International Building Code Section 2103


International Building Code 2103.1

Concrete masonry units. Concrete masonry units
shall conform to the following standards: ASTM C 55 for concrete
brick; ASTM C 73 for calcium silicate face brick; ASTM
C 90 for load-bearing concrete masonry units or ASTM C 744
for prefaced concrete and calcium silicate masonry units.

International Building Code 2103.10

Mortars for ceramic wall and floor tile. Portland
cement mortars for installing ceramic wall and floor tile shall
comply with ANSI A108.1A and ANSI A108.1B and be of the
compositions indicated in Table 2103.10.
TABLE 2103.10
CERAMIC TILE MORTAR COMPOSITIONS
LOCATION MORTAR COMPOSITION
Walls
Scratchcoat 1 cement; 1/5 hydrated lime;
4 dry or 5 damp sand
Setting bed and
leveling coat
1 cement; 1/2 hydrated lime;
5 damp sand to 1 cement
1 hydrated lime, 7 damp sand
Floors Setting bed
1 cement; 1/10 hydrated lime;
5 dry or 6 damp sand; or 1
cement; 5 dry or 6 damp sand
Ceilings Scratchcoat and
sand bed
1 cement; 1/2 hydrated lime;
21/2 dry sand or 3 damp sand

Dry-set portland cement mortars. Premixed
prepared portland cement mortars, which require only the
addition of water and are used in the installation of ceramic
tile, shall comply with ANSI A118.1. The shear bond
strength for tile set in such mortar shall be as required in
accordance with ANSI A118.1. Tile set in dry-set portland
cement mortar shall be installed in accordance with ANSI
A108.5.

Latex-modified portland cement mortar.
Latex-modified portland cement thin-set mortars in which
latex is added to dry-set mortar as a replacement for all or
part of the gauging water that are used for the installation of
ceramic tile shall comply with ANSI A118.4. Tile set in
latex-modified portland cement shall be installed in accordance
with ANSI A108.5.
2006 INTERNATIONAL BUILDING CODE
MASONRY
Epoxy mortar. Ceramic tile set and grouted with

chemical-resistant epoxy shall comply with ANSI A118.3.
Tile set and grouted with epoxy shall be installed in accordance
with ANSI A108.6.

Furan mortar and grout. Chemical-resistant
furan mortar and grout that are used to install ceramic tile
shall comply with ANSI A118.5. Tile set and grouted with
furan shall be installed in accordance with ANSI A108.8.

Modified epoxy-emulsion mortar and grout.
Modified epoxy-emulsion mortar and grout that are used to
install ceramic tile shall comply with ANSI A118.8. Tile set
and grouted with modified epoxy-emulsion mortar and
grout shall be installed in accordance with ANSI A108.9.

Organic adhesives. Water-resistant organic
adhesives used for the installation of ceramic tile shall comply
with ANSI A136.1. The shear bond strength after water
immersion shall not be less than 40 psi (275 kPa) for Type I
adhesive and not less than 20 psi (138 kPa) for Type II adhesive
when tested in accordance with ANSI A136.1. Tile set
in organic adhesives shall be installed in accordance with
ANSI A108.4.

Portland cement grouts. Portland cement
grouts used for the installation of ceramic tile shall comply
with ANSI A118.6. Portland cement grouts for tile work
shall be installed in accordance with ANSI A108.10.

International Building Code 2103.10.1

Dry-set portland cement mortars. Premixed
prepared portland cement mortars, which require only the
addition of water and are used in the installation of ceramic
tile, shall comply with ANSI A118.1. The shear bond
strength for tile set in such mortar shall be as required in
accordance with ANSI A118.1. Tile set in dry-set portland
cement mortar shall be installed in accordance with ANSI
A108.5.

International Building Code 2103.10.2

Latex-modified portland cement mortar.
Latex-modified portland cement thin-set mortars in which
latex is added to dry-set mortar as a replacement for all or
part of the gauging water that are used for the installation of
ceramic tile shall comply with ANSI A118.4. Tile set in
latex-modified portland cement shall be installed in accordance
with ANSI A108.5.
2006 INTERNATIONAL BUILDING CODE 391
MASONRY

International Building Code 2103.10.3

Epoxy mortar. Ceramic tile set and grouted with
chemical-resistant epoxy shall comply with ANSI A118.3.
Tile set and grouted with epoxy shall be installed in accordance
with ANSI A108.6.

International Building Code 2103.10.4

Furan mortar and grout. Chemical-resistant
furan mortar and grout that are used to install ceramic tile
shall comply with ANSI A118.5. Tile set and grouted with
furan shall be installed in accordance with ANSI A108.8.

International Building Code 2103.10.5

Modified epoxy-emulsion mortar and grout.
Modified epoxy-emulsion mortar and grout that are used to
install ceramic tile shall comply with ANSI A118.8. Tile set
and grouted with modified epoxy-emulsion mortar and
grout shall be installed in accordance with ANSI A108.9.

International Building Code 2103.10.6

Organic adhesives. Water-resistant organic
adhesives used for the installation of ceramic tile shall comply
with ANSI A136.1. The shear bond strength after water
immersion shall not be less than 40 psi (275 kPa) for Type I
adhesive and not less than 20 psi (138 kPa) for Type II adhesive
when tested in accordance with ANSI A136.1. Tile set
in organic adhesives shall be installed in accordance with
ANSI A108.4.

International Building Code 2103.10.7

Portland cement grouts. Portland cement
grouts used for the installation of ceramic tile shall comply
with ANSI A118.6. Portland cement grouts for tile work
shall be installed in accordance with ANSI A108.10.

International Building Code 2103.11

Mortar forAACmasonry. Thin-bed mortar forAAC
masonry shall comply with Section 2103.11.1. Mortar for leveling
courses of AAC masonry shall comply with Section
2103.11.2.

Thin-bed mortar for AAC masonry. Thin-bed
mortar forAACmasonry shall be specifically manufactured
for use with AAC masonry. Testing to verify mortar properties
shall be conducted by the thin-bed mortar manufacturer
and confirmed by an independent testing agency:
1. The compressive strength of thin-bed mortar, as
determined by ASTM C 109, shall meet or exceed the
strength of the AAC masonry units.
2. The shear strength of thin-bed mortar shall meet or
exceed the shear strength of the AAC masonry units
for wall assemblages tested in accordance with
ASTM E 519.
3. The flexural tensile strength of thin-bed mortar shall
not be less than the modulus of rupture of the masonry
units. Flexural strength shall be determined by testing
in accordance with ASTM E 72 (transverse load test),
ASTM E 518 Method A (flexural bond strength test)
or ASTM C 1072 (flexural bond strength test).
3.1. For conducting flexural strength tests in accordance
with ASTM E 518, at least five test
specimens shall be constructed as
stack-bonded prisms at least 32 inches (810
mm) high. The type of mortar specified by the
AAC unit manufacturer shall be used.
3.2. For flexural strength tests in accordance with
ASTM C 1072, test specimens shall be constructed
as stack-bonded prisms comprised
with at least three bed joints. A total of at least
five joints shall be tested using the type of
mortar specified by the AAC unit manufacturer.
4. The splitting tensile strength ofAACmasonry assemblages
composed of two AAC masonry units bonded
with one thin-bed mortar joint shall be determined in
accordance with ASTM C 1006 and shall equal or
exceed 2.4 f ‘?AAC .

Mortar for leveling courses of AAC masonry.
Mortar used for the leveling courses of AAC masonry shall
conform to Section 2103.8 and shall be Type M or S.

International Building Code 2103.11.1

Thin-bed mortar for AAC masonry. Thin-bed
mortar forAACmasonry shall be specifically manufactured
for use with AAC masonry. Testing to verify mortar properties
shall be conducted by the thin-bed mortar manufacturer
and confirmed by an independent testing agency:
1. The compressive strength of thin-bed mortar, as
determined by ASTM C 109, shall meet or exceed the
strength of the AAC masonry units.
2. The shear strength of thin-bed mortar shall meet or
exceed the shear strength of the AAC masonry units
for wall assemblages tested in accordance with
ASTM E 519.
3. The flexural tensile strength of thin-bed mortar shall
not be less than the modulus of rupture of the masonry
units. Flexural strength shall be determined by testing
in accordance with ASTM E 72 (transverse load test),
ASTM E 518 Method A (flexural bond strength test)
or ASTM C 1072 (flexural bond strength test).
3.1. For conducting flexural strength tests in accordance
with ASTM E 518, at least five test
specimens shall be constructed as
stack-bonded prisms at least 32 inches (810
mm) high. The type of mortar specified by the
AAC unit manufacturer shall be used.
3.2. For flexural strength tests in accordance with
ASTM C 1072, test specimens shall be constructed
as stack-bonded prisms comprised
with at least three bed joints. A total of at least
five joints shall be tested using the type of
mortar specified by the AAC unit manufacturer.
4. The splitting tensile strength ofAACmasonry assemblages
composed of two AAC masonry units bonded
with one thin-bed mortar joint shall be determined in
accordance with ASTM C 1006 and shall equal or
exceed 2.4 f ‘?AAC .

International Building Code 2103.11.2

Mortar for leveling courses of AAC masonry.
Mortar used for the leveling courses of AAC masonry shall
conform to Section 2103.8 and shall be Type M or S.

International Building Code 2103.12

Grout. Grout shall conform to Table 2103.12 or to
ASTMC476. When grout conforms toASTMC476, the grout
shall be specified by proportion requirements or property
requirements.

International Building Code 2103.13

Metal reinforcement and accessories. Metal reinforcement
and accessories shall conform to Sections 2103.13.1
through 2103.13.8.

Deformed reinforcing bars. Deformed reinforcing
bars shall conform to one of the following standards:
ASTMA615 for deformed and plain billet-steel bars
for concrete reinforcement; ASTM A 706 for low-alloy
steel deformed bars for concrete reinforcement; ASTM A
767 for zinc-coated reinforcing steel bars; ASTM A 775 for
epoxy-coated reinforcing steel bars; and ASTM A 996 for
rail and axle steel-deformed bars for concrete reinforcement.

Joint reinforcement. Joint reinforcement shall
comply with ASTM A 951. The maximum spacing of
crosswires in ladder-type joint reinforcement and point of
connection of cross wires to longitudinal wires of truss-type
reinforcement shall be 16 inches (400 mm).

Deformed reinforcing wire. Deformed reinforcing
wire shall conform to ASTM A 496.

Wire fabric.Wire fabric shall conform toASTM
A 185 for plain steel-welded wire fabric for concrete reinforcement
or ASTM A 497 for welded deformed steel wire
fabric for concrete reinforcement.
2006 INTERNATIONAL BUILDING CODE 393
MASONRY

Anchors, ties and accessories. Anchors, ties
and accessories shall conform to the following standards:
ASTM A 36 for structural steel; ASTM A 82 for plain steel
wire for concrete reinforcement; ASTM A 185 for plain
steel-welded wire fabric for concrete reinforcement;ASTM
A 240 for chromium and chromium-nickle stainless steel
plate, sheet and strip; ASTM A 307 Grade A for anchor
bolts; ASTM A 480 for flat rolled stainless and heat-resisting
steel plate, sheet and strip; and ASTM A 1008 for
cold-rolled carbon steel sheet.

Prestressing tendons. Prestressing tendons
shall conform to one of the following standards:
1. Wire . . . . . . . . . . . . . . . . . . ASTMA421
2. Low-relaxation wire. . . . . . . . . . ASTMA421
3. Strand . . . . . . . . . . . . . . . . . ASTMA416
4. Low-relaxation strand . . . . . . . . . ASTMA416
5. Bar . . . . . . . . . . . . . . . . . . ASTMA722
Exceptions:
1. Wire, strands and bars not specifically listed in
ASTM A 421, ASTM A 416 or ASTM A 722
are permitted, provided they conform to the
minimum requirements in ASTM A 421,
ASTM A 416 or ASTM A 722 and are
approved by the architect/engineer.
2. Bars and wires of less than 150 kips per square
inch (ksi) (1034 MPa) tensile strength and conforming
to ASTM A 82, ASTM A 510, ASTM
A 615, ASTM A 996 or ASTM A 706 are permitted
to be used as prestressed tendons, provided
that:
2.1. The stress relaxation properties have
been assessed by tests according to
ASTM E 328 for the maximum permissible
stress in the tendon.
2.2. Other nonstress-related requirements of
ACI 530/ASCE 5/TMS 402, Chapter 4,
addressing prestressing tendons are
met.

Corrosion protection. Corrosion protection for
prestressing tendons shall comply with the requirements of
ACI 530.1/ASCE 6/TMS 602, Article 2.4G. Corrosion protection
for prestressing anchorages, couplers and end
blocks shall comply with the requirements of ACI
530.1/ASCE 6/TMS 602, Article 2.4H. Corrosion protection
for carbon steel accessories used in exterior wall construction
or interior walls exposed to a mean relative
humidity exceeding 75 percent shall comply with either
Section 2103.13.7.2 or 2103.13.7.3. Corrosion protection
for carbon steel accessories used in interiorwalls exposed to
a mean relative humidity equal to or less than 75 percent
shall comply with either Section 2103.13.7.1, 2103.13.7.2
or 2103.13.7.3.

Mill galvanized. Mill galvanized coatings
shall be applied as follows:
1. For joint reinforcement, wall ties, anchors and
inserts, a minimum coating of 0.1 ounce per square
foot (31g/m2) complying with the requirements of
ASTM A 641 shall be applied.
2. For sheet metal ties and sheet metal anchors, a
minimum coating complying with Coating Designation
G-60 according to the requirements of
ASTM A 653 shall be applied.
3. For anchor bolts, steel plates or bars not exposed to
the earth, weather or a mean relative humidity
exceeding 75 percent, a coating is not required.

Hot-dipped galvanized. Hot-dipped galvanized
coatings shall be applied after fabrication as follows:
1. For joint reinforcement, wall ties, anchors and
inserts, a minimum coating of 1.5 ounces per
square foot (458 g/m2) complying with the requirements
of ASTM A 153, Class B shall be applied.
2. For sheet metal ties and anchors, the requirements
of ASTM A 153, Class B shall be met.
3. For steel plates and bars, the requirements of either
ASTM A 123 or ASTM A 153, Class B shall be
met.

Epoxy coatings. Carbon steel accessories
shall be epoxy coated as follows:
1. For joint reinforcement, the requirements of
ASTM A 884, Class A, Type 1 having a minimum
thickness of 7 mils (175 #m) shall be met.
2. For wire ties and anchors, the requirements of
ASTM A 899, Class C having a minimum thickness
of 20 mils (508 #m) shall be met.
3. For sheet metal ties and anchors, a minimum thickness
of 20 mils (508 #m) per surface shall be provided
or a minimum thickness in accordance with
the manufacturer’s specification shall be provided.

Tests. Where unidentified reinforcement is
approved for use, not less than three tension and three bending
tests shall be made on representative specimens of the
reinforcement from each shipment and grade of reinforcing
steel proposed for use in the work.

International Building Code 2103.13.1

Deformed reinforcing bars. Deformed reinforcing
bars shall conform to one of the following standards:
ASTMA615 for deformed and plain billet-steel bars
for concrete reinforcement; ASTM A 706 for low-alloy
steel deformed bars for concrete reinforcement; ASTM A
767 for zinc-coated reinforcing steel bars; ASTM A 775 for
epoxy-coated reinforcing steel bars; and ASTM A 996 for
rail and axle steel-deformed bars for concrete reinforcement.

International Building Code 2103.13.2

Joint reinforcement. Joint reinforcement shall
comply with ASTM A 951. The maximum spacing of
crosswires in ladder-type joint reinforcement and point of
connection of cross wires to longitudinal wires of truss-type
reinforcement shall be 16 inches (400 mm).

International Building Code 2103.13.3

Deformed reinforcing wire. Deformed reinforcing
wire shall conform to ASTM A 496.

International Building Code 2103.13.4

Wire fabric.Wire fabric shall conform toASTM
A 185 for plain steel-welded wire fabric for concrete reinforcement
or ASTM A 497 for welded deformed steel wire
fabric for concrete reinforcement.
2006 INTERNATIONAL BUILDING CODE 393
MASONRY

International Building Code 2103.13.5

Anchors, ties and accessories. Anchors, ties
and accessories shall conform to the following standards:
ASTM A 36 for structural steel; ASTM A 82 for plain steel
wire for concrete reinforcement; ASTM A 185 for plain
steel-welded wire fabric for concrete reinforcement;ASTM
A 240 for chromium and chromium-nickle stainless steel
plate, sheet and strip; ASTM A 307 Grade A for anchor
bolts; ASTM A 480 for flat rolled stainless and heat-resisting
steel plate, sheet and strip; and ASTM A 1008 for
cold-rolled carbon steel sheet.

International Building Code 2103.13.6

Prestressing tendons. Prestressing tendons
shall conform to one of the following standards:
1. Wire . . . . . . . . . . . . . . . . . . ASTMA421
2. Low-relaxation wire. . . . . . . . . . ASTMA421
3. Strand . . . . . . . . . . . . . . . . . ASTMA416
4. Low-relaxation strand . . . . . . . . . ASTMA416
5. Bar . . . . . . . . . . . . . . . . . . ASTMA722
Exceptions:
1. Wire, strands and bars not specifically listed in
ASTM A 421, ASTM A 416 or ASTM A 722
are permitted, provided they conform to the
minimum requirements in ASTM A 421,
ASTM A 416 or ASTM A 722 and are
approved by the architect/engineer.
2. Bars and wires of less than 150 kips per square
inch (ksi) (1034 MPa) tensile strength and conforming
to ASTM A 82, ASTM A 510, ASTM
A 615, ASTM A 996 or ASTM A 706 are permitted
to be used as prestressed tendons, provided
that:
2.1. The stress relaxation properties have
been assessed by tests according to
ASTM E 328 for the maximum permissible
stress in the tendon.
2.2. Other nonstress-related requirements of
ACI 530/ASCE 5/TMS 402, Chapter 4,
addressing prestressing tendons are
met.

International Building Code 2103.13.7

Corrosion protection. Corrosion protection for
prestressing tendons shall comply with the requirements of
ACI 530.1/ASCE 6/TMS 602, Article 2.4G. Corrosion protection
for prestressing anchorages, couplers and end
blocks shall comply with the requirements of ACI
530.1/ASCE 6/TMS 602, Article 2.4H. Corrosion protection
for carbon steel accessories used in exterior wall construction
or interior walls exposed to a mean relative
humidity exceeding 75 percent shall comply with either
Section 2103.13.7.2 or 2103.13.7.3. Corrosion protection
for carbon steel accessories used in interiorwalls exposed to
a mean relative humidity equal to or less than 75 percent
shall comply with either Section 2103.13.7.1, 2103.13.7.2
or 2103.13.7.3.

Mill galvanized. Mill galvanized coatings
shall be applied as follows:
1. For joint reinforcement, wall ties, anchors and
inserts, a minimum coating of 0.1 ounce per square
foot (31g/m2) complying with the requirements of
ASTM A 641 shall be applied.
2. For sheet metal ties and sheet metal anchors, a
minimum coating complying with Coating Designation
G-60 according to the requirements of
ASTM A 653 shall be applied.
3. For anchor bolts, steel plates or bars not exposed to
the earth, weather or a mean relative humidity
exceeding 75 percent, a coating is not required.

Hot-dipped galvanized. Hot-dipped galvanized
coatings shall be applied after fabrication as follows:
1. For joint reinforcement, wall ties, anchors and
inserts, a minimum coating of 1.5 ounces per
square foot (458 g/m2) complying with the requirements
of ASTM A 153, Class B shall be applied.
2. For sheet metal ties and anchors, the requirements
of ASTM A 153, Class B shall be met.
3. For steel plates and bars, the requirements of either
ASTM A 123 or ASTM A 153, Class B shall be
met.

Epoxy coatings. Carbon steel accessories
shall be epoxy coated as follows:
1. For joint reinforcement, the requirements of
ASTM A 884, Class A, Type 1 having a minimum
thickness of 7 mils (175 #m) shall be met.
2. For wire ties and anchors, the requirements of
ASTM A 899, Class C having a minimum thickness
of 20 mils (508 #m) shall be met.
3. For sheet metal ties and anchors, a minimum thickness
of 20 mils (508 #m) per surface shall be provided
or a minimum thickness in accordance with
the manufacturer’s specification shall be provided.

International Building Code 2103.13.7.1

Mill galvanized. Mill galvanized coatings
shall be applied as follows:
1. For joint reinforcement, wall ties, anchors and
inserts, a minimum coating of 0.1 ounce per square
foot (31g/m2) complying with the requirements of
ASTM A 641 shall be applied.
2. For sheet metal ties and sheet metal anchors, a
minimum coating complying with Coating Designation
G-60 according to the requirements of
ASTM A 653 shall be applied.
3. For anchor bolts, steel plates or bars not exposed to
the earth, weather or a mean relative humidity
exceeding 75 percent, a coating is not required.

International Building Code 2103.13.7.2

Hot-dipped galvanized. Hot-dipped galvanized
coatings shall be applied after fabrication as follows:
1. For joint reinforcement, wall ties, anchors and
inserts, a minimum coating of 1.5 ounces per
square foot (458 g/m2) complying with the requirements
of ASTM A 153, Class B shall be applied.
2. For sheet metal ties and anchors, the requirements
of ASTM A 153, Class B shall be met.
3. For steel plates and bars, the requirements of either
ASTM A 123 or ASTM A 153, Class B shall be
met.

International Building Code 2103.13.7.3

Epoxy coatings. Carbon steel accessories
shall be epoxy coated as follows:
1. For joint reinforcement, the requirements of
ASTM A 884, Class A, Type 1 having a minimum
thickness of 7 mils (175 #m) shall be met.
2. For wire ties and anchors, the requirements of
ASTM A 899, Class C having a minimum thickness
of 20 mils (508 #m) shall be met.
3. For sheet metal ties and anchors, a minimum thickness
of 20 mils (508 #m) per surface shall be provided
or a minimum thickness in accordance with
the manufacturer’s specification shall be provided.

International Building Code 2103.13.8

Tests. Where unidentified reinforcement is
approved for use, not less than three tension and three bending
tests shall be made on representative specimens of the
reinforcement from each shipment and grade of reinforcing
steel proposed for use in the work.

International Building Code 2103.2

Clay or shale masonry units. Clay or shale masonry
units shall conform to the following standards: ASTM C 34 for
structural clay load-bearingwall tile;ASTMC56 for structural
clay nonload-bearing wall tile; ASTM C 62 for building brick
(solid masonry units made from clay or shale); ASTM C 1088
for solid units of thin veneer brick; ASTM C 126 for
ceramic-glazed structural clay facing tile, facing brick and
solid masonry units; ASTM C 212 for structural clay facing
tile; ASTM C 216 for facing brick (solid masonry units made
from clay or shale); ASTM C 652 for hollow brick (hollow
masonry units made from clay or shale); andASTMC1405 for
glazed brick (single-fired solid brick units).
Exception: Structural clay tile for nonstructural use in fireproofing
of structural members and in wall furring shall not
be required to meet the compressive strength specifications.
The fire-resistance rating shall be determined in accordance
with ASTM E 119 and shall comply with the requirements
of Table 602.

International Building Code 2103.3

AAC masonry. AAC masonry units shall conform to
ASTM C 1386 for the strength class specified.

International Building Code 2103.4

Stone masonry units. Stone masonry units shall conform
to the following standards: ASTM C 503 for marble
building stone (exterior); ASTM C 568 for limestone building
stone; ASTM C 615 for granite building stone; ASTM C 616
for sandstone building stone; orASTMC629 for slate building
stone.

International Building Code 2103.5

Ceramic tile. Ceramic tile shall be as defined in, and
shall conform to the requirements of, ANSI A137.1.

International Building Code 2103.6

Glass unit masonry. Hollow glass units shall be partially
evacuated and have a minimum average glass face thickness
of 3/16 inch (4.8 mm). Solid glass-block units shall be
provided when required. The surfaces of units intended to be in
contact with mortar shall be treated with a polyvinyl butyral
coating or latex-based paint. Reclaimed units shall not be used.

International Building Code 2103.7

Second-hand units. Second-hand masonry units shall
not be reused unless they conform to the requirements of new
units. The units shall be of whole, sound materials and free
from cracks and other defects that will interfere with proper
laying or use. Old mortar shall be cleaned from the unit before
reuse.

International Building Code 2103.8

Mortar. Mortar for use in masonry construction shall
conform to ASTM C 270 and shall conform to the proportion
specifications of Table 2103.8(1) or the property specifications
of Table 2103.8(2). Type S or N mortar shall be used for glass
unit masonry. The amount ofwater used in mortar for glass unit
masonry shall be adjusted to account for the lack of absorption.
Retempering of mortar for glass unit masonry shall not be permitted
after initial set. Unused mortar shall be discarded within
21/2 hours after initial mixing, except that unused mortar for
glass unit masonry shall be discarded within 11/2 hours after initial
mixing.

International Building Code 2103.9

Surface-bonding mortar. Surface-bonding mortar
shall comply with ASTM C 887. Surface bonding of concrete
masonry units shall comply with ASTM C 946.