The construction documents shall show all of the items required by this code including the following:
- Specified size, grade, type and location of reinforcement, anchors and wall ties.
- Reinforcing bars to be welded and welding procedure.
- Size and location of structural elements.
- Provisions for dimensional changes resulting from elastic deformation, creep, shrinkage, temperature and moisture.
- Loads used in the design of masonry.
- Specified compressive strength of masonry at stated ages or stages of construction for which masonry is designed, except where specifically exempted by this code.
- Details of anchorage of masonry to structural members, frames and other construction, including the type, size and location of connectors.
- Size and permitted location of conduits, pipes and sleeves.
- The minimum level of testing and inspection as defined in Chapter 17, or an itemized testing and inspection program that meets or exceeds the requirements of Chapter 17.
The following terms are defined in Chapter 2:
- Ashlar masonry.
- Coursed ashlar.
- Glass unit masonry.
- Plain masonry.
- Random ashlar.
- Reinforced masonry.
- Solid masonry.
- Unreinforced (plain) masonry.
- Detailed plain masonry shear wall.
- Intermediate prestressed masonry shear wall.
- Intermediate reinforced masonry shear wall.
- Ordinary plain masonry shear wall.
- Ordinary plain prestressed masonry shear wall.
- Ordinary reinforced masonry shear wall.
- Special prestressed masonry shear wall.
- Special reinforced masonry shear wall.
SPECIFIED COMPRESSIVE STRENGTH OF MASONRY, f' m.
- Cavity wall.
- Composite wall.
- Dry-stacked, surface-bonded wall.
- Masonry-bonded hollow wall.
- Parapet wall.
|db||=||Diameter of reinforcement, inches (mm).|
|Fs||=||Allowable tensile or compressive stress in reinforcement, psi (MPa).|
|fr||=||Modulus of rupture, psi (MPa).|
|f'AAC||=||Specified compressive strength of AAC masonry, the minimum compressive strength for a class of AAC masonry as specified in ASTM C 1386, psi (MPa).|
|f 'm||=||Specified compressive strength of masonry at age of28 days, psi (MPa).|
|f 'mi||=||Specified compressive strength of masonry at the time of prestress transfer, psi (MPa).|
|K||=||The lesser of the masonry cover, clear spacing between adjacent reinforcement, or five times db, inches (mm).|
|Ls||=||Distance between supports, inches (mm).|
|ld||=||Required development length or lap length of reinforcement, inches (mm).|
|P||=||The applied load at failure, pounds (N).|
|St||=||Thickness of the test specimen measured parallel to the direction of load, inches (mm).|
|Sw||=||Width of the test specimen measured parallel to the loading cylinder, inches (mm).|
Clay or shale masonry units shall conform to the following standards: ASTM C 34 for structural clay load-bearing wall tile; ASTM C 56 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) or ASTM C 1405 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 or UL 263 and shall comply with the requirements of Table 602.
CERAMIC TILE MORTAR COMPOSITIONS
|Walls||Scratchcoat||1 cement;1/5 hydrated lime; |
4 dry or 5 damp sand
|Setting bed and leveling |
|1 cement;1/2 hydrated lime;|
5 damp sand to 1 cement1 hydrated lime, 7 damp sand
|Floors||Setting bed||1 cement;1/10 hydrated lime; |
5 dry or 6 damp sand; or 1cement; 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
- Units are sampled and tested to verify compliance with ASTM C 62, ASTM C 216 or ASTM C 652.
- Thickness of bed joints does not exceed 5/8 inch (15.9 mm).
| NET AREA COMPRESSIVE STRENGTH |
OF CLAY MASONRY UNITS (psi)
| NET AREA |
|Type M or S mortar||Type N mortar|
For SI: 1 pound per square inch = 0.00689 MPa.
- Units are sampled and tested to verify compliance with ASTM C 55 or ASTM C 90.
- Thickness of bed joints does not exceed 5/8 inch (15.9 mm).
| NET AREA COMPRESSIVE |
STRENGTH OF CONCRETE MASONRY
| NET AREA COMPRESSIVE |
STRENGTH OF MASONRY (psi)a
|Type M or S mortar||Type N mortar|
For SI: 1 inch = 25.4 mm, 1 pound per square inch = 0.00689 MPa.
- For units less than 4 inches in height, 85 percent of the values listed.
- Units conform to ASTM C 1386.
- Thickness of bed joints does not exceed 1/8 inch (3.2 mm).
The minimum length of lap splices for reinforcing bars in tension or compression, ld, shall be
For SI: ld = 0.29db fs
but not less than 12 inches (305 mm). In no case shall the length of the lapped splice be less than 40 bar diameters.
db = Diameter of reinforcement, inches (mm).
fs = Computed stress in reinforcement due to design loads, psi (MPa).
In regions of moment where the design tensile stresses in the reinforcement are greater than 80 percent of the allowable steel tension stress, Fs, the lap length of splices shall be increased not less than 50 percent of the minimum required length. Other equivalent means of stress transfer to accomplish the same 50 percent increase shall be permitted. Where epoxy coated bars are used, lap length shall be increased by 50 percent.
Modify Section 188.8.131.52 as follows:
184.108.40.206 Splices of reinforcement. Lap splices, welded splices or mechanical splices are permitted in accordance with the provisions of this section. All welding shall conform to AWS D1.4. Welded splices shall be of ASTM A 706 steel reinforcement. Reinforcement larger than No. 9 (M #29) shall be spliced using mechanical connections in accordance with Section 220.127.116.11.3.
Add the following to Chapter 2:
2.3.7 Maximum bar size. The bar diameter shall not exceed one-eighth of the nominal wall thickness and shall not exceed one-quarter of the least dimension of the cell, course or collar joint in which it is placed.
The design of masonry structures using strength design shall comply with Section 2106 and the requirements of Chapters 1 and 3 of TMS 402/ACI 530/ASCE 5, except as modified by Sections 2108.2 through 2108.3.
Exception: AAC masonry shall comply with the requirements of Chapters 1 and 8 of TMS 402/ACI 530/ASCE 5.
Modify the second paragraph of Section 18.104.22.168 as follows:
The required development length of reinforcement shall be determined by Equation (3-16), but shall not be less than 12 inches (305 mm) and need not be greater than 72 db.
Modify items (c) and (d) of Section 22.214.171.124 as follows:
126.96.36.199 (c). A welded splice shall have the bars butted and welded to develop at least 125 percent of the yield strength, fy, of the bar in tension or compression, as required. Welded splices shall be of ASTM A 706 steel reinforcement. Welded splices shall not be permitted in plastic hinge zones of intermediate or special reinforced walls or special moment frames of masonry.
188.8.131.52 (d). Mechanical splices shall be classified as Type 1 or 2 according to Section 184.108.40.206 of ACI 318. Type 1 mechanical splices shall not be used within a plastic hinge zone or within a beam-column joint of intermediate or special reinforced masonry shear walls or special moment frames. Type 2 mechanical splices are permitted in any location within a member.
The use of empirical design of masonry shall be limited as noted in Section 5.1.2 of TMS 402/ACI 530/ASCE 5. The use of dry-stacked, surface-bonded masonry shall be prohibited in Risk Category IV structures. In buildings that exceed one or more of the limitations of Section 5.1.2 of TMS 402/ACI 530/ASCE 5, masonry shall be designed in accordance with the engineered design provisions of Section 2101.2.1, 2101.2.2 or 2101.2.3 or the foundation wall provisions of Section 1807.1.5.
Section 220.127.116.11 of TMS 402/ACI 530/ASCE 5 shall be modified as follows:
18.104.22.168 Wind — Empirical requirements shall not apply to the design or construction of masonry for buildings, parts of buildings, or other structures to be located in areas where Vasd as determined in accordance with Section 1609.3.1 of the International Building Code exceeds 110 mph.
Dry-stacked, surface-bonded concrete masonry walls shall be of adequate strength and proportions to support all superimposed loads without exceeding the allowable stresses listed in Table 2109.2.1. Allowable stresses not specified in Table 2109.2.1 shall comply with the requirements of TMS 402/ACI 530/ASCE 5.
The modulus of rupture shall be determined by the equation:
where, for the purposes of this section only:
Sw = Width of the test specimen measured parallel to the loading cylinder, inches (mm).
fr = Modulus of rupture, psi (MPa).
Ls = Distance between supports, inches (mm).
St = Thickness of the test specimen measured parallel to the direction of load, inches (mm).
P = The applied load at failure, pounds (N).
Solid or hollow approved glass block shall not be used in fire walls, party walls, fire barriers, fire partitions or smoke barriers, or for load-bearing construction. Such blocks shall be erected with mortar and reinforcement in metal channel-type frames, structural frames, masonry or concrete recesses, embedded panel anchors as provided for both exterior and interior walls or other approved joint materials. Wood strip framing shall not be used in walls required to have a fire-resistance rating by other provisions of this code.
- Glass-block assemblies having a fire protection rating of not less than 3/4 hour shall be permitted as opening protectives in accordance with Section 716 in fire barriers, fire partitions and smoke barriers that have a required fire-resistance rating of 1 hour or less and do not enclose exit stairways, exit ramps or exit passageways.
- Glass-block assemblies as permitted in Section 404.6, Exception 2.
The firebox of a concrete or masonry fireplace shall have a minimum depth of 20 inches (508 mm). The throat shall not be less than 8 inches (203 mm) above the fireplace opening. The throat opening shall not be less than 4 inches (102 mm) in depth. The cross-sectional area of the passageway above the firebox, including the throat, damper and smoke chamber, shall not be less than the cross-sectional area of the flue.
Exception: Rumford fireplaces shall be permitted provided that the depth of the fireplace is at least 12 inches (305 mm) and at least one-third of the width of the fireplace opening, and the throat is at least 12 inches (305 mm) above the lintel, and at least 1/20 the cross-sectional area of the fireplace opening.
The minimum thickness of hearth extensions shall be 2 inches (51 mm).
Exception: When the bottom of the firebox opening is raised at least 8 inches (203 mm) above the top of the hearth extension, a hearth extension of not less than 3/8-inch-thick (9.5 mm) brick, concrete, stone, tile or other approved noncombustible material is permitted.
Any portion of a masonry fireplace located in the interior of a building or within the exterior wall of a building shall have a clearance to combustibles of not less than 2 inches (51 mm) from the front faces and sides of masonry fireplaces and not less than 4 inches (102 mm) from the back faces of masonry fireplaces. The airspace shall not be filled, except to provide fireblocking in accordance with Section 2111.12.
- Masonry fireplaces listed and labeled for use in contact with combustibles in accordance with UL 127 and installed in accordance with the manufacturer's installation instructions are permitted to have combustible material in contact with their exterior surfaces.
- When masonry fireplaces are constructed as part of masonry or concrete walls, combustible materials shall not be in contact with the masonry or concrete walls less than 12 inches (306 mm) from the inside surface of the nearest firebox lining.
- Exposed combustible trim and the edges of sheathing materials, such as wood siding, flooring and drywall, are permitted to abut the masonry fireplace sidewalls and hearth extension, in accordance with Figure 2111.11, provided such combustible trim or sheathing is a minimum of 12 inches (306 mm) from the inside surface of the nearest firebox lining.
- Exposed combustible mantels or trim is permitted to be placed directly on the masonry fireplace front surrounding the fireplace opening, provided such combustible materials shall not be placed within 6 inches (153 mm) of a fireplace opening. Combustible material directly above and within 12 inches (305 mm) of the fireplace opening shall not project more than 1/8 inch (3.2 mm) for each 1-inch (25 mm) distance from such opening. Combustible materials located along the sides of the fireplace opening that project more than 11/2 inches (38 mm) from the face of the fireplace shall have an additional clearance equal to the projection.
Masonry heaters shall be installed in accordance with this section and comply with one of the following:
Combustible materials shall not be placed within 36 inches (765 mm) of the outside surface of a masonry heater in accordance with NFPA 211, Section 8-7 (clearances for solid fuel-burning appliances), and the required space between the heater and combustible material shall be fully vented to permit the free flow of air around all heater surfaces.
- When the masonry heater wall thickness is at least 8 inches (203 mm) thick of solid masonry and the wall thickness of the heat exchange channels is at least 5 inches (127 mm) thick of solid masonry, combustible materials shall not be placed within 4 inches (102 mm) of the outside surface of a masonry heater. A clearance of at least 8 inches (203 mm) shall be provided between the gas-tight capping slab of the heater and a combustible ceiling.
- Masonry heaters listed and labeled in accordance with UL 1482 and installed in accordance with the manufacturer's instructions.
- The net free area of the arrestor shall not be less than four times the net free area of the outlet of the chimney flue it serves.
- The arrestor screen shall have heat and corrosion resistance equivalent to 19-gage galvanized steel or 24-gage stainless steel.
- Openings shall not permit the passage of spheres having a diameter greater than 1/2 inch (12.7 mm) nor block the passage of spheres having a diameter less than 3/8 inch (9.5 mm).
- The spark arrestor shall be accessible for cleaning and the screen or chimney cap shall be removable to allow for cleaning of the chimney flue.
Flue lining systems shall comply with one of the following:
- Clay flue lining complying with the requirements of ASTM C 315.
- Listed chimney lining systems complying with UL 1777.
- Factory-built chimneys or chimney units listed for installation within masonry chimneys.
- Other approved materials that will resist corrosion, erosion, softening or cracking from flue gases and condensate at temperatures up to 1,800°F (982°C).
Concrete and masonry chimneys shall be lined with an approved medium-duty refractory brick a minimum of 41/2 inches (114 mm) thick laid on the 41/2-inch bed (114 mm) in an approved medium-duty refractory mortar.
The lining shall start 2 feet (610 mm) or more below the lowest chimney connector entrance. Chimneys terminating 25 feet (7620 mm) or less above a chimney connector entrance shall be lined to the top.
Clay flue liners shall be installed in accordance with ASTM C 1283 and extend from a point not less than 8 inches (203 mm) below the lowest inlet or, in the case of fireplaces, from the top of the smoke chamber to a point above the enclosing walls. The lining shall be carried up vertically, with a maximum slope no greater than 30 degrees (0.52 rad) from the vertical.
Clay flue liners shall be laid in medium-duty nonwater-soluble refractory mortar conforming to ASTM C 199 with tight mortar joints left smooth on the inside and installed to maintain an air space or insulation not to exceed the thickness of the flue liner separating the flue liners from the interior face of the chimney masonry walls. Flue lining shall be supported on all sides. Only enough mortar shall be placed to make the joint and hold the liners in position.
When two or more flues are located in the same chimney, masonry wythes shall be built between adjacent flue linings. The masonry wythes shall be at least 4 inches (102 mm) thick and bonded into the walls of the chimney.
Exception: When venting only one appliance, two flues are permitted to adjoin each other in the same chimney with only the flue lining separation between them. The joints of the adjacent flue linings shall be staggered at least 4 inches (102 mm).
Chimney flues shall not be smaller in area than the area of the connector from the appliance. Chimney flues connected to more than one appliance shall not be less than the area of the largest connector plus 50 percent of the areas of additional chimney connectors.
|FLUE SIZE, INSIDE DIAMETER |
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm2.
- Flue sizes are based on ASTM C 315.
|FLUE SIZE, OUTSIDE NOMINAL|
|4.5 × 8.5||23|
|4.5 × 13||34|
|8 × 8||42|
|8.5 × 8.5||49|
|8 × 12||67|
|8.5 × 13||76|
|12 × 12||102|
|8.5 × 18||101|
|12 × 16||131|
|13 × 18||173|
|16 × 16||181|
|16 × 20||222|
|18 × 18||233|
|20 × 20||298|
|20 × 24||335|
|24 × 24||431|
For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm2.
Cleanout openings shall be provided within 6 inches (152 mm) of the base of each flue within every masonry chimney. The upper edge of the cleanout shall be located at least 6 inches (152 mm) below the lowest chimney inlet opening. The height of the opening shall be at least 6 inches (152 mm). The cleanout shall be provided with a noncombustible cover.
Any portion of a masonry chimney located in the interior of the building or within the exterior wall of the building shall have a minimum airspace clearance to combustibles of 2 inches (51 mm). Chimneys located entirely outside the exterior walls of the building, including chimneys that pass through the soffit or cornice, shall have a minimum airspace clearance of 1 inch (25 mm). The airspace shall not be filled, except to provide fireblocking in accordance with Section 2113.20.
- Masonry chimneys equipped with a chimney lining system listed and labeled for use in chimneys in contact with combustibles in accordance with UL 1777, and installed in accordance with the manufacturer's instructions, are permitted to have combustible material in contact with their exterior surfaces.
- Where masonry chimneys are constructed as part of masonry or concrete walls, combustible materials shall not be in contact with the masonry or concrete wall less than 12 inches (305 mm) from the inside surface of the nearest flue lining.
- Exposed combustible trim and the edges of sheathing materials, such as wood siding, are permitted to abut the masonry chimney sidewalls, in accordance with Figure 2113.19, provided such combustible trim or sheathing is a minimum of 12 inches (305 mm) from the inside surface of the nearest flue lining. Combustible material and trim shall not overlap the corners of the chimney by more than 1 inch (25 mm).