14B-6-602  Construction classification.
The provisions of Section 602 of IBC are adopted by reference with the following modifications:
1.   Replace Table 602 as shown:
TABLE 602
FIRE-RESISTANCE RATING REQUIREMENTS FOR EXTERIOR WALLS BASED ON FIRE SEPARATION DISTANCEa, d, g
 
FIRE SEPARATION DISTANCE = X
(feet)
TYPE OF CONSTRUCTION
OCCUPANCY
GROUP H
e
OCCUPANCY
GROUP F, S
f
OCCUPANCY
GROUP A, B, E,
M, I, R, U h
X < 3 b
VA, VB
Others
NP
3
NP
2
2 h, j
2
3   X < 5
All
3
2
1
5   X < 10
IA
Others
3
2
2
1
1
1
10 X < 30
IA, IB
IIB, VB
Others
2
1
1
1 k
0
1
k
1 c, k
0
1
c, k
X 30
All
0
0
0
 
For SI: 1 foot = 304.8 mm.
a.   Load-bearing exterior walls shall also comply with the fire-resistance rating requirements of Table 601.
b.   See Section 706.1.1 for party walls.
c.   Open parking garages complying with Section 406 shall not be required to have a fire-resistance rating.
d.   The fire-resistance rating of an exterior wall is determined based upon the fire separation distance of the exterior wall and the story in which the wall is located.
e.   For special requirements for Group H occupancies, see the Chicago Fire Prevention Code.
f.   For special requirements for Group S aircraft hangars, see Section 412.3.1.
g.   Where Table 705.8 permits nonbearing exterior walls with unlimited area of unprotected openings, the required fire-resistance rating for the exterior walls is 0 hours.
h.   A single-story detached private garage, carport or storage building not exceeding 600 square feet (56 m2) in building area, not exceeding 12 feet (3658 mm) in building height and with a roof slope of 2:12 or greater shall be permitted in Type VA or Type VB construction when the fire separation distance is 2 feet (610 mm) or greater and the exterior wall shall not be required to have a fire-resistance rating.
i.   [Reserved.]
j.   Any exterior wall with a fire separation distance of less than 3 feet shall have a fire-resistance rating of not less than 2 hours and shall be built of noncombustible materials, materials allowed by Section 603 or fire-retardant treated wood framing complying with Section 2303.2 with a noncombustible exterior wall covering.
k.   The required fire-resistance rating of exterior walls with a fire separation distance of 10 feet or greater shall only be required to be rated for exposure to fire from the inside in accordance with Section 705.5.
2.   Delete the second sentence of Section 602.3.
3.   Revise Section 602.4 and its subsections to read:
602.4 Type IV.
Type IV construction is that type of construction in which the exterior walls are of noncombustible materials and the interior building elements are of solid wood, laminated wood, heavy timber (HT) or structural composite lumber (SCL) without concealed spaces. The minimum dimensions for permitted materials including solid timber, structural glued-laminated timber, structural composite lumber (SCL), and cross-laminated timber and details of Type IV construction shall comply with the provisions of this section and Section 2304.11. Interior walls and partitions and noncombustible floor and roof assemblies with not less than a 1-hour fire-resistance rating or heavy timber complying with Section 2304.11.2.2 shall be permitted.
602.4.1 [Reserved.]
602.4.2 [Reserved.]
602.4.3 Exterior structural members.
Where a fire separation distance of 20 feet (6096 mm) or more is provided, wood columns and arches conforming to heavy timber sizes complying with Section 2304.11 shall be permitted to be used externally.”
(Amend Coun. J. 2-19-20, p. 14473, Art. II, § 21; Amend Coun. J. 10-7-20, p. 21791, Art. II, § 9)