International Building Code Section 2104 – International Building Code 2006 Discussions

International Building Code 2104.1

Masonry construction. Masonry construction shall
comply with the requirements of Sections 2104.1.1 through
2104.5 and with ACI 530.1/ASCE 6/TMS 602.

Tolerances. Masonry, except masonry veneer,
shall be constructed within the tolerances specified in ACI
530.1/ASCE 6/TMS 602.

Placing mortar and units. Placement of mortar
and clay and concrete units shall comply with Sections
2104.1.2.1, 2104.1.2.2, 2104.1.2.3 and 2104.1.2.5. Placement
of mortar and glass unit masonry shall comply with
Sections 2104.1.2.4 and 2104.1.2.5. Placement of thin-bed
mortar and AAC masonry shall comply with Section
2104.1.2.6.

Bed and head joints. Unless otherwise
required or indicated on the construction documents,
head and bed joints shall be 3/8 inch (9.5 mm) thick,
except that the thickness of the bed joint of the starting
course placed over foundations shall not be less than 1/4
inch (6.4 mm) and not more than 3/4 inch (19.1 mm).

Open-end units. Open-end units with
beveled ends shall be fully grouted. Head joints of
open-end units with beveled ends need not be mortared.
The beveled ends shall form a grout key that
permits grouts within 5/8 inch (15.9 mm) of the face of
the unit. The units shall be tightly butted to prevent
leakage of the grout.

Hollow units. Hollow units shall be placed
such that face shells of bed joints are fully mortared.
Webs shall be fully mortared in all courses of piers, columns,
pilasters, in the starting course on foundations
where adjacent cells or cavities are to be grouted, and
where otherwise required. Head joints shall be mortared
a minimum distance from each face equal to the face
shell thickness of the unit.

Solid units. Unless otherwise required or
indicated on the construction documents, solid units
shall be placed in fully mortared bed and head joints. The
ends of the units shall be completely buttered. Head
joints shall not be filled by slushing with mortar. Head
joints shall be constructed by shoving mortar tight
against the adjoining unit. Bed joints shall not be furrowed
deep enough to produce voids.

Glass unit masonry. Glass units shall be
placed so head and bed joints are filled solidly. Mortar
shall not be furrowed.
Unless otherwise required, head and bed joints of
glass unit masonry shall be 1/4 inch (6.4 mm) thick,
except that vertical joint thickness of radial panels shall
not be less than 1/8 inch (3.2 mm). The bed joint thickness
tolerance shall be minus 1/16 inch (1.6 mm) and plus 1/8
inch (3.2 mm). The head joint thickness tolerance shall
be plus or minus 1/8 inch (3.2 mm).

Placement in mortar. Units shall be placed
while the mortar is soft and plastic. Any unit disturbed to
the extent that the initial bond is broken after initial positioning
shall be removed and relaid in fresh mortar.

Thin-bed mortar and AAC masonry units.
AAC masonry construction shall begin with a leveling
course of masonry meeting the requirements of Section
2104.1.2. Subsequent courses of AAC masonry units
shall be laid with thin-bed mortar using a special notched
trowel manufactured for use with thin-bed mortar to
spread the mortar so that it completely fills the bed joints.
Unless otherwise specified, the head joints shall be
similarly filled. Joints inAAC masonry shall be approximately
1/16 inch (1.5 mm) and shall be formed by striking
on the ends and tops ofAACmasonry units with a rubber
mallet. Minor adjustments in unit position shall be made
while the mortar is still soft and plastic by tapping it into
the proper position. Minor sanding of the exposed faces
of AAC masonry shall be permitted to provide a smooth
and plumb surface.

Grouted masonry. Between grout pours, a
horizontal construction joint shall be formed by stopping
all wythes at the same elevation and with the grout stopping
a minimum of 11/2 inches (38 mm) below a mortar
joint, except at the top of the wall. Where bond beams
occur, the grout pour shall be stopped a minimum of 1/2
inch (12.7 mm) below the top of the masonry.

Installation of wall ties. The ends of wall ties
shall be embedded in mortar joints. Wall tie ends shall
engage outer face shells of hollow units by at least 1/2 inch
(12.7 mm). Wire wall ties shall be embedded at least 11/2
inches (38 mm)into the mortar bed of solid masonry units or
solid-grouted hollow units. Wall ties shall not be bent after
being embedded in grout or mortar.

Chases and recesses. Chases and recesses shall be
constructed as masonry units are laid. Masonry directly
above chases or recesses wider than 12 inches (305 mm)
shall be supported on lintels.

Lintels. The design for lintels shall be in accordance
with the masonry design provisions of either Section
2107 or 2108. Minimum length of end support shall be 4
inches (102 mm).

Support on wood. Masonry shall not be supported
on wood girders or other forms ofwood construction
except as permitted in Section 2304.12.

Masonry protection. The top of unfinished
masonry work shall be covered to protect the masonry from
the weather.

Weep holes. Weep holes provided in the outside
wythe of masonry walls shall be at a maximum spacing of
33 inches (838 mm) on center (o.c.).Weep holes shall not be
less than 3/16 inch (4.8 mm) in diameter.

International Building Code 2104.1.1

Tolerances. Masonry, except masonry veneer,
shall be constructed within the tolerances specified in ACI
530.1/ASCE 6/TMS 602.
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International Building Code 2104.1.2

International Building Code 2104.1.2.1

International Building Code 2104.1.2.1.1

International Building Code 2104.1.2.2

International Building Code 2104.1.2.3

International Building Code 2104.1.2.4

International Building Code 2104.1.2.5

International Building Code 2104.1.2.6

International Building Code 2104.1.2.7

International Building Code 2104.1.3

International Building Code 2104.1.4

Chases and recesses. Chases and recesses shall be
constructed as masonry units are laid. Masonry directly
above chases or recesses wider than 12 inches (305 mm)
shall be supported on lintels.

International Building Code 2104.1.5

Lintels. The design for lintels shall be in accordance
with the masonry design provisions of either Section
2107 or 2108. Minimum length of end support shall be 4
inches (102 mm).

International Building Code 2104.1.6

Support on wood. Masonry shall not be supported
on wood girders or other forms ofwood construction
except as permitted in Section 2304.12.

International Building Code 2104.1.7

Masonry protection. The top of unfinished
masonry work shall be covered to protect the masonry from
the weather.

International Building Code 2104.1.8

International Building Code 2104.2

Corbeled masonry. Except for corbels designed per
Section 2107 or 2108, the following shall apply:
1. Corbels shall be constructed of solid masonry units.
2. The maximum corbeled projection beyond the face of
the wall shall not exceed:
2.1. One-half of the wall thickness for multiwythe
walls bonded by mortar or grout and wall ties or
masonry headers or
2.2. One-half the wythe thickness for single wythe
walls, masonry bonded hollow walls,
multiwythe walls with open collar joints and
veneer walls.
3. The maximum projection of one unit shall not exceed:
3.1. One-half the nominal unit height of the unit or
2006 INTERNATIONAL BUILDING CODE 395
MASONRY
3.2. One-third the nominal thickness of the unit or
wythe.
4. The back surface of the corbelled section shall remain
within 1 inch (25 mm) of plane.

Molded cornices. Unless structural support and
anchorage are provided to resist the overturning moment,
the center of gravity of projecting masonry or molded cornices
shall lie within the middle one-third of the supporting
wall. Terra cotta and metal cornices shall be provided with a
structural frame of approved noncombustible material
anchored in an approved manner.

International Building Code 2104.2.1

International Building Code 2104.3

Cold weather construction. The cold weather construction
provisions of ACI 530.1/ASCE 6/TMS 602, Article
1.8 C, or the following procedures shall be implemented when
either the ambient temperature falls below 40F (4C) or the
temperature of masonry units is below 40F (4C).

Preparation.
1. Temperatures of masonry units shall not be less than
20F (-7C) when laid in the masonry. Masonry units
containing frozen moisture, visible ice or snow on
their surface shall not be laid.
2. Visible ice and snow shall be removed from the top
surface of existing foundations and masonry to
receive new construction. These surfaces shall be
heated to above freezing, using methods that do not
result in damage.

Construction. The following requirements shall
apply to work in progress and shall be based on ambient
temperature.

Construction requirements for temperatures
between 40F (4C) and 32F (0C). The following construction
requirements shall be met when the ambient temperature
is between 40F (4C) and 32F (0C):
1. Glass unit masonry shall not be laid.
2. Water and aggregates used in mortar and grout
shall not be heated above 140F (60C).
3. Mortar sand or mixing water shall be heated to produce
mortar temperatures between 40F (4C) and
120F (49C) at the time of mixing. When water
and aggregates for grout are below 32F(0C),
they shall be heated.

Construction requirements for temperatures
between 32F (0C) and 25F (-4C). The
requirements of Section 2104.3.2.1 and the following
construction requirements shall be met when the ambient
temperature is between 32F (0C) and 25F (-4C):
1. The mortar temperature shall be maintained above
freezing until used in masonry.
2. Aggregates and mixing water for grout shall be
heated to produce grout temperature between 70F
(21C) and 120F (49C) at the time of mixing.
Grout temperature shall be maintained above 70F
(21C) at the time of grout placement.
3. Heat AAC masonry units to a minimum temperature
of 40F (4C) before installing thin-bed mortar.

Construction requirements for temperatures
between 25F (-4C) and 20F (-7C). The
requirements of Sections 2104.3.2.1 and 2104.3.2.2 and
the following construction requirements shall be met
when the ambient temperature is between 25F (-4C)
and 20F (-7C):
1. Masonry surfaces under construction shall be
heated to 40F (4C).
2. Wind breaks or enclosures shall be provided when
the wind velocity exceeds 15 miles per hour (mph)
(24 km/h).
3. Prior to grouting, masonry shall be heated to a
minimum of 40F (4C).

Construction requirements for temperatures
below 20F (-7C). The requirements of Sections
2104.3.2.1, 2104.3.2.2 and 2104.3.2.3 and the following
construction requirement shall be met when the ambient
temperature is below 20F (-7C): Enclosures and auxiliary
heat shall be provided to maintain air temperature
within the enclosure to above 32F (0C).

Protection. The requirements of this section and
Sections 2104.3.3.1 through 2104.3.3.5 apply after the
masonry is placed and shall be based on anticipated minimum
daily temperature for grouted masonry and anticipated
mean daily temperature for ungrouted masonry.

Glass unit masonry. The temperature of
glass unit masonry shall be maintained above 40F (4C)
for 48 hours after construction.

AAC masonry. The temperature of AAC
masonry shall be maintained above 32F (0C) for the
first 4 hours after thin-bed mortar application.

Protection requirements for temperatures
between 40F (4C) and 25F (-4C). When the temperature
is between 40F (4C) and 25F (-4C), newly constructed
masonry shall be coveredwith aweather-resistive
membrane for 24 hours after being completed.

Protection requirements for temperatures
between 25F (-4C) and 20F (-7C). When the temperature
is between 25F (-4C) and 20F (-7C), newly
constructed masonry shall be completely covered with
weather-resistive insulating blankets, or equal protection,
for 24 hours after being completed. The time period
shall be extended to 48 hours for grouted masonry, unless
the only cement in the grout isType III portland cement.

Protection requirements for temperatures
below20F (-7C). When the temperature is below20F
(-7C), newly constructed masonry shall be maintained
at a temperature above 32F (0C) for at least 24 hours
after being completed by using heated enclosures, electric
heating blankets, infrared lamps or other acceptable
methods. The time period shall be extended to 48 hours
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for grouted masonry, unless the only cement in the grout
is Type III portland cement.

International Building Code 2104.3.1

International Building Code 2104.3.2

Construction. The following requirements shall
apply to work in progress and shall be based on ambient
temperature.

International Building Code 2104.3.2.1

International Building Code 2104.3.2.2

International Building Code 2104.3.2.3

International Building Code 2104.3.2.4

International Building Code 2104.3.3

Glass unit masonry. The temperature of
glass unit masonry shall be maintained above 40F (4C)
for 48 hours after construction.

AAC masonry. The temperature of AAC
masonry shall be maintained above 32F (0C) for the
first 4 hours after thin-bed mortar application.

International Building Code 2104.3.3.1

Glass unit masonry. The temperature of
glass unit masonry shall be maintained above 40F (4C)
for 48 hours after construction.

International Building Code 2104.3.3.2

AAC masonry. The temperature of AAC
masonry shall be maintained above 32F (0C) for the
first 4 hours after thin-bed mortar application.

International Building Code 2104.3.3.3

International Building Code 2104.3.3.4

International Building Code 2104.3.3.5

International Building Code 2104.4

Hot weather construction. The hot weather construction
provisions of ACI 530.1/ASCE 6/TMS 602, Article 1.8 D,
or the following procedures shall be implemented when the
temperature or the temperature and wind-velocity limits of this
section are exceeded.

Preparation. The following requirements shall be
met prior to conducting masonry work.

Temperature. When the ambient temperature
exceeds 100F (38C), or exceeds 90F (32C) with
a wind velocity greater than 8 mph (3.5 m/s):
1. Necessary conditions and equipment shall be provided
to produce mortar having a temperature
below 120F (49C).
2. Sand piles shall be maintained in a damp, loose
condition.

Special conditions. When the ambient temperature
exceeds 115F (46C), or 105F (40C) with a
wind velocity greater than 8 mph (3.5 m/s), the requirements
of Section 2104.4.1.1 shall be implemented, and
materials and mixing equipment shall be shaded from
direct sunlight.

Construction. The following requirements shall
be met while masonry work is in progress.

Temperature. When the ambient temperature
exceeds 100F (38C), or exceeds 90F (32C) with
a wind velocity greater than 8 mph (3.5 m/s):
1. The temperature of mortar and grout shall be maintained
below 120F (49C).
2. Mixers, mortar transport containers and mortar
boards shall be flushed with cool water before they
come into contact with mortar ingredients or mortar.
3. Mortar consistency shall be maintained by retempering
with cool water.
4. Mortar shall be used within 2 hours of initial mixing.
5. Thin-bed mortar shall be spread no more than 4
feet (1219 mm) ahead of AAC masonry units.
6. AAC masonry units shall be placed within one
minute after spreading thin-bed mortar.

Special conditions. When the ambient temperature
exceeds 115F (46C), or exceeds 105F
(40C) with a wind velocity greater than 8 mph (3.5
m/s), the requirements of Section 2104.4.2.1 shall be
implemented and cool mixing water shall be used for
mortar and grout. The use of ice shall be permitted in the
mixing water prior to use. Ice shall not be permitted in
the mixing water when added to the other mortar or
grout materials.

Protection. When the mean daily temperature
exceeds 100F (38C) or exceeds 90F (32C) with a wind
velocity greater than 8 mph (3.5 m/s), newly constructed
masonry shall be fog sprayed until damp at least three times
a day until the masonry is three days old.

International Building Code 2104.4.1

Preparation. The following requirements shall be
met prior to conducting masonry work.

International Building Code 2104.4.1.1

International Building Code 2104.4.1.2

International Building Code 2104.4.2

Construction. The following requirements shall
be met while masonry work is in progress.

International Building Code 2104.4.2.1

International Building Code 2104.4.2.2

International Building Code 2104.4.3

International Building Code 2104.5

Wetting of brick. Brick (clay or shale) at the time of
laying shall require wetting if the unit’s initial rate of water
absorption exceeds 30 grams per 30 square inches (19 355
mm2) per minute or 0.035 ounce per square inch (1 g/645mm2)
per minute, as determined by ASTM C 67.