Code of Massachusetts Regulations › 780 CMR - STATE BOARD OF BUILDING REGULATIONS AND STANDARDS › Chapter 7 - Fire and Smoke Protection Features › Section 720 - PRESCRIPTIVE FIRE RESISTANCE › Subsection 720.1 - General

Current through Register 1525, July 5, 2024
The provisions of this section contain prescriptive details
				  of fire-resistance-rated building elements, components or assemblies. The
				  materials of construction listed in Tables 720.1(1), 720.1(2), and 720.1(3)
				  shall be assumed to have the
fire-resistance ratings
prescribed therein. Where materials that change the capacity for heat
				  dissipation are incorporated into a fire-resistance-rated assembly, fire test
				  results or other substantiating data shall be made available to the
building official
to show that the required
				  fire-resistance-rating time period is not reduced.
TABLE 720.1(1) MINIMUM PROTECTION OF STRUCTURAL PARTS
				  BASED ON TIME PERIODS FOR VARIOUS NONCOMBUSTIBLE INSULATING
				  MATERIALSm
STRUCTURAL PARTS TO BE
							 PROTECTED
ITEM NUMBER
INSULATING MATERIAL USED
MINIMUM THICKNESS OF INSULATING
							 MATERIAL FOR THE FOLLOWING FIRE-RESISTANCE PERIODS (inches)
4 hour
3 hour
2 hour
1 hour
1. Steel columns and all of primary
							 trusses
1-1.1
Carbonate, lightweight and sand-lightweight aggregate
							 concrete, members 6'' × 6'' or greater (not including sandstone, granite
							 and siliceous gravel).a
21/2
2
11/2
1
1-1.2
Carbonate, lightweight and sand-lightweight aggregate
							 concrete, members 8'' × 8'' or greater (not including sandstone, granite
							 and siliceous gravel).a
2
11/2
1
1
1-1.3
Carbonate, lightweight and sand-lightweight aggregate
							 concrete, members 12'' ×12'' or greater (not including sandstone, granite
							 and siliceous gravel).a
11/2
1
1
1
1-1.4
Siliceous aggregate concrete and concrete excluded in
							 Item 1-1.1, members 6'' × 6'' or greater.a
3
2
11/2
1
1-1.5
Siliceous aggregate concrete and concrete excluded in
							 Item 1-1.1, members 8'' × 8'' or greater.a
21/2
2
1
1
1-1.6
Siliceous aggregate concrete and concrete excluded in
							 Item 1-1.1, members 12'' × 12'' or
							 greater.a
2
1
1
1
1-2.1
Clay or shale brick with brick and mortar
							 fill.a
33/4
-
-
21/4
1-3.1
4'' hollow clay tile in two 2'' layers;
							 1/2'' mortar between tile and
							 column; 3/8'' metal mesh
							 0.046' wire diameter in horizontal joints; tile
							 fill.a
4
-
-
-
1-3.2
2' hollow clay tile;
							 3/4'' mortar between tile and
							 column; 3/8'' metal mesh
							 0.046'' wire diameter in horizontal joints; limestone concrete fill;a plastered
							 with 3/4'' gypsum
							 plaster.
3
-
-
-
1-3.3
2'' hollow clay tile with outside wire ties 0.08''
							 diameter at each course of tile or
							 3/8'' metal mesh 0.046''
							 diameter wire in horizontal joints; limestone or trap-rock concrete filla
							 extending 1'' outside column on all sides.
-
-
3
-
1-3.4
2'' hollow clay tile with outside wire ties 0.08''
							 diameter at each course of tile with or without concrete fill;
							 3/4'' mortar between tile and
							 column.
-
-
-
2
1-4.1
Cement plaster over metal lath wire tied to
							 3/4'' cold-rolled vertical
							 channels with 0.049'' (No.18 B.W. gage) wire ties spaced 3'' to 6'' on center.
							 Plaster mixed 1:2 1/2 by
							 volume, cement to sand.
-
-
21/2b
7/8
1-5.1
Vermiculite concrete, 1:4 mix by volume over
							 paperbacked wire fabric lath wrapped directly around column with additional 2''
							 × 2'' 0.065'/0.065'' (No. 16/16 B.W. gage) wire fabric placed
							 3/4'' from outer concrete
							 surface. Wire fabric tied with 0.049'' (No. 18 B.W. gage) wire spaced 6'' on
							 center for inner layer and 2'' on center for outer layer.
2
-
-
-
1-6.1
Perlite or vermiculite gypsum plaster over metal lath
							 wrapped around column and furred
							 11/4'' from column flanges.
							 Sheets lapped at ends and tied at 6'' intervals with 0.049'' (No. 18 B.W. gage)
							 tie wire. Plaster pushed through to flanges.
11/2
1
-
-
1-6.2
Perlite or vermiculite gypsum plaster over self-furring
							 metal lath wrapped directly around column, lapped 1'' and tied at 6'' intervals
							 with 0.049'' (No. 18 B.W. gage) wire.
13/4
13/8
1
-
1-6.3
Perlite or vermiculite gypsum plaster on metal lath
							 applied to 3/4'' cold-rolled
							 channels spaced 24'' apart vertically and wrapped flatwise around column.
11/2
-
-
-
1-6.4
Perlite or vermiculite gypsum plaster over two layers
							 of 1/2'' plain full-length
							 gypsum lath applied tight to column flanges. Lath wrapped with 1'' hexagonal
							 mesh of No. 20 gage wire and tied with doubled 0.035'' diameter (No. 18 B.W.
							 gage) wire ties spaced 23'' on center. For three-coat work, the plaster mix for
							 the second coat shall not exceed 100 pounds of gypsum to
							 21/2 cubic feet of aggregate
							 for the 3-hour system.
21/2
2
-
-
1. Steel columns and all of primary trusses
							 (continued)
1-6.5
Perlite or vermiculate gypsum plaster over one layer of
							 1/2'' plain full-length
							 gypsum lath applied tight to column flanges. Lath tied with doubled 0.049''
							 (No. 18 B.W. gage) wire ties spaced 23'' on center and scratch coat wrapped
							 with 1'' hexagonal mesh 0.035'' (No. 20 B.W. gage) wire fabric. For three-coat
							 work, the plaster mix for the second coat shall not exceed 100 pounds of gypsum
							 to 21/2cubic feet of
							 aggregate.
-
2
-
-
1-7.1
Multiple layers of
							 1/2'' gypsum
							 wallboardc adhesivelyd
							 secured to column flanges and successive layers. Wallboard applied without
							 horizontal joints. Corner edges of each layer staggered. Wallboard layer below
							 outer layer secured to column with doubled 0.049'' (No. 18 B.W. gage) steel
							 wire ties spaced 15'' on center. Exposed corners taped and treated.
-
-
2
1
1-7.2
Three layers of
							 5/8'' Type X gypsum
							 wallboard.c First and second layer held in place by
							 1/8'' diameter by
							 13/8'' long ring shank nails
							 with 5/16'' diameter heads
							 spaced 24'' on center at corners. Middle layer also secured with metal straps
							 at mid-height and 18'' from each end, and by metal corner bead at each corner
							 held by the metal straps. Third layer attached to corner bead with 1'' long
							 gypsum wallboard screws spaced 12'' on center.
-
-
17/8
-
1-7.3
Three layers of
							 5/8'' Type X gypsum
							 wallboard,c each layer screw attached to
							 15/8'' steel studs 0.018''
							 thick (No. 25 carbon sheet steel gage) at each corner of column. Middle layer
							 also secured with 0.049'' (No. 18 B.W.gage) double-strand steel wire ties, 24''
							 on center. Screws are No. 6 by 1'' spaced 24'' on center for inner layer, No. 6
							 by 15/8'' spaced 12'' on
							 center for middle layer and No. 8 by
							 21/4'' spaced 12'' on center
							 for outer layer.
-
17/8
-
-
1-8.1
Wood-fibered gypsum plaster mixed 1:1 by weight
							 gypsum-to-sand aggregate applied over metal lath. Lath lapped 1'' and tied 6''
							 on center at all end, edges and spacers with 0.049'' (No. 18 B.W. gage) steel
							 tie wires. Lath applied over
							 1/2'' spacers made of
							 3/4'' furring channel with
							 2'' legs bent around each corner. Spacers located 1'' from top and bottom of
							 member and a maximum of 40'' on center and wire tied with a single strand of
							 0.049'' (No. 18 B.W. gage) steel tie wires. Corner bead tied to the lath at 6''
							 on center along each corner to provide plaster thickness.
-
-
15/8
-
1-9.1
Minimum W8x 35 wide flange steel column (w/d > =
							 0.75) with each web cavity filled even with the flange tip with normal weight
							 carbonate or siliceous aggregate concrete (3,000 psi minimum compressive
							 strength with 145 pcf ± 3 pcf unit weight). Reinforce the concrete in
							 each web cavity with a minimum No. 4 deformed reinforcing bar installed
							 vertically and centered in the cavity, and secured to the column web with a
							 minimum No. 2 horizontal deformed reinforcing bar welded to the web every 18''
							 on center vertically. As an alternative to the No. 4 rebar,
							 3/4'' diameter by 3'' long
							 headed studs, spaced at 12'' on center vertically, shall be welded on each side
							 of the web midway between the column flanges.
-
-
-
See Note n
2. Webs or flanges of steel beams and
							 girders
2-1.1
Carbonate, lightweight and sand-lightweight aggregate
							 concrete (not including sandstone, granite and siliceous gravel) with 3'' or
							 finer metal mesh placed 1'' from the finished surface anchored to the top
							 flange and providing not less than 0.025 square inch of steel area per foot in
							 each direction.
2
11/2
1
1
2-1.2
Siliceous aggregate concrete and concrete excluded in
							 Item 2-1.1 with 3'' or finer metal mesh placed 1'' from the finished surface
							 anchored to the top flange and providing not less than 0.025 square inch of
							 steel area per foot in each direction.
21/2
2
11/2
1
2-2.1
Cement plaster on metal lath attached to
							 3/4'' cold-rolled channels
							 with 0.04'' (No. 18 B.W. gage) wire ties spaced 3'' to 6'' on center. Plaster
							 mixed 1:2 1/2 by volume,
							 cement to sand.
-
-
21/2b
7/8
2. Webs or flanges of steel beams and
							 girders (continued)
2-3.1
Vermiculite gypsum plaster on a metal lath cage, wire
							 tied to 0.165'' diameter (No. 8 B.W. gage) steel wire hangers wrapped around
							 beam and spaced 16'' on center. Metal lath ties spaced approximately 5'' on
							 center at cage sides and bottom.
-
7/8
-
-
2-4.1
Two layers of
							 5/8'' Type X gypsum
							 wallboardc are attached to U-shaped brackets spaced 24'' on center. 0.018''
							 thick (No. 25 carbon sheet steel gage)
							 15/8'' deep by 1'' galvanized
							 steel runner channels are first installed parallel to and on each side of the
							 top beam flange to provide a
							 1/2'' clearance to the
							 flange. The channel runners are attached to steel deck or concrete floor
							 construction with approved fasteners spaced 12'' on center. U-shaped brackets
							 are formed from members identical to the channel runners. At the bent portion
							 of the U-shaped bracket, the flanges of the channel are cut out so that
							 15/8'' deep corner channels
							 can be inserted without attachment parallel to each side of the lower flange.
							 As an alternate, 0.021'' thick (No. 24 carbon sheet steel gage) 1'' × 2''
							 runner and corner angles may be used in lieu of channels, and the web cutouts
							 in the U-shaped brackets may be omitted. Each angle is attached to the bracket
							 with 1/2''-long No. 8
							 self-drilling screws. The vertical legs of the U-shaped bracket are attached to
							 the runners with one 1/2''
							 long No. 8 self-drilling screw. The completed steel framing provides a
							 21/8'' and
							 11/2'' space between the
							 inner layer of wallboard and the sides and bottom of the steel beam,
							 respectively. The inner layer of wallboard is attached to the top runners and
							 bottom corner channels or corner angles with
							 11/4''-long No. 6
							 self-drilling screws spaced 16'' on center. The outer layer of wallboard is
							 applied with 13/4''-long No.
							 6 self-drilling screws spaced 8'' on center. The bottom corners are reinforced
							 with metal corner beads.
-
-
11/4
-
2-4.2
Three layers of
							 5/8'' Type X gypsum
							 wallboardc attached to a steel suspension system as described immediately above
							 utilizing the 0.018'' thick (No. 25 carbon sheet steel gage) 1'' × 2''
							 lower corner angles. The framing is located so that a
							 21/8'' and 2'' space is
							 provided between the inner layer of wallboard and the sides and bottom of the
							 beam, respectively. The first two layers of wallboard are attached as described
							 immediately above. A layer of 0.035'' thick (No. 20 B.W. gage) 1'' hexagonal
							 galvanized wire mesh is applied under the soffit of the middle layer and up the
							 sides approximately 2''. The mesh is held in position with the No. 6
							 15/8''-long screws installed
							 in the vertical leg of the bottom corner angles. The outer layer of wallboard
							 is attached with No. 6
							 21/4''-long screws spaced 8''
							 on center. One screw is also installed at the mid-depth of the bracket in each
							 layer. Bottom corners are finished as described above.
-
17/8
-
-
3. Bonded pretensioned reinforcement in
							 prestressed concretee
3-1.1
Carbonate, lightweight, sand-lightweight and
							 siliceousf aggregate concrete
4g
3g
21/2
11/2
Beams or girders
Solid slabsh
2
11/2
1
4. Bonded or unbonded post-tensioned
							 tendons in prestressed concretee, i
4-1.1
Carbonate, lightweight, sand-lightweight and
							 siliceousf aggregate concrete
Unrestrained members:
Solid slabsh
-
2
11/2
-
Beams and girdersj
8'' wide
41/2
21/2
13/4
greater than 12'' wide
3
21/2
2
11/2
4-1.2
Carbonate, lightweight, sand-lightweight and siliceous
							 aggregate
Restrained members:k
Solid slabsh
11/4
1
3/4
-
Beams and girdersj
8'' wide
21/2
2
13/4
-
greater than 12'' wide
2
13/4
11/2
-
5. Reinforcing steel in reinforced concrete
							 columns, beams girders and trusses
5-1.1
Carbonate, lightweight and sand-lightweight aggregate
							 concrete, members 12'' or larger, square or round. (Size limit does not apply
							 to beams and girders monolithic with floors.)
11/2
11/2
11/2
11/2
Siliceous aggregate concrete, members 12'' or larger,
							 square or round. (Size limit does not apply to beams and girders monolithic
							 with floors.)
2
11/2
11/2
11/2
6. Reinforcing steel in reinforced
							 concrete joistsl
6-1.1
Carbonate, lightweight and sand-lightweight aggregate
							 concrete.
11/4
11/4
1
3/4
6-1.2
Siliceous aggregate concrete.
13/4
11/2
1
3/4
7. Reinforcing and tie rods in floor and
							 roof slabsl
7-1.1
Carbonate, lightweight and sand-lightweight aggregate
							 concrete
1
1
3/4
3/4
7-1.2
Carbonate, lightweight and sand-lightweight aggregate
							 concrete
11/4
1
1
3/4
For SI: 1 inch = 25.4 mm, 1 square inch = 645.2
								mm2, 1 cubic foot = 0.0283
								m3, 1 pound per cubic foot = 16.02
								kg/m3.
a. Reentrant parts of protected members to be
								filled solidly.
b. Two layers of equal thickness with a
								3/4-inch airspace between.
c. For all of the construction with gypsum
								wallboard described in Table 720.1(1), gypsum base for veneer plaster of the
								same size, thickness and core type shall be permitted to be substituted for
								gypsum wallboard, provided attachment is identical to that specified for the
								wallboard and the joints on the face layer are reinforced, and the entire
								surface is covered with a minimum of
								1/16-inch gypsum veneer
								plaster.
d. An approved adhesive qualified under ASTM E 119
								or UL 263.
e. Where lightweight or sand-lightweight concrete
								having an oven-dry weight of 110 pounds per cubic foot or less is used, the
								tabulated minimum cover shall be permitted to be reduced 25 percent, except
								that in no case shall the cover be less than
								3/4 inch in slabs or
								11/2 inches in beams or
								girders.
f. For solid slabs of siliceous aggregate concrete,
								increase tendon cover 20 percent.
g. Adequate provisions against spalling shall be
								provided by U-shaped or hooped stirrups spaced not to exceed the depth of the
								member with a clear cover of 1 inch.
h. Prestressed slabs shall have a thickness not
								less than that required in Table 720.1(3) for the respective fire-resistance
								time period
i. Fire coverage and end anchorages shall be as
								follows: Cover to the prestressing steel at the anchor shall be
								1/2 inch greater than that
								required away from the anchor. Minimum cover to steel-bearing plate shall be 1
								inch in beams and 3/4 inch in
								slabs.
j. For beam widths between 8 inches and 12 inches,
								cover thickness shall be permitted to be determined by interpolation.
k. Interior spans of continuous slabs, beams and
								girders shall be permitted to be considered restrained.
l. For use with concrete slabs having a comparable
								fire endurance where members are framed into the structure in such a manner as
								to provide equivalent performance to that of monolithic concrete construction.
m. Generic fire-resistance ratings (those not
								designated as PROPRIETARY* in the listing) in GA 600 shall be accepted as if
								herein listed.
n. No additional insulating material is required on
								the exposed outside face of the column flange to achieve a 1-hour
								fire-resistance rating.
TABLE 720.1(2) RATED FIRE-RESISTANCE PERIODS FOR
				  VARIOUS WALLS AND PARTITIONS a, o, p
MATERIAL
ITEM NUMBER
CONSTRUCTION
MINIMUM FINISHED THICKNESS
							 FACE-TO-FACEb (inches)
4 hours
3 hours
2 hours
1 hour
1. Brick of clay or shale
1-1.1
Solid brick of clay or
							 shalec.
6
4.9
3.8
2.7
1-1.2
Hollow brick, not filled.
5.0
4.3
3.4
2.3
1-1.3
Hollow brick unit wall, grout or filled with perlite
							 vermiculite or expanded shale aggregate.
6.6
5.5
4.4
3.0
1-2.1
4" nominal thick units at least 75 percent solid
							 backed with a hat-shaped metal furring channel
							 3/4 " thick formed from
							 0.021" sheet metal attached to the brick wall on 24" centers with approved
							 fasteners, and 1 /2" Type X
							 gypsum wallboard attached to the metal furring strips with 1"-long Type S
							 screws spaced 8" on center.
-
-
5d
-
2. Combination of clay brick and
							 load-bearing hollow clay tile
2-1.1
4" solid brick and 4" tile (at least 40 percent
							 solid).
-
8
-
-
2-1.2
4" solid brick and 8" tile (at least 40 percent
							 solid).
12
-
-
-
3. Concrete masonry units
3-1.1f, g
Expanded slag or pumice.
4.7
4.0
3.2
2.1
3-1.2f, g
Expanded clay, shale or slate.
5.1
4.4
3.6
2.6
3-1.3f
Limestone, cinders or air-cooled slag.
5.9
5.0
4.0
2.7
3-1.4f, g
Calcareous or siliceous gravel.
6.2
5.3
4.2
2.8
4. Solid concreteh,
							 i
4-1.1
Siliceous aggregate concrete.
7.0
6.2
5.0
3.5
Carbonate aggregate concrete.
6.6
5.7
4.6
3.2
Sand-lightweight concrete.
5.4
4.6
3.8
2.7
Lightweight concrete.
5.1
4.4
3.6
2.5
5. Glazed or unglazed facing tile,
							 nonload-bearing
5-1.1
One 2" unit cored 15 percent maximum and one 4" unit
							 cored 25 percent maximum with ¾" mortar-filled collar joint. Unit
							 positions reversed in alternate courses.
-
63/8
-
-
5-1.2
One 2" unit cored 15 percent maximum and one 4" unit
							 cored 40 percent maximum with ¾" mortar-filled collar joint. Unit
							 positions side with ¾" gypsum plaster. Two wythes tied together every
							 fourth course with No. 22 gage corrugated metal ties.
-
6 ¾
-
-
5-1.3
One unit with three cells in wall thickness, cored 29
							 percent maximum.
-
-
6
-
5-1.4
One 2" unit cored 22 percent maximum and one 4" unit
							 cored 41 percent maximum with ¼ " mortar-filled collar joint. Two wythes
							 tied together every third course with 0.030" (No. 22 galvanized sheet steel
							 gage) corrugated metal ties.
-
-
6
-
5-1.5
One 4" unit cored 25 percent maximum with ¾"
							 gypsum plaster on one side.
-
-
4¾
-
5-1.6
One 4" unit with two cells in wall thickness, cored 22
							 percent maximum.
-
-
-
4
5-1.7
One 4" unit cored 30 percent maximum with ¾"
							 vermiculite gypsum plaster on one side.
-
-
4½
-
5-1.8
One 4" unit cored 39 percent maximum with ¾"
							 gypsum plaster on one side.
-
-
-
4½
6. Solid gypsum plaster
6-1.1
¾" by 0.055" (No. 16 carbon sheet steel gage)
							 vertical cold-rolled channels, 16" on center with 2.6-pound flat metal lath
							 applied to one face and tied with 0.049" (No. 18 B.W. Gage) wire at 6" spacing.
							 Gypsum plaster each side mixed 1:2 by weight, gypsum to sand aggregate.
-
-
-
2d
6-1.2
¾" by 0.05" (No. 16 carbon sheet steel gage)
							 cold-rolled channels 16" on center with metal lath applied to one face and tied
							 with 0.049" (No. 18 B.W. gage) wire at 6" spacing. Perlite or vermiculite
							 gypsum plaster each side. For three-coat work, the plaster mix for the second
							 coat shall not exceed 100 pounds of gypsum to 2½ cubic feet of aggregate
							 for the 1-hour system.
-
-
21/2d
2d
6-1.3
¾" by 0.055" (No. 16 carbon sheet steel gage)
							 vertical cold-rolled channels, 16" on center
							 with3/8" gypsum lath applied
							 to one face and attached with sheet metal clips. Gypsum plaster each side mixed
							 1:2 by weight, gypsum to sand aggregate.
-
-
-
2d
6-2.1
Studless with½" full-length plain gypsum lath
							 and gypsum plaster each side. Plaster mixed 1:1 for scratch coat and 1:2 for
							 brown coat, by weight, gypsum to sand aggregate.
-
-
-
2d
6-2.2
Studless with½" full-length plain gypsum lath
							 and perlite or vermiculite gypsum plaster each side.
-
-
21/2d
2d
6-2.3
Studless partition
							 with3/8" rib metal lath
							 installed vertically adjacent edges tied 6" on center with No. 18 gage wire
							 ties, gypsum plaster each side mixed 1:2 by weight, gypsum to sand
							 aggregate.
-
-
-
2d
7. Solid perlite and Portland cement
7-1.1
Perlite mixed in the ratio of 3 cubic feet to 100
							 pounds of Portland cement and machine applied to stud side of 1½" mesh
							 by 0.058-inch (No. 17 B.W. gage) paper-backed woven wire fabric lath wire-tied
							 to 4"-deep steel trussed wirej studs 16" on center.
							 Wire ties of 0.049" (No. 18 B.W. gage) galvanized steel wire 6" on center
							 vertically.
-
-
31/8d
-
8. Solid neat wood fibered gypsum plaster
8-1.1
¾ " by 0.055-inch (No. 16 carbon sheet steel
							 gage) cold-rolled channels, 12" on center with 2.5-pound flat metal lath
							 applied to one face and tied with 0.049" (No. 18 B.W. gage) wire at 6" spacing.
							 Neat gypsum plaster applied each side.
-
-
2d
-
9. Solid wallboard partition
9-1.1
One full-length layer ½ " Type X gypsum
							 wallboarde laminated to each side of 1" full-length
							 V-edge gypsum coreboard with approved laminating compound. Vertical joints of
							 face layer and coreboard staggered at least 3".
-
2d
-
10. Hollow (studless) gypsum wallboard
							 partition
10-1.1
One full-length layer of
							 5/8 " Type X gypsum
							 wallboarde attached to both sides of wood or metal
							 top and bottom runners laminated to each side of 1" × 6" full-length
							 gypsum coreboard ribs spaced 2" on center with approved laminating compound.
							 Ribs centered at vertical joints of face plies and joints staggered 24" in
							 opposing faces. Ribs may be recessed 6" from the top and bottom.
-
-
-
21/4d
10-1.2
1" regular gypsum V-edge full-length backing board
							 attached to both sides of wood or metal top and bottom runners with nails or
							 15/8 " drywall screws at 24"
							 on center. Minimum width of rumors 1
							 5/8". Face layer of ½"
							 regular full-length gypsum wallboard laminated to outer faces of backing board
							 with approved laminating compound.
-
-
45/8d
-
11. Noncombustible studs-interior partition
							 with plaster each side
11-1.1
3¼" × 0.044" (No. 18 carbon sheet steel
							 gage) steel studs spaced 24" on center.
							 5/8" gypsum plaster on metal
							 lath each side mixed 1:2 by weight, gypsum to sand aggregate.
-
-
-
4¾d
11-1.2
33/8" × 0.055" (No. 16
							 carbon sheet steel gage) approved nailable k studs
							 spaced 24" on center. 5/8"
							 neat gypsum wood-fibered plaster each side
							 over3/8" rib metal lath
							 nailed to studs with 6d common nails, 8" on center. Nails driven 1¼" and
							 bent over.
-
-
55/8
-
11-1.3
4" × 0.044" (No. 18 carbon sheet steel gage)
							 channel-shaped steel studs at 16" on center. On each side approved resilient
							 clips pressed onto stud flange at 16" vertical spacing, ¼" pencil rods
							 snapped into or wire tied onto outer loop of clips, metal lath wire-tied to
							 pencil rods at 6" intervals, 1" perlite gypsum plaster, each side.
-
75/8d
-
-
11-1.4
2½" × 0.044" (No. 18 carbon sheet steel
							 gage) steel studs spaced 16" on center. Wood fibered gypsum plaster mixed 1:1
							 by weight gypsum to sand aggregate applied on ¾-pound metal lath wire
							 tied to studs, each side. ¾" plaster applied over each face, including
							 finish coat.
-
-
4¼d
-
12. Wood studs interior partition with
							 plaster each side
12-1.1l, m
2" × 4" wood studs 16" on center
							 with5/8" gypsum plaster on
							 metal lath. Lath attached by 4d common nails bent over or No. 14 gage by
							 1¼" by ¾" crown width staples spaced 6" on center. Plaster mixed
							 1:1½ for scratch coat and 1:3 for brown coat, by weight, gypsum to sand
							 aggregate.
-
-
-
51/8
12-1.2l
2" × 4" wood studs 16" on center with metal lath
							 and 7/8 " neat wood-fibered
							 gypsum plaster each side. Lath attached by 6d common nails, 7" on center. Nails
							 driven 1¼" and bent over.
-
-
5½d
-
12-1.3l
2" × 4" wood studs 16" on center with
							 3/8" perforated or plain
							 gypsum lath and ½" gypsum plaster each side. Lath nailed with 11/8" by
							 No. 13 gage by 19/64" head
							 plasterboard blued nails, 4" on center. Plaster mixed 1:2 by weight, gypsum to
							 sand aggregate.
-
-
-
5¼
12-1.4l
2" × 4" wood studs 16" on center with
							 3/8" Type X gypsum lath and
							 ½" gypsum plaster each side. Lath nailed with
							 11/8" by No. 13 gage by
							 19/64" head plasterboard
							 blued nails, 5" on center. Plaster mixed 1:2 by weight, gypsum to sand
							 aggregate.
-
-
-
5¼
13. Noncombustible studs-interior partition
							 with gypsum wallboard each side
13-1.1
0.018" (No. 25 carbon sheet steel gage) channel-shaped
							 studs 24" on center with one full-length layer of
							 5/8" Type X gypsum wallboard
							 e applied vertically attached with 1" long No. 6 drywall screws to each stud.
							 Screws are 8" on center around the perimeter and 12" on center on the
							 intermediate stud. The wallboard may be applied horizontally when attached to
							 35/8" studs and the
							 horizontal joints are staggered with those on the opposite side. Screws for the
							 horizontal application shall be 8" on center at vertical edges and 12" on
							 center at intermediate studs.
-
-
-
27/8d
13-1.2
0.018" (No. 25 carbon sheet steel gage) channel-shaped
							 studs 25" on center with two full-length layers of ½" Type X gypsum
							 wallboard e applied vertically each side. First
							 layer attached with 1"-long, No. 6 drywall screws, 8" on center around the
							 perimeter and 12" on center on the intermediate stud. Second layer applied with
							 vertical joints offset one stud space from first layer using
							 15/8" long, No. 6 drywall
							 screws spaced 9" on center along vertical joints, 12" on center at intermediate
							 studs and 24" on center along top and bottom runners.
-
-
35/8d
-
13-1.3
0.055" (No. 16 carbon sheet steel gage) approved
							 nailable metal studse 24" on center with full-length
							 5/8" Type X gypsum
							 wallboarde applied vertically and nailed 7" on
							 center with 6d cement-coated common nails. Approved metal fastener grips used
							 with nails at vertical butt joints along studs.
-
-
-
47/8
14. Wood studs-interior partition with
							 gypsum wallboard each side
14-1.1h, m
2" × 4" wood studs 16" on center with two layers
							 of 3/8 " regular gypsum
							 wallboarde each side, 4d cooler
							 n or wallboard n nails at
							 8" on center first layer, 5d coolern or wallboard
							 n nails at 8" on center second layer with laminating
							 compound between layers, joints staggered. First layer applied full length
							 vertically, second layer applied horizontally or vertically.
-
-
-
5
14-1.2l, m
2" × 4" wood studs 16" on center with two layers
							 ½ " regular gypsum wallboard e applied
							 vertically or horizontally each sidek, joints
							 staggered. Nail base layer with 5d cooler n or
							 wallboardn nails at 8" on center face layer with 8d
							 cooler n or wallboardn
							 nails at 8" on center.
-
-
-
5½
14-1.3l, m
2" × 4" wood studs 24" on center with
							 5/8 " Type X gypsum
							 wallboarde applied vertically or horizontally nailed
							 with 6d cooler n or
							 wallboardn nails at 7" on center with end joints on
							 nailing members. Stagger joints each side.
-
-
-
4¾
14-1.4 l
2" × 4" fire-retardant-treated wood studs spaced
							 24" on center with one layer of
							 5/8 " Type X gypsum
							 wallboarde applied with face paper grain (long
							 dimension) parallel to studs. allboard attached with 6d
							 coolern or wallboardn
							 nails at 7" on center.
-
-
-
4¾d
14-1.5l, m
2" × 4" wood studs 16" on center with two
							 layers5/8" Type X gypsum
							 wallboarde each side. Base layers applied vertically
							 and nailed with 6d coolern or
							 wallboardn nails at 9" on center. Face layer applied
							 vertically or horizontally and nailed with 8d
							 coolern or wallboard n
							 nails at 7" on center. For nail-adhesive application, base layers are nailed 6"
							 on center. Face layers applied with coating of approved wallboard adhesive and
							 nailed 12" on center.
-
-
6
-
14-1.6l
2" × 3" fire-retardant-treated wood studs spaced
							 24" on center with one layer of 5/8
							 " Type X gypsum wallboarde applied with
							 face paper grain (long dimension) at right angles to studs. Wallboard attached
							 with 6d cement-coated box nails spaced 7" on center.
-
-
-
35/8d
15. Exterior or interior walls
							 (continued)
15-1.1l, m
Exterior surface with ¾" drop siding over
							 ½" gypsum sheathing on 2" × 4" wood studs at 16" on center,
							 interior surface treatment as required for 1-hour-rated exterior or interior 2"
							 × 4" wood stud partitions. Gypsum sheathing nailed with 1¾" by No.
							 11 gage by 7/16" head
							 galvanized nails at 8" on center. Siding nailed with 7d galvanized smooth box
							 nails.
-
-
-
Varies
15-1.2l, m
2" × 4" wood studs 16" on center with metal lath
							 and ¾ " cement plaster on each side. Lath attached with 6d common nails
							 7" on center driven to 1" minimum penetration and bent over. Plaster mix 1:4
							 for scratch coat and 1:5 for brown coat, by volume, cement to sand.
-
-
-
53/8
15-1.3l, m
2" × 4" wood studs 16" on center with
							 7/8" cement plaster (measured
							 from the face of studs) on the exterior surface with interior surface treatment
							 as required for interior wood stud partitions in this table. Plaster mix 1:4
							 for scratch coat and 1:5 for brown coat, by volume, cement to sand.
-
-
-
Varies
15-1.4
35/8
							 " No. 16 gage noncombustible studs 16" on center with
							 7/8 " cement plaster
							 (measured from the face of the studs) on the exterior surface with interior
							 surface treatment as required for interior, nonbearing, noncombustible stud
							 partitions in this table. Plaster mix 1:4 for scratch coat and 1:5 for brown
							 coat, by volume, cement to sand.
-
-
-
Variesd
15. Exterior or interior walls
							 (continued)
15-1.5m
2¼" × 3¾" clay face brick with
							 cored holes over ½" gypsum sheathing on exterior surface of 2" ×
							 4" wood studs at 16" on center and two layers
							 5/8" Type X gypsum wallboard
							 eon interior surface. Sheathing placed horizontally
							 or vertically with vertical joints over studs nailed 6" on center with
							 1¾" × No. 11 gage by
							 7/16" head galvanized nails.
							 Inner layer of wallboard placed horizontally or vertically and nailed 8" on
							 center with 6d coolern or
							 wallboardn nails. Outer layer of wallboard placed
							 horizontally or vertically and nailed 8" on center with 8d
							 coolern or wallboardn
							 nails. All joints staggered with vertical joints over studs. Outer layer joints
							 taped and finished with compound. Nail heads covered with joint compound. 0.035
							 inch (No. 20 galvanized sheet gage) corrugated galvanized steel wall
							 ties¾" by 65/8"
							 attached to each stud with two 8d cooler n or
							 wallboard n nails every sixth course of bricks.
-
-
10
-
15-1.6l, m
2" × 6" fire-retardant-treated wood studs 16" on
							 center. Interior face has two layers of
							 5/8" Type X gypsum with the
							 base layer placed vertically and attached with 6d box nails 12" on center. The
							 face layer is placed horizontally and attached with 8d box nails 8" on center
							 at joints and 12" on center elsewhere. The exterior face has a base layer of
							 5/8" Type X gypsum sheathing
							 placed vertically with 6d box nails 8" on center at joints and 12" on center
							 elsewhere. An approved building paper is next applied, followed by self-furred
							 exterior lath attached with 2½", No. 12 gage galvanized roofing nails
							 with a 3/8" diameter head and
							 spaced 6" on center along each stud. Cement plaster consisting of a ½"
							 brown coat is then applied. The scratch coat is mixed in the proportion of 1:3
							 by weight, cement to sand with 10 pounds of hydrated lime and 3 pounds of
							 approved additives or admixtures per sack of cement. The brown coat is mixed in
							 the proportion of 1:4 by weight, cement to sand with the same amounts of
							 hydrated lime and approved additives or admixtures used in the scratch
							 coat.
-
-
8¼
-
15-1.7l, m
2" × 6" wood studs 16" on center. The exterior
							 face has a layer of 5 /8"
							 Type X gypsum sheathing placed vertically with 6d box nails 8" on center at
							 joints and 12" on center elsewhere. An approved building paper is next applied,
							 followed by 1" by No. 18 gage self-furred exterior lath attached with 8d by
							 2½" long galvanized roofing nails spaced 6" on center along each stud.
							 Cement plaster consisting of a ½" scratch coat, a bonding agent and a
							 ½" brown coat and a finish coat is then applied. The scratch coat is
							 mixed in the proportion of 1:3 by weight, cement to sand with 10 pounds of
							 hydrated lime and 3 pounds of approved additives or admixtures per sack of
							 cement. The brown coat is mixed in the proportion of 1:4 by weight, cement to
							 sand with the same amounts of hydrated lime and approved additives or
							 admixtures used in the scratch coat. The interior is covered with
							 3/8" gypsum lath with 1" hexagonal mesh of
							 0.035 inch (No. 20 B.W. gage) woven wire lath furred out
							 5/16" and 1" perlite or
							 vermiculite gypsum plaster. Lath nailed with
							 11/8" by No. 13 gage by
							 19/64" head plasterboard glued nails spaced 5" on center. Mesh attached by
							 1¾" by No. 12 gage by
							 3/8" head nails with
							 3/8" furrings, spaced 8" on
							 center. The plaster mix shall not exceed 100 pounds of gypsum to 2½
							 cubic feet of aggregate.
-
-
83/8
-
15. Exterior or interior walls
							 (continued)
15-1.8l, m
2" × 6" wood studs 16" on center. The exterior
							 face has a layer of 5/8" Type
							 X gypsum sheathing placed vertically with 6d box nails 8" on center at joints
							 and 12" on center elsewhere. An approved building paper is next applied,
							 followed by 1½" by No. 17 gage self-furred exterior lath attached with
							 8d by 2½" long galvanized roofing nails spaced 6" on center along each
							 stud. Cement plaster consisting of a ½ " scratch coat, and a ½"
							 brown coat is then applied. The plaster may be placed by machine. The scratch
							 coat is mixed in the proportion of 1:4 by weight, plastic cement to sand. The
							 brown coat is mixed in the proportion of 1:5 by weight, plastic cement to sand.
							 The interior is covered with
							 3/8" gypsum lath with 1"
							 hexagonal mesh of No. 20 gage woven wire lath furred out
							 5/16" and 1" perlite or
							 vermiculite gypsum plaster. Lath nailed with
							 11/8" by No. 13 gage by
							 19/64" head plasterboard
							 glued nails spaced 5" on center. Mesh attached by 1¾ " by No. 12 gage by
							 3/8" head nails with
							 3/8" furrings, spaced 8" on
							 center. The plaster mix shall not exceed 100 pounds of gypsum to 2½
							 cubic feet of aggregate.
-
-
83/8
-
15-1.9
4" No. 18 gage, nonload-bearing metal studs, 16" on
							 center, with 1" Portland cement lime plaster [measured from the back side of
							 the ¾ -pound expanded metal lath] on the exterior surface. Interior
							 surface to be covered with 1" of gypsum plaster on ¾ -pound expanded
							 metal lath proportioned by weight-1:2 for scratch coat, 1:3 for brown, gypsum
							 to sand. Lath on one side of the partition fastened to ¼" diameter
							 pencil rods supported by No. 20 gage metal clips, located 16" on center
							 vertically, on each stud. 3" thick mineral fiber insulating batts friction
							 fitted between the studs.
-
-
6½d
-
15-1.10
Steel studs 0.060" thick, 4" deep or 6" at 16" or 24"
							 centers, with ½" Glass Fiber Reinforced Concrete (GFRC) on the exterior
							 surface. GFRC is attached with flex anchors at 24" on center, with 5" leg
							 welded to studs with two ½ "-long flare-bevel welds, and 4" foot
							 attached to the GFRC skin with
							 5/8" thick GFRC bonding pads
							 that extend 2½" beyond the flex anchor foot on both sides. Interior
							 surface to have two layers of ½" Type X gypsum wallboard. e The first
							 layer of wallboard to be attached with 1"-long Type S buglehead screws spaced
							 24" on center and the second layer is attached with
							 15/8 "-long Type S screws
							 spaced at 12" on center. Cavity is to be filled with 5" of 4 pcf (nominal)
							 mineral fiber batts. GFRC has 1½ " returns packed with mineral fiber and
							 caulked on the exterior.
-
-
6½
-
15-1.11
Steel studs 0.060" thick, 4" deep or 6" at 16" or 24"
							 centers, respectively, with ½" Glass Fiber Reinforced Concrete (GFRC) on
							 the exterior surface. GFRC is attached with flex anchors at 24" on center, with
							 5" leg welded to studs with two ½"-long flare-bevel welds, and 4" foot
							 attached to the GFRC skin with
							 5/8" -thick GFRC bonding pads
							 that extend 2½" beyond the flex anchor foot on both sides. Interior
							 surface to have one layer of
							 5/8" Type X gypsum
							 wallboarde , attached with 1¼"-long Type S
							 buglehead screws spaced 12" on center. Cavity is to be filled with 5" of 4 pcf
							 (nominal) mineral fiber batts. GFRC has 1½" returns packed with mineral
							 fiber and caulked on the exterior.
-
-
-
61/8
15-1.12q
2" × 6" wood studs at 16" with double top
							 plates, single bottom plate; interior and exterior sides covered with
							 5/8 " Type X gypsum
							 wallboard, 4' wide, applied horizontally or vertically with vertical joints
							 over studs, and fastened with 2¼" Type S drywall screws, spaced 12" on
							 center. Cavity to be filled with 5½" mineral wool insulation.
-
-
-
6¾
15. Exterior or interior walls
							 (continued)
15-1.13q
2" × 6" wood studs at 16" with double top
							 plates, single bottom plate; interior and exterior sides covered with
							 5/8" Type X gypsum wallboard,
							 4' wide, applied vertically with all joints over framing or blocking and
							 fastened with 2¼" Type S drywall screws, spaced 12" on center. R-19
							 mineral fiber insulation installed in stud cavity.
-
-
-
6¾
15-1.14q
2" × 6" wood studs at 16" with double top
							 plates, single bottom plate; interior and exterior sides covered with
							 5/8" Type X gypsum wallboard,
							 4' wide, applied horizontally or vertically with vertical joints over studs,
							 and fastened with 2¼" Type S drywall screws, spaced 7" on center.
-
-
-
6¾
15-1.15q
2" × 4" wood studs at 16" with double top
							 plates, single bottom plate; interior and exterior sides covered with
							 5/8" Type X gypsum wallboard
							 and sheathing, respectively, 4' wide, applied horizontally or vertically with
							 vertical joints over studs, and fastened with 2¼" Type S drywall screws,
							 spaced 12" on center. Cavity to be filled with 3½" mineral wool
							 insulation.
-
-
-
4¾
15-1.16q
2" x 6" wood studs at 24" centers with double top
							 plates, single bottom plate; interior and exterior side covered with two layers
							 of 5 /8" Type X gypsum
							 wallboard, 4' wide, applied horizontally with vertical joints over studs. Base
							 layer fastened with 2¼" Type S drywall screws, spaced 24" on center and
							 face layer fastened with Type S drywall screws, spaced 8" on center, wallboard
							 joints covered with paper tape and joint compound, fastener heads covered with
							 joint compound. Cavity to be filled with 5½" mineral wool
							 insulation.
-
-
8
-
15-2.1d
35/8" No. 16 gage steel studs
							 at 24" on center or 2" × 4" wood studs at 24" on center. Metal lath
							 attached to the exterior side of studs with minimum 1" long No. 6 drywall
							 screws at 6" on center and covered with minimum ¾" thick Portland cement
							 plaster. Thin veneer brick units of clay or shale complying with ASTM C 1088,
							 Grade TBS or better, installed in running bond in accordance with Section
							 1405.10 . Combined total thickness of the Portland cement plaster, mortar and
							 thin veneer brick units shall be not less than 1¾". Interior side
							 covered with one layer of
							 5/8" thick Type X gypsum
							 wallboard attached to studs with 1" long No. 6 drywall screws at 12" on
							 center.
-
-
-
6
15-2.2d
35/8" No. 16 gage steel studs
							 at 24" on center or 2" × 4" wood studs at 24" on center. Metal lath
							 attached to the exterior side of studs with minimum 1" long No. 6 drywall
							 screws at 6" on center and covered with minimum ¾" thick Portland cement
							 plaster. Thin veneer brick units of clay or shale complying with ASTM C 1088,
							 Grade TBS or better, installed in running bond in accordance with Section
							 1405.10 . Combined total thickness of the Portland cement plaster, mortar and
							 thin veneer brick units shall be not less than 2". Interior side covered with
							 two layers of 5/8" thick Type
							 X gypsum wallboard. Bottom layer attached to studs with 1" long No. 6 drywall
							 screws at 24" on center. Top layer attached to studs with
							 15/8" long No. 6 drywall
							 screws at 12" on center.
-
-
67/8
-
15-2.3d
35/8
							 " No. 16 gage steel studs at 16" on center or 2"× 4" wood studs at 16" on
							 center. Where metal lath is used, attach to the exterior side of studs with
							 minimum 1" long No. 6 drywall screws at 6" on center. Brick units of clay or
							 shale not less than 25/8"
							 thick complying with ASTM C 216 installed in accordance with Section 1405.6
							 with a minimum 1" air space. Interior side covered with one layer of
							 5/8" thick Type X gypsum
							 wallboard attached to studs with 1" long No. 6 drywall screws at 12" on
							 center.
-
-
-
77/8
15. Exterior or interior walls
15-2.4d
35/8" No. 16 gage steel studs
							 at 16" on center or 2" × 4" wood studs at 16" on center. Where metal lath
							 is used, attach to the exterior side of studs with minimum 1" long No. 6
							 drywall screws at 6" on center. Brick units of clay or shale not less than
							 25 /8" thick complying with
							 ASTM C 216 installed in accordance with Section 1405.6 with a minimum 1" air
							 space. Interior side covered with two layers of
							 5/8 " thick Type X gypsum
							 wallboard. Bottom layer attached to studs with 1" long No. 6 drywall screws at
							 24" on center. Top layer attached to studs with
							 15/8" long No. 6 drywall
							 screws at 12" on center.
-
-
8 ½
-
16. Exterior walls rated for fire
							 resistance from the inside only in accordance with Section 705.5 .
16-1.1q
2" × 4" wood studs at 16" centers with double
							 top plates, single bottom plate; interior side covered with 5/8" Type X gypsum
							 wallboard, 4" wide, applied horizontally unblocked, and fastened with
							 2¼" Type S drywall screws, spaced 12" on center, wallboard joints
							 covered with paper tape and joint compound, fastener heads covered with joint
							 compound. Exterior covered with
							 3/8" wood structural panels,
							 applied vertically, horizontal joints blocked and fastened with 6d common nails
							 (bright) - 12" on center in the field, and 6" on center panel edges. Cavity to
							 be filled with 3" mineral wool insulation. Rating established for exposure from
							 interior side only.
-
-
-
4½
16-1.2q
2" × 6" wood studs at 16" centers with double
							 top plates, single bottom plate; interior side covered with
							 5/8" Type X gypsum wallboard,
							 4" wide, applied horizontally or vertically with vertical joints over studs and
							 fastened with 2¼" Type S drywall screws, spaced 12" on center, wallboard
							 joints covered with paper tape and joint compound, fastener heads covered with
							 joint compound, exterior side covered with
							 7/16" wood structural panels
							 fastened with 6d common nails (bright) spaced 12" on center in the field and 6"
							 on center along the panel edges. Cavity to be filled with 5½" mineral
							 wool insulation. Rating established from the gypsum-covered side only.
-
-
-
69/16
16-1.3q
2" × 6" wood studs at 16" centers with double
							 top plates, single bottom plates; interior side covered with
							 5/8" Type X gypsum wallboard,
							 4" wide, applied vertically with all joints over framing or blocking and
							 fastened with 2¼" Type S drywall screws spaced 7" on center. Joints to
							 be covered with tape and joint compound. Exterior covered with
							 3/8" wood structural panels,
							 applied vertically with edges over framing or blocking and fastened with 6d
							 common nails (bright) at 12" on center in the field and 6" on center on panel
							 edges. R-19 mineral fiber insulation installed in stud cavity. Rating
							 established from the gypsum-covered side only.
-
-
-
6½
For SI: 1 inch = 25.4 mm, 1 square inch = 645.2
							 mm2, 1 cubic foot = 0.0283
							 m3 foot = 304.8 mm.
a. Staples with equivalent holding power and
							 penetration shall be permitted to be used as alternate fasteners to nails for
							 attachment to wood framing.
b. Thickness shown for brick and clay tile is nominal
							 thicknesses unless plastered, in which case thicknesses are net. Thickness
							 shown for concrete masonry and clay masonry is equivalent thickness defined in
							 Section 721. 2.3.1 for concrete masonry and Section 722.4.1.1 for clay masonry.
							 Where all cells are solid grouted or filled with silicone-treated perlite
							 loose-fill insulation; vermiculite loose-fill insulation; or expanded clay,
							 shale or slate lightweight aggregate, the equivalent thickness shall be the
							 thickness of the block or brick using specified dimensions as defined in
							 Chapter 21 . Equivalent thickness may also include the thickness of applied
							 plaster and lath or gypsum wallboard, where specified.
c. For units in which the net cross-sectional area of
							 cored brick in any plane parallel to the surface containing the cores is at
							 least 75 percent of the gross cross-sectional area measured in the same
							 plane.
d. Shall be used for nonbearing purposes only.
e. For all of the construction with gypsum wallboard
							 described in this table, gypsum base for veneer plaster of the same size,
							 thickness and core type shall be permitted to be substituted for gypsum
							 wallboard, provided attachment is identical to that specified for the
							 wallboard, and the joints on the face layer are reinforced and the entire
							 surface is covered with a minimum of
							 1/16-inch gypsum veneer
							 plaster.
f. The fire-resistance time period for concrete masonry
							 units meeting the equivalent thicknesses required for a 2-hour fire-resistance
							 rating in Item 3, and having a thickness of not less than
							 75/8 inches is 4 hours when
							 cores which are not grouted are filled with silicone-treated perlite loose-fill
							 insulation; vermiculite loose-fill insulation; or expanded clay, shale or slate
							 lightweight aggregate, sand or slag having a maximum particle size of
							 3/8inch.
g. The fire-resistance rating of concrete masonry units
							 composed of a combination of aggregate types or where plaster is applied
							 directly to the concrete masonry shall be determined in accordance with ACI
							 216.1/TMS 0216. Lightweight aggregates shall have a maximum combined density of
							 65 pounds per cubic foot.
h. See also Note b. The equivalent thickness shall be
							 permitted to include the thickness of cement plaster or 1.5 times the thickness
							 of gypsum plaster applied in accordance with the requirements of Chapter
							 25.
i. Concrete walls shall be reinforced with horizontal
							 and vertical temperature reinforcement as required by Chapter 19.
j. Studs are welded truss wire studs with 0.18 inch
							 (No. 7 B.W. gage) flange wire and 0.18 inch (No. 7 B.W. gage) truss wires.
k. Nailable metal studs consist of two channel studs
							 spot welded back to back with a crimped web forming a nailing groove.
l. Wood structural panels shall be permitted to be
							 installed between the fire protection and the wood studs on either the interior
							 or exterior side of the wood frame assemblies in this table, provided the
							 length of the fasteners used to attach the fire protection is increased by an
							 amount at least equal to the thickness of the wood structural panel.
m. The design stress of studs shall be reduced to 78
							 percent of allowable
F
'c with the
							 maximum not greater than 78 percent of the calculated stress with studs having
							 a slenderness ratio
l
e
/d
of 33.
n. For properties of cooler or wallboard nails, see
							 ASTM C 514, ASTM C 547 or ASTM F 1667.
o. Generic fire-resistance ratings (those not
							 designated as PROPRIETARY* in the listing) in the GA 600 shall be accepted as
							 if herein listed.
p. NCMA TEK 5-8A shall be permitted for the design of
							 fire walls.
q. The design stress of studs shall be equal to a
							 maximum of 100 percent of the allowable
F'c
calculated in accordance with
							 Section 2306 .
TABLE 720.1(3) MINIMUM PROTECTION FOR FLOOR AND ROOF
				  SYSTEMSa, q
FLOOR OR ROOF CONSTRUCTION
ITEM NUMBER
CEILING CONSTRUCTION
THICKNESS OF FLOOR OR ROOF SLAB
							 (inches)
MINIMUM THICKNESS OF CEILING
							 (inches)
4 hours
3 hours
2 hours
1 hour
4 hours
3 hours
2 hours
1 hour
1. Siliceous aggregate concrete
1-1.1
Slab (no ceiling required). Minimum cover
							 over nonprestressed reinforcement shall not be less than ¾"
							 b.
7.0
6.2
5.0
3.5
-
-
-
-
2. Carbonate aggregate concrete
2-1.1
6.6
5.7
4.6
3.2
-
-
-
-
3. Sand-lightweight concrete
3-1.1
5.4
4.6
3.8
2.7
-
-
-
-
4. Lightweight concrete
4-1.1
5.1
4.4
3.6
2.5
-
-
-
-
5. Reinforced concrete
5-1.1
Slab with suspended ceiling of vermiculite gypsum
							 plaster over metal lath attached to ¾" cold-rolled channels spaced 12"
							 on center. Ceiling located 6" minimum below joists.
3
2
-
-
1
¾
-
-
5-2.1
3/8
							 " Type X gypsum wallboard c attached to 0.018 inch (No. 25 carbon
							 sheet steel gage) by 7/8 "
							 deep by 25/8 " hat-shaped
							 galvanized steel channels with 1"-long No. 6 screws. The channels are spaced
							 24" on center, span 35" and are supported along their length at 35" intervals
							 by 0.033" (No. 21 galvanized sheet gage) galvanized steel flat strap hangers
							 having formed edges that engage the lips of the channel. The strap hangers are
							 attached to the side of the concrete joists with
							 5/32" by
							 11/4 " long power-driven
							 fasteners. The wallboard is installed with the long dimension perpendicular to
							 the channels. All end joints occur on channels and supplementary channels are
							 installed parallel to the main channels, 12" each side, at end joint
							 occurrences. The finished ceiling is located approximately 12" below the soffit
							 of the floor slab.
-
-
2½
-
-
-
5/8
-
6. Steel joists constructed with a poured
							 reinforced concrete slab on metal lath forms or steel form units
							 d, e
6-1.1
Gypsum plaster on metal lath attached to the bottom
							 cord with single No. 16 gage or doubled No. 18 gage wire ties spaced 6" on
							 center. Plaster mixed 1:2 for scratch coat, 1:3 for brown coat, by weight,
							 gypsum-to-sand aggregate for 2-hour system. For 3-hour system plaster is
							 neat.
-
-
2½
2¼
-
-
¾
5/8
6-2.1
Vermiculite gypsum plaster on metal lath attached to
							 the bottom chord with single No.16 gage or doubled 0.049-inch (No. 18 B.W.
							 gage) wire ties 6" on center.
-
2
-
-
-
5/8
-
-
6-3.1
Cement plaster over metal lath attached to the bottom
							 chord of joists with single No. 16 gage or doubled 0.049" (No. 18 B.W. gage)
							 wire ties spaced 6" on center. Plaster mixed 1:2 for scratch coat, 1:3 for
							 brown coat for 1-hour system and 1:1 for scratch coat, 1:1 ½ for brown
							 coat for 2-hour system, by weight, cement to sand.
-
-
-
2
-
-
-
5/8f
6-4.1
Ceiling of
							 5/8" Type X wallboard
							 cattached to
							 7/8 " deep by
							 25/8" by 0.021 inch (No. 25
							 carbon sheet steel gage) hat-shaped furring channels 12" on center with 1" long
							 No. 6 wallboard screws at 8" on center. Channels wire tied to bottom chord of
							 joists with doubled 0.049 inch (No. 18 B.W. gage) wire or suspended below
							 joists on wire hangers. g
-
-
2½
-
-
-
5/8
-
6-5.1
Wood-fibered gypsum plaster mixed 1:1 by weight gypsum
							 to sand aggregate applied over metal lath. Lath tied 6" on center to ¾ "
							 channels spaced 13 ½" on center. Channels secured to joists at each
							 intersection with two strands of 0.049 inch (No.18 B.W. gage) galvanized
							 wire.
-
-
2½
-
-
-
¾
-
7. Reinforced concrete slabs and joists
							 with hollow clay tile fillers laid end to end in rows 2½" or more apart;
							 reinforcement placed between rows and concrete cast around and over tile.
7-1.1
5/8
							 " gypsum plaster on bottom of floor or roof construction.
-
-
8h
-
-
-
5/8
-
7-1.2
None
-
-
-
51/2i
-
-
-
-
8. Steel joists constructed with a reinforced concrete
							 slab on top poured on a 1/2" deep steel deck.e
8-1.1
Vermiculite gypsum plaster on metal lath attached to
							 ¾" cold-rolled channels with 0.049" (No. 18 B.W. gage) wire ties spaced
							 6" on center.
21/2j
-
-
-
¾
-
-
-
9. 3" deep cellular steel deck with concrete slab on
							 top. Slab thickness measured to top.
9-1.1
Suspended ceiling of vermiculite gypsum plaster base
							 coat and vermiculite acoustical plaster on metal lath attached at 6" intervals
							 to ¾" cold-rolled channels spaced 12" on center and secured to
							 1½" cold-rolled channels spaced 36" on center with 0.065" (No. 16 B.W.
							 gage) wire. 1½" channels supported by No. 8 gage wire hangers at 36" on
							 center. Beams within envelope and with a 2½" airspace between beam
							 soffit and lath have a 4-hour rating.
2½
-
-
-
11/8k
-
-
-
10. 1½"-deep steel roof deck on steel framing.
							 Insulation board, 30 pcf density, composed of wood fibers with cement binders
							 of thickness shown bonded to deck with unified asphalt adhesive. Covered with a
							 Class A or B roof covering.
10-1.1
Ceiling of gypsum plaster on metal lath. Lath attached
							 to ¾" furring channels with 0.049" (No. 18 B.W. gage) wire ties spaced
							 6" on center. ¾" channel saddle tied to 2" channels with doubled 0.065"
							 (No. 16 B.W. gage) wire ties. 2" channels spaced 36" on center suspended 2"
							 below steel framing and saddle-tied with 0.165" (No. 8 B.W. gage) wire. Plaster
							 mixed 1:2 by weight, gypsum-to-sand aggregate.
-
-
17/8
1
-
-
¾l
¾l
11. 1½"-deep steel roof deck on steel-framing
							 wood fiber insulation board, 17.5 pcf density on top applied over a 15-lb
							 asphalt-saturated felt. Class A or B roof covering.
11-1.1
Ceiling of gypsum plaster on metal lath. Lath attached
							 to ¾" furring channels with 0.049" (No. 18 B.W. gage) wire ties spaced
							 6" on center. ¾" channels saddle tied to 2" channels with doubled 0.065"
							 (No. 16 B.W. gage) wire ties. 2" channels spaced 36" on center suspended 2"
							 below steel framing and saddle tied with 0.165" (No. 8 B.W. gage) wire. Plaster
							 mixed 1:2 for scratch coat and 1:3 for brown coat, by weight, gypsum-to-sand
							 aggregate for 1-hour system. For 2-hour system, plaster mix is 1:2 by weight,
							 gypsum-to-sand aggregate.
-
-
1½
1
-
-
7/8g
¾l
12. 1½" deep steel roof deck on steel-framing
							 insulation of rigid board consisting of expanded perlite and fibers impregnated
							 with integral asphalt waterproofing; density 9 to 12 pcf secured to metal roof
							 deck by ½" wide ribbons of waterproof, cold-process liquid adhesive
							 spaced 6" apart. Steel joist or light steel construction with metal roof deck,
							 insulation, and Class A or B built-up roof
							 covering.e
12-1.1
Gypsum-vermiculite plaster on metal lath wire tied at
							 6" intervals to ¾" furring channels spaced 12" on center and wire tied
							 to 2" runner channels spaced 32" on center. Runners wire tied to bottom chord
							 of steel joists.
-
-
1
-
-
-
7/8
-
13. Double wood floor over wood joists
							 spaced 16" on center.m,n
13-1.1
Gypsum plaster over
							 3/8" Type X gypsum lath. Lath
							 initially applied with not less than four
							 11/8" by No. 13 gage by
							 19/64" head plasterboard
							 blued nails per bearing. Continuous stripping over lath along all joist lines.
							 Stripping consists of 3" wide strips of metal lath attached by 1 ½" by
							 No. 11 gage by ½" head roofing nails spaced 6" on center. Alternate
							 stripping consists of 3" wide 0.049" diameter wire stripping weighing 1 pound
							 per square yard and attached by No.16 gage by 1 ½" by ¾" crown
							 width staples, spaced 4" on center. Where alternate stripping is used, the lath
							 nailing may consist of two nails at each end and one nail at each intermediate
							 bearing. Plaster mixed 1:2 by weight, gypsum-to-sand aggregate.
-
-
-
-
-
-
-
7/8
13-1.2
Cement or gypsum plaster on metal lath. Lath fastened
							 with 1 ½" by No. 11 gage by
							 7/16" head barbed shank
							 roofing nails spaced 5" on center. Plaster mixed 1:2 for scratch coat and 1:3
							 for brown coat, by weight, cement to sand aggregate.
-
-
-
-
-
-
-
5/8
13-1.3
Perlite or vermiculite gypsum plaster on metal lath
							 secured to joists with 1 ½" by No. 11 gage by
							 7/16" head barbed shank
							 roofing nails spaced 5" on center.
-
-
-
-
-
-
-
5/8
13-1.4
½" Type X gypsum
							 wallboardc nailed to joists with 5d
							 coolero or wallboardo
							 nails at 6" on center. End joints of wallboard centered on joists.
-
-
-
-
-
-
-
½
14. Plywood stressed skin panels consisting of
							 5/8" -thick interior C-D
							 (exterior glue) top stressed skin on 2" × 6" nominal (minimum) stringers.
							 Adjacent panel edges joined with 8d common wire nails spaced 6" on center.
							 Stringers spaced 12" maximum on center.
14-1.1
½" -thick wood fiberboard weighing 15 to 18
							 pounds per cubic foot installed with long dimension parallel to stringers or
							 3/8" C-D (exterior glue)
							 plywood glued and/or nailed to stringers. Nailing to be with 5d
							 coolero or wallboardo
							 nails at 12" on center. Second layer of ½" Type X gypsum
							 wallboardc applied with long dimension perpendicular
							 to joists and attached with 8d coolero or
							 wallboardo nails at 6" on center at end joints and
							 8" on center elsewhere. Wallboard joints staggered with respect to fiberboard
							 joints.
-
-
-
-
-
-
-
1
15. Vermiculite concrete slab proportioned 1:4
							 (Portland cement to vermiculite aggregate) on a 1 ½" -deep steel deck
							 supported on individually protected steel framing. Maximum span of deck 6' -
							 10" where deck is less than 0.019 inch (No. 26 carbon steel sheet gage) or
							 greater. Slab reinforced with 4" × 8" 0.109/0.083" (No. 12 /14B.W. gage)
							 welded wire mesh.
15-1.1
None
-
-
-
3j
-
-
-
-
16. Perlite concrete slab proportioned 1:6 (Portland
							 cement to perlite aggregate) on a 1¼" -deep steel deck supported on
							 individually protected steel framing. Slab reinforced with 4" × 8"
							 0.109/0.083" (No. 12/14 B.W.
							 gage) welded wire mesh.
16-1.1
None
-
-
-
31/2j
-
-
-
-
17. Perlite concrete slab proportioned 1:6 (Portland
							 cement to perlite aggregate) on a
							 9/16" -deep steel deck
							 supported by steel joists 4' on center. Class A or B roof covering on top.
17-1.1
Perlite gypsum plaster on metal lath wire tied to
							 ¾" furring channels attached with 0.065" (No. 16 B.W. gage) wire ties to
							 lower chord of joists.
-
2p
2p
-
-
7/8
¾
-
18. Perlite concrete slab proportioned 1:6 (Portland
							 cement to perlite aggregate) on 1¼" -deep steel deck supported on
							 individually protected steel framing. Maximum span of deck 6' -10" where deck
							 is less than 0.019" (No. 26 carbon sheet steel gage) and 8' -0" where deck is
							 0.019" (No. 26 carbon sheet steel gage) or greater. Slab reinforced with 0.042"
							 (No. 19 B.W. gage) hexagonal wire mesh. Class A or B roof covering on top.
18-1.1
None
-
2¼p
2¼p
-
-
-
-
-
19. Floor and beam construction consisting of 3" -deep
							 cellular steel floor unit mounted on steel members with 1:4 (proportion of
							 Portland cement to perlite aggregate) perlite-concrete floor slab on top.
19-1.1
Suspended envelope ceiling of perlite gypsum plaster
							 on metal lath attached to ¾" cold-rolled channels, secured to 1½"
							 cold-rolled channels spaced 42" on center supported by 0.203 inch (No. 6 B.W.
							 gage) wire 36" on center. Beams in envelope with 3" minimum airspace between
							 beam soffit and lath have a 4-hour rating.
2p
-
-
-
1l
-
-
-
20. Perlite concrete proportioned 1:6 (Portland cement
							 to perlite aggregate) poured to
							 1/8" thickness above top of
							 corrugations of 15/16" -deep
							 galvanized steel deck maximum span 8'-0" for 0.024" (No. 24 galvanized sheet
							 gage) or 6' 0" for 0.019" (No. 26 galvanized sheet gage) with deck supported by
							 individually protected steel framing. Approved polystyrene foam plastic
							 insulation board having a flame spread not exceeding 75 (1" to 4" thickness)
							 with vent holes that approximate 3 percent of the board surface area placed on
							 top of perlite slurry. A 2' by 4' insulation board contains six 2 ¾"
							 diameter holes. Board covered with 2¼" minimum perlite concrete slab.
							 Slab reinforced with mesh consisting of 0.042" (No. 19 B.W. gage) galvanized
							 steel wire twisted together to form 2" hexagons with straight 0.065" (No. 16
							 B.W. gage) galvanized steel wire woven into mesh and spaced 3". Alternate slab
							 reinforcement shall be permitted to consist of 4" × 8", 0.109/0.238" (No.
							 12/4 B.W. gage), or 2" × 2", 0.083/0.083" (No. 14/14 B.W. gage) welded
							 wire fabric. Class A or B roof covering on top.
20-1.1
None
-
-
Varies
-
-
-
-
-
21. Wood joists, wood I-joists, floor trusses and flat
							 or pitched roof trusses spaced a maximum 24" o.c. with ½" wood
							 structural panels with exterior glue applied at right angles to top of joist or
							 top chord of trusses with 8d nails. The wood structural panel thickness shall
							 not be less than nominal ½" nor less than required by Chapter 23 .
21-1.1
Base layer
							 5/8" Type X gypsum wallboard
							 applied at right angles to joist or truss 24" o.c. with 1¼" Type S or
							 Type W drywall screws 24" o.c. Face layer
							 5/8" Type X gypsum wallboard
							 or veneer base applied at right angles to joist or truss through base layer
							 with 17/8" Type S or Type W
							 drywall screws 12" o.c. at joints and intermediate joist or truss. Face layer
							 Type G drywall screws placed 2" back on either side of face layer end joints,
							 12" o.c.
-
-
-
Varies
-
-
-
1¼
22. Steel joists, floor trusses and flat or pitched
							 roof trusses spaced a maximum 24" o.c. with ½" wood structural panels
							 with exterior glue applied at right angles to top of joist or top chord of
							 trusses with No. 8 screws. The wood structural panel thickness shall not be
							 less than nominal ½" nor less than required by Chapter 23.
22-1.1
Base layer
							 5/8" Type X gypsum board applied at right
							 angles to steel framing 24" on center with 1" Type S drywall screws spaced 24"
							 on center. Face layer 5/8"
							 Type X gypsum board applied at right angles to steel framing attached through
							 base layer with 15/8" Type S
							 drywall screws 12" on center at end joints and intermediate joints and
							 1½" Type G drywall screws 12 inches on center placed 2" back on either
							 side of face layer end joints. Joints of the face layer are offset 24" from the
							 joints of the base layer.
-
-
-
Varies
-
-
-
1¼
23. Wood I-joist (minimum joist depth 9¼" with
							 a minimum flange depth of
							 15/16" and a minimum flange
							 cross-sectional area of 2.3 square inches) at 24" o.c. spacing with 1 inch by 4
							 inch (nominal) wood furring strip spacer applied parallel to and covering the
							 bottom of the bottom flange of each member, tacked in place. 2" mineral wool
							 insulation, 3.5 pcf (nominal) installed adjacent to the bottom flange of the
							 I-joist and supported by the 1" × 4" furring strip spacer.
23-1.1
½" deep single leg resilient channel 16" on
							 center (channels doubled at wallboard end joints), placed perpendicular to the
							 furring strip and joist and attached to each joist by
							 17/8" Type S drywall screws.
							 5/8" Type C gypsum wallboard
							 applied perpendicular to the channel with end joints staggered at least 4' and
							 fastened with 11/8" Type S
							 drywall screws spaced 7" on center. Wallboard joints to be taped and covered
							 with joint compound.
-
-
-
Varies
-
-
-
5/8
24. Wood I-joist (minimum I-joist depth 9¼"
							 with a minimum flange depth of 1½" and a minimum flange cross-sectional
							 area of 5.25 square inches; minimum web thickness of
							 3/8") @ 24" o.c., 1½ "
							 mineral wool insulation (2.5 pcf-nominal) resting on hat-shaped furring
							 channels.
24-1.1
Minimum 0.026" thick hat-shaped channel 16" o.c.
							 (channels doubled at wallboard end joints), placed perpendicular to the joist
							 and attached to each joist by
							 15/8" Type S drywall
							 screws. 5/8" Type C gypsum
							 wallboard applied perpendicular to the channel with end joints staggered and
							 fastened with 11/8" Type S
							 drywall screws spaced 12" o.c. in the field and 8" o.c. at the wallboard ends.
							 Wallboard joints to be taped and covered with joint compound.
-
-
-
Varies
-
-
-
5/8
25. Wood I-joist (minimum I-joist depth 9¼"
							 with a minimum flange depth of 1½" and a minimum flange cross-sectional
							 area of 5.25 square inches; minimum web thickness of
							 7/16") @ 24" o.c., 1
							 1 /2" mineral wool insulation
							 (2.5 pcf-nominal) resting on resilient channels.
25-1.1
Minimum 0.019" thick resilient channel 16" o.c.
							 (channels doubled at wallboard end joints), placed perpendicular to the joist
							 and attached to each joist by
							 15/8" Type S drywall screws.
							 5/8" Type C gypsum wallboard
							 applied perpendicular to the channel with end joints staggered and fastened
							 with 1" Type S drywall screws spaced 12" o.c. in the field and 8" o.c. at the
							 wallboard ends. Wallboard joints to be taped and covered with joint
							 compound.
-
-
-
Varies
-
-
-
5/8
26. Wood I-joist (minimum I-joist depth 9¼"
							 with a minimum flange thickness of 1½" and a minimum flange
							 cross-sectional area of 2.25 square inches; minimum web thickness of
							 3/8") @ 24" o.c.
26-1.1
Two layers of ½" Type X gypsum wallboard
							 applied with the long dimension perpendicular to the I-joists with end joints
							 staggered. The base layer is fastened with
							 15/8" Type S drywall screws
							 spaced 12" o.c. and the face layer is fastened with 2" Type S drywall screws
							 spaced 12" o.c. in the field and 8" o.c. on the edges. Face layer end joints
							 shall not occur on the same I-joist as base layer end joints and edge joints
							 shall be offset 24" from base layer joints. Face layer to also be attached to
							 base layer with 1½" Type G drywall screws spaced 8" o.c. placed 6" from
							 face layer end joints. Face layer wallboard joints to be taped and covered with
							 joint compound.
-
-
-
Varies
-
-
-
1
27. Wood I-joist (minimum I-joist depth 9½"
							 with a minimum flange depth of
							 15/16" and a minimum flange
							 cross-sectional area of 1.95 square inches; minimum web thickness of
							 3/8") @ 24" o.c.
27-1.1
Minimum 0.019" thick resilient channel 16" o.c.
							 (channels doubled at wallboard end joints), placed perpendicular to the joist
							 and attached to each joist by
							 15/8" Type S drywall screws.
							 Two layers of ½" Type X gypsum wallboard applied with the long dimension
							 perpendicular to the I-joists with end joints staggered. The base layer is
							 fastened with 1¼" Type S drywall screws spaced 12" o.c. and the face
							 layer is fastened with 15/8"
							 Type S drywall screws spaced 12" o.c. Face layer end joints shall not occur on
							 the same I-joist as base layer end joints and edge joints shall be offset 24"
							 from base layer joints. Face layer to also be attached to base layer with
							 1½" Type G drywall screws spaced 8" o.c. placed 6" from face layer end
							 joints. Face layer wallboard joints to be taped and covered with joint
							 compound.
-
-
-
Varies
-
-
-
1
28. Wood I-joist (minimum I-joist depth 9¼" with
							 a minimum flange depth of 1½" and a minimum flange cross-sectional area
							 of 2.25 square inches; minimum web thickness of
							 3/8") @ 24" o.c. Unfaced
							 fiberglass insulation is installed between the I-joists supported on the upper
							 surface of the flange by stay wires spaced 12" o.c.
28-1.1
Base layer of
							 5/8" Type C gypsum wallboard
							 attached directly to I-joists with
							 15/8" Type S drywall screws
							 spaced 12" o.c. with ends staggered. Minimum 0.0179" thick hat-shaped
							 7/8-inch furring channel 16" o.c. (channels doubled
							 at wallboard end joints), placed perpendicular to the joist and attached to
							 each joist by 15/8" Type S
							 drywall screws after the base layer of gypsum wallboard has been applied. The
							 middle and face layers of
							 5/8" Type C gypsum wallboard
							 applied perpendicular to the channel with end joints staggered. The middle
							 layer is fastened with 1" Type S drywall screws spaced 12" o.c. The face layer
							 is applied parallel to the middle layer but with the edge joints offset 24"
							 from those of the middle layer and fastened with
							 15/8" Type S drywall screws
							 8" o.c. The joints shall be taped and covered with joint compound.
-
-
-
Varies
-
-
2 ¾
-
29. Channel-shaped 18 gage steel joists (minimum depth
							 8") spaced a maximum 24" o.c. supporting tongue-and-groove wood structural
							 panels (nominal minimum ¾" thick) applied perpendicular to framing
							 members. Structural panels attached with
							 1-5/8" Type S-12 screws
							 spaced 12" o.c.
29-1.1
Base layer
							 5/8" Type X gypsum board
							 applied perpendicular to bottom of framing members with
							 11/8" Type S-12 screws spaced
							 12" o.c. Second layer 5/8"
							 Type X gypsum board attached perpendicular to framing members with
							 15/8" Type S-12 screws spaced
							 12" o.c. Second layer joints offset 24" from base layer. Third layer
							 5/8" Type X gypsum board
							 attached perpendicular to framing members with
							 23/8" Type S-12 screws spaced
							 12" o.c. Third layer joints offset 12" from second layer joints.
							 Hat-shaped 7/8-inch rigid
							 furring channels applied at right angles to framing members over third layer
							 with two 23/8" Type S-12
							 screws at each framing member. Face layer
							 5/8" Type X gypsum board
							 applied at right angles to furring channels with
							 11/8" Type S screws spaced
							 12" o.c.
-
-
Varies
-
-
-
33/8
-
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound =
							 0.454 kg, 1 cubic foot = 0.0283 m3,
1 pound per square inch = 6.895 kPa, 1 pound per
							 linear foot = 1.4882 kg/m.
a. Staples with equivalent holding power and
							 penetration shall be permitted to be used as alternate fasteners to nails for
							 attachment to wood framing.
b. When the slab is in an unrestrained condition,
							 minimum reinforcement cover shall not be less than
							 15/8inches for 4 hours
							 (siliceous aggregate only); 11/4inches for 4 and 3 hours; 1 inch for 2 hours
							 (siliceous aggregate only); and
							 3/4inch for all other
							 restrained and unrestrained conditions.
c. For all of the construction with gypsum wallboard
							 described in this table, gypsum base for veneer plaster of the same size,
							 thickness and core type shall be permitted to be substituted for gypsum
							 wallboard, provided attachment is identical to that specified for the
							 wallboard, and the joints on the face layer are reinforced and the entire
							 surface is covered with a minimum of
							 1/16-inch gypsum veneer
							 plaster.
d. Slab thickness over steel joists measured at the
							 joists for metal lath form and at the top of the form for steel form
							 units.
e. (a) The maximum allowable stress level for H-Series
							 joists shall not exceed 22,000 psi.
(b) The allowable stress for K-Series joists shall not
							 exceed 26,000 psi, the nominal depth of such joist shall not be less than 10
							 inches and the nominal joist weight shall not be less than 5 pounds per linear
							 foot.
f. Cement plaster with 15 pounds of hydrated lime and 3
							 pounds of approved additives or admixtures per bag of cement.
g. Gypsum wallboard ceilings attached to steel framing
							 shall be permitted to be suspended with 1½-inch cold-formed carrying
							 channels spaced 48 inches on center, which are suspended with No. 8 SWG
							 galvanized wire hangers spaced 48 inches on center. Cross-furring channels are
							 tied to the carrying channels with No. 18 SWG galvanized wire hangers spaced 48
							 inches on center. Cross-furring channels are tied to the carrying channels with
							 No. 18 SWG galvanized wire (double strand) and spaced as required for direct
							 attachment to the framing. This alternative is also applicable to those steel
							 framing assemblies recognized under Note q.
h. Six-inch hollow clay tile with 2-inch concrete slab
							 above.
i. Four-inch hollow clay tile with 1½-inch
							 concrete slab above.
j. Thickness measured to bottom of steel form
							 units.
k. Five-eighths inch of vermiculite gypsum plaster plus
							 ½ inch of approved vermiculite acoustical plastic.
l. Furring channels spaced 12 inches on center.
m. Double wood floor shall be permitted to be either of
							 the following:
(a) Subfloor of 1-inch nominal boarding, a layer of
							 asbestos paper weighing not less than 14 pounds per 100 square feet and a layer
							 of 1-inch nominal tongue-and-groove finished flooring; or
(b) Subfloor of 1-inch nominal tongue-and-groove
							 boarding or 15/32-inch wood
							 structural panels with exterior glue and a layer of 1-inch nominal
							 tongue-and-groove finished flooring or
							 19/32-inch wood structural panel finish
							 flooring or a layer of Type I Grade M-1 particleboard not less
							 than 5/8-inch thick.
n. The ceiling shall be permitted to be omitted over
							 unusable space, and flooring shall be permitted to be omitted where unusable
							 space occurs above.
o. For properties of cooler or wallboard nails, see
							 ASTM C 514, ASTM C 547 or ASTM F 1667.
p. Thickness measured on top of steel deck unit.
q. Generic fire-resistance ratings (those not
							 designated as PROPRIETARY* in the listing) in the GA 600 shall be accepted as
							 if herein listed.
720.1.1
Thickness of protective coverings.
The thickness of fire-resistant
				materials required for protection of structural members shall be not less than
				set forth in Table 720.1(1), except as modified in this section. The figures
				shown shall be the net thickness of the protecting materials and shall not
				include any hollow space in back of the protection.
720.1.2
Unit masonry protection.
Where required, metal ties shall be embedded in bed joints of unit masonry for
				protection of steel columns. Such ties shall be as set forth in Table 720.1(1)
				or be equivalent thereto.
720.1.3
Reinforcement for cast-in-place concrete column protection.
Cast-in-place concrete protection for steel columns shall be reinforced at the
				edges of such members with wire ties of not less than 0.18 inch (4.6 mm) in
				diameter wound spirally around the columns on a pitch of not more than 8 inches
				(203 mm) or by equivalent reinforcement.
720.1.4
Plaster application.
The
				finish coat is not required for plaster protective coatings where they comply
				with the design mix and thickness requirements of Tables 720.1(1), 720.1(2) and
				720.1(3).
720.1.5
Bonded
				prestressed concrete tendons.
For members having a single tendon or more
				than one tendon installed with equal concrete cover measured from the nearest
				surface, the cover shall not be less than that set forth in Table 720.1(1). For
				members having multiple tendons installed with variable concrete cover, the
				average tendon cover shall not be less than that set forth in Table 720.1(1),
				provided:
1. The clearance from each tendon to
				the nearest exposed surface is used to determine the average cover.
2. In no case can the clear cover for
				individual tendons be less than one-half of that set forth in Table 720.1(1). A
				minimum cover of 3/4 inch
				(19.1 mm) for slabs and 1 inch (25 mm) for beams is required for any aggregate
				concrete.
3. For the purpose of
				establishing a
fire-resistance rating
, tendons having a clear
				covering less than that set forth in Table 720.1(1) shall not contribute more
				than 50 percent of the required ultimate moment capacity for members less than
				350 square inches (0.226 m2) in cross-sectional area
				and 65 percent for larger members. For structural design purposes, however,
				tendons having a reduced cover are assumed to be fully effective.