in many sizes and standard sizes vary
regionally.
• Some bricks are sized so that the dimension of one brick plus one
mortar joint equals a convenient nominal dimension.
• Example: A modular brick combined with a mortar joint occupies
4 inches in width (3 5/8" + 3/8") and 8 inches in length (7 5/8" +
3/8"). Three courses occupy 8 inches in height( 3 x [2 1/4" + 3/8"] ).
Example Modular–Sized Brick Sizes
Nominal Dimensions, in.
Joint Thickness, in.
W
H
L
Vertical
Coursing
3/8
1/2
3 5/8
3 1/2
2 1/4
7 5/8
7 1/2
3 courses =
8 in.
8
3/8
1/2
3 5/8
3 1/2
2 3/4
2 13/16
7 5/8
7 1/2
5 courses =
8 in.
4
8
3/8
1/2
3 5/8
3 1/2
3 5/8
3 1/2
7 5/8
7 1/2
1 course =
4 in.
4
2
12
3/8
1/2
3 5/8
3 1/2
1 5/8
1 1/2
11 5/8
11 1/2
2 course =
4 in.
4
4
16
3/8
1/2
3 5/8
3 1/2
3 5/8
3 1/2
15 5/8
15 1/2
1 course =
4 in.
W
H
L
Modular
4
2 2/3
8
Engineer
Modular
4
3 1/5
Closure
Modular
4
Roman
Meridian
Actual Dimensions, in.
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
BRICK MASONRY
Brick Sizes
• Other bricks do not necessarily conform to convenient
dimensions. Note the non-modular-sized lengths of the
example bricks in the table below.
Standard
Example Non-Modular-Sized Brick Sizes
Nominal Dimensions, in.
Joint Thickness, in.
Actual Dimensions, in.
W
H
L
W
H
3/8
3 5/8
2 1/4
1/2
3 1/2
L
8
Vertical
Coursing
3 courses = 8
in.
Engineer
Standard
3/8
1/2
3 5/8
3 1/2
2 3/4
2 13/16
8
5 course = 8
in.
Closure
Standard
3/8
1/2
3 5/8
3 1/2
3 5/8
3 1/2
8
1 course = 4
in.
King
3/8
2 3/4 - 3
2 5/8
- 2 3/4
9 5/8
- 9 3/4
5 courses =
16 in.
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
BRICK MASONRY
Special Shapes and Sizes
• Special or custom-shaped bricks
can be used to form arches,
water tables, and many other
surfaces and features.
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
BRICK MASONRY
Brick Classifications
• Solid brick: Not less
than 75% solid (in any
section cut
perpendicular to
bearing).
• Solid bricks are
frequently not 100%
solid, to reduce weight
and the costs of firing.
Cored, solid bricks are lighter in
weight than fully solid units.
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Frogged, solid bricks are
less prone to shifting on a
wet mortar bed.
BRICK MASONRY
Brick Classifications
• Hollow brick: Up to
60% void
• With hollow brick,
larger sized units can
be kept lighter in
weight
• Because of their lighter
weight, hollow bricks
require less energy to
fire.
• The larger voids in
hollow brick readily
accommodate steel
reinforcing in
reinforced brick
masonry.
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
BRICK MASONRY
Brick Classifications
• Facing brick: Brick
with appearance
characteristics
graded for exposed
applications
• Building brick (right):
Brick intended for
concealed locations
where appearance
is not a concern
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BRICK MASONRY
Brick Grade: Defines
durability (e.g.,
compressive strength,
absorption, freeze-thaw
resistance)
• Grade NW: Interior
brick, concealed building
brick, and other brick not
exposed to the weather
• Grade MW: Above
grade brick only, in
regions of negligible
weathering (see map)
• Grade SW: Any
weathering region,
above or below grade
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
BRICK MASONRY
Brick Type: Defines uniformity in size and shape
• Applies only to facing brick
• Less uniform bricks, which may be considered more
aesthetically desirable, may be more expensive than
more uniform bricks.
• More uniform bricks are more suitable to applications
where close dimensional tolerances must be
maintained, such as in a brick masonry curtain wall.
Fundamentals of Building Construction, Materials & Methods, 5th Edition
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BRICK MASONRY
Brickwork Terminology
• Course: One horizontal
row of bricks
• Bed Joint: Horizontal joint
between courses
• Head Joint: Vertical joint
between bricks in same
course
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Copyright © 2009 J. Iano. All rights reserved.
BRICK MASONRY
Brickwork Terminology:
• Wythe: One vertical stack
of bricks
• Collar Joint: Vertical joint
between wythes
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BRICK MASONRY
Brickwork Terminology:
• Rowlock: Brick laid on its
face, with end visible
• Stretcher: Brick laid flat,
with face visible
• Header: Brick laid flat, with
end visible
• Soldier: Brick laid on its
end, with its face visible
• Sailor: Like a soldier, but
with its broader side visible
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BRICK MASONRY
Brick Bonds
• Headers or rowlocks
in a multi-wythe wall
serve an important
functional purpose,
tying together the two
wythes.
• In a single-wythe
wall, different brick
bonds may be
chosen purely for the
visual patterns they
create in the exposed
face of the wall.
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
BRICK MASONRY
Brick Bonds:
• Running Bond: All
stretchers
• Common Bond:
Stretcher courses,
with a header row
usually every 5 or 6
courses
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BRICK MASONRY
Brick Bonds
• English Bond:
Alternating stretcher
and header courses
• Flemish Bond:
Alternating stretchers
and headers in each
course
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
BRICK MASONRY
Brick Masonry Dimensions
• To the greatest extent possible, brick masonry wall dimensions should be conform to
the brick module, minimizing the need to cut bricks or work with very small pieces.
• Depending on the type measurement, the number of joint widths in the dimension
may be one more, the same, or one less, than the number of bricks.
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
BRICK MASONRY
Laying Bricks
• Corner leads are
constructed ahead of
the rest of the wall.
• Levels and string
lines are used to
keep the wall straight
and true.
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
BRICK MASONRY
Joint Tooling
• Compacts joint
surface to make it
more durable and
water-resistant
• Neatens joint
appearance
• The concave joint
and vee joint shed
water most
effectively and are
the most resistant to
freeze-thaw.
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.
BRICK MASONRY
Spanning Openings
• Lintels (steel angle, stone, precast
concrete, reinforced)
• Arches
• Corbelling
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BRICK MASONRY
Reinforced Brick
Masonry (RBM)
• Steel reinforcing and
grouting are added to
the masonry wall, to
increase its strength,
especially in bending
and shear.
• Bottom image: a twowythe RBM panel is
load tested.
Fundamentals of Building Construction, Materials & Methods, 5th Edition
Copyright © 2009 J. Iano. All rights reserved.