WSR 19-02-038
PERMANENT RULES
BUILDING CODE COUNCIL
[Filed December 26, 2018, 8:08 a.m., effective July 1, 2019]
Effective Date of Rule: July 1, 2019.
Purpose: Table 1604.5: The purpose is to close an unanticipated loophole regarding daycares.
Mass Timber: The purpose is to comply with ESB 5450.
1613.5: The purpose is to address a structural seismic engineering concern for structures between one hundred sixty feet and two hundred forty feet.
IBC/IFC 3101/3801: The purpose is to resolve inconsistent and conflicting code requirements between NFPA 130, the IBC and IFC as they pertain to passenger rail systems.
Citation of Rules Affected by this Order: New 14; and amending 9.
Statutory Authority for Adoption: RCW 19.27.031, 19.27.074.
Adopted under notice filed as WSR 18-21-100 on October 11 [16], 2018.
A final cost-benefit analysis is available by contacting Richard Brown, 1500 Jefferson Street S.E., Olympia, WA 98504, phone 360-407-9277, email richard.brown@des.wa.gov.
Number of Sections Adopted in Order to Comply with Federal Statute: New 0, Amended 0, Repealed 0; Federal Rules or Standards: New 0, Amended 0, Repealed 0; or Recently Enacted State Statutes: New 0, Amended 0, Repealed 0.
Number of Sections Adopted at the Request of a Nongovernmental Entity: New 14, Amended 9, Repealed 0.
Number of Sections Adopted on the Agency's own Initiative: New 0, Amended 0, Repealed 0.
Number of Sections Adopted in Order to Clarify, Streamline, or Reform Agency Procedures: New 0, Amended 0, Repealed 0.
Number of Sections Adopted using Negotiated Rule Making: New 0, Amended 0, Repealed 0; Pilot Rule Making: New 0, Amended 0, Repealed 0; or Other Alternative Rule Making: New 0, Amended 0, Repealed 0.
Date Adopted: December 1, 2018.
Doug Orth
Council Chair
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-0200Chapter 2—Definitions.
SECTION 202—DEFINITIONS.
ADULT FAMILY HOME. A dwelling, licensed by Washington state, in which a person or persons provide personal care, special care, room and board to more than one but not more than six adults who are not related by blood or marriage to the person or persons providing the services.
ASSISTED LIVING FACILITY. A home or other institution, licensed by the state of Washington, providing housing, basic services and assuming general responsibility for the safety and well-being of residents under chapters 18.20 RCW and 388-78A WAC. These facilities may provide care to residents with symptoms consistent with dementia requiring additional security measures.
BOTTLE FILLING STATION. A plumbing fixture connected to the potable water distribution system and sanitary drainage system that is designed and intended for filling personal use drinking water bottles or containers not less than 10 inches (254 mm) in height. Such fixtures can be separate from or integral to a drinking fountain and can incorporate a water filter and a cooling system for chilling the drinking water.
CHILD CARE. The care of children during any period of a 24-hour day.
CHILD CARE, FAMILY HOME. A child care facility, licensed by Washington state, located in the dwelling of the person or persons under whose direct care and supervision the child is placed, for the care of twelve or fewer children, including children who reside at the home.
CLIMATE ZONE. A geographical region that has been assigned climatic criteria as specified in the Washington State Energy Code.
CLUSTER. Clusters are multiple portable school classrooms separated by less than the requirements of the building code for separate buildings.
EFFICIENCY DWELLING UNIT. A dwelling unit containing only one habitable room.
HOSPICE CARE CENTER. A building or portion thereof used on a 24-hour basis for the provision of hospice services to terminally ill inpatients.
MASS TIMBER. Structural elements of Type IV construction primarily of solid, built-up, panelized or engineered wood products that meet minimum cross section dimensions of Type IV construction.
NIGHTCLUB. An A-2 Occupancy use under the 2006 International Building Code in which the aggregate area of concentrated use of unfixed chairs and standing space that is specifically designated and primarily used for dancing or viewing performers exceeds three hundred fifty square feet, excluding adjacent lobby areas. "Nightclub" does not include theaters with fixed seating, banquet halls, or lodge halls.
NONCOMBUSTIBLE PROTECTION (See MASS TIMBER). Noncombustible material, in accordance with Section 703.5, designed to increase the fire-resistance rating and delay the combustion of mass timber.
PORTABLE SCHOOL CLASSROOM. A prefabricated structure consisting of one or more rooms with direct exterior egress from the classroom(s). The structure is transportable in one or more sections and is designed to be used as an educational space with or without a permanent foundation. The structure shall be capable of being demounted and relocated to other locations as needs arise.
SMALL BUSINESS. Any business entity (including a sole proprietorship, corporation, partnership or other legal entity) which is owned and operated independently from all other businesses, which has the purpose of making a profit, and which has fifty or fewer employees.
STAGED EVACUATION. A method of emergency response, that engages building components and trained staff to provide occupant safety during an emergency. Emergency response involves moving or holding certain occupants at temporary locations for a brief period of time before evacuating the building. This response is used by ambulatory surgery facility and assisted living facilities to protect the health and safety of fragile occupants and residents.
WALL, LOAD-BEARING. Any wall meeting either of the following classifications:
1. Any metal or wood stud wall that supports more than 100 pounds per linear foot (1459 N/m) of vertical load in addition to its own weight.
2. Any masonry or concrete, or mass timber wall that supports more than 200 pounds per linear foot (2919 N/m) of vertical load in addition to its own weight.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-0403Section 403—High-rise buildings.
403.3.2 Water supply to required fire pumps. In all buildings that are more than 420 feet (128 m) in building height, and buildings of Type IV-A and IV-B that are more than 120 feet in building height, required fire pumps shall be supplied by connections to not fewer than two water mains located in different streets. Separate supply piping shall be provided between each connection to the water main and the pumps. Each connection and the supply piping between the connection and the pumps shall be sized to supply the flow and pressure required for the pumps to operate.
EXCEPTION:
Two connections to the same main shall be permitted provided that the main is valved such that an interruption can be isolated so that the water supply will continue without interruption through not fewer than one of the connections.
403.5.4 Smokeproof enclosures. Every required interior exit stairway serving floors more than 75 feet (22,860 mm) above the lowest level of fire department vehicle access shall be a smokeproof enclosure in accordance with Sections 909.20 and 1023.11.
EXCEPTION:
Unless required by other sections of this code, portions of such stairways which extend to serve floors below the level of exit discharge need not comply with Sections 909.20 and 1023.11 provided the portion of the stairway below is separated from the level of exit discharge with a 1-hour fire barrier.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-0504Section 504—Building height and number of stories.
Table 504.3
Allowable Building Height in Feet Above Grade Planea
Occupancy Classification
Type of Construction
See
Footnotes
Type I
Type II
Type III
Type IV
Type V
A
B
A
B
A
B
A
B
C
HT
A
B
A, B, E, F, M, S, U
NSb
UL
160
65
55
65
55
65
65
65
65
50
40
S
UL
180
85
75
85
75
270
180
85
85
70
60
H-1, H-2, H-3, H-5
NSc,d
UL
160
65
55
65
55
120
90
65
65
50
40
S
 
 
 
 
 
 
 
 
 
 
 
 
H-4
NSc,d
UL
160
65
55
65
55
65
65
65
65
50
40
S
UL
180
85
75
85
75
140
100
85
85
70
60
I-1 Condition 1, I-3
NSd,e
UL
160
65
55
65
55
65
65
65
65
50
40
S
UL
180
85
75
85
75
180
120
85
85
70
60
I-1 Condition 2, I-2
NSd,e,f
UL
160
65
55
65
55
65
65
65
65
50
40
S
UL
180
85
 
 
 
 
 
 
 
 
 
I-4
NSd,g
UL
160
65
55
65
55
65
65
65
65
50
40
S
UL
180
85
75
85
75
180
120
85
85
70
60
R
NSd
UL
160
65
55
65
55
65
65
65
65
50
40
S13R
60
60
60
60
60
60
60
60
60
60
60
60
S
UL
180
85
75
85
75
270
180
85
85
70
60
For SI: 1 foot = 304.8 mm.
UL = Unlimited; NS = Buildings not equipped throughout with an automatic sprinkler system; S = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1; S13R = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.2.
 
a
See Chapters 4 and 5 for specific exceptions to the allowable height in this chapter.
 
b
See Section 903.2 for the minimum thresholds for protection by an automatic sprinkler system for specific occupancies.
 
c
New Group H occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.5.
 
d
The NS value is only for use in evaluation of existing building height in accordance with the International Existing Building Code.
 
e
New Group I-1 and I-3 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6. For new Group I-1 occupancies Condition 1, see Exception 1 of Section 903.2.6.
 
f
New and existing Group I-2 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6 and Section 1103.5 of the International Fire Code.
 
g
For new Group I-4 occupancies, see Exceptions 2 and 3 of Section 903.2.6.
 
h
New Group R occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.8.
Table 504.4
Allowable Number of Stories Above Grade Planea,b
Occupancy Classification
Type of Construction
See
Footnotes
Type I
Type II
Type III
Type IV
Type V
A
B
A
B
A
B
A
B
C
HT
A
B
A-1
NS
UL
5
3
2
3
2
3
3
3
3
2
1
S
UL
6
4
3
4
3
9
6
4
4
3
2
A-2
NS
UL
11
3
2
3
2
3
3
3
3
2
1
S
UL
12
4
3
4
3
18
12
6
4
3
2
A-3
NS
UL
11
3
2
3
2
3
3
3
3
2
1
S
UL
12
4
3
4
3
18
12
6
4
3
2
A-4
NS
UL
11
3
2
3
2
3
3
3
3
2
1
S
UL
12
4
3
4
3
18
12
6
4
3
2
A-5
NS
UL
UL
UL
UL
UL
UL
1
1
1
UL
UL
UL
S
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
B
NS
UL
11
5
3
5
3
5
5
5
5
3
2
S
UL
12
6
4
6
4
18
12
9
6
4
3
E
NS
UL
5
3
2
3
2
3
3
3
3
1
1
S
UL
6
4
3
4
3
9
6
4
4
2
2
F-1
NS
UL
11
4
2
3
2
3
3
3
 
2
1
S
UL
12
5
3
4
3
10
7
5
5
3
2
F-2
NS
UL
11
5
3
4
3
5
5
5
5
3
2
S
UL
12
6
4
5
4
12
8
6
6
4
3
H-1
NSc,d
1
1
1
1
1
1
NP
NP
NP
1
1
NP
S
 
 
 
 
 
 
1
1
1
 
 
 
H-2
NSc,d
UL
3
2
1
2
1
1
1
1
2
1
1
S
 
 
 
 
 
 
2
2
2
 
 
 
H-3
NSc,d
UL
6
4
2
4
2
3
3
3
4
2
1
S
 
 
 
 
 
 
4
4
4
 
 
 
H-4
NSc,d
UL
7
5
3
5
3
5
5
5
5
3
2
S
UL
8
6
4
6
4
8
7
6
6
4
3
H-5
NSc,d
4
4
3
3
3
3
2
2
2
3
3
2
S
 
 
 
 
 
 
3
3
3
 
 
 
I-1 Condition 1
NSd,e
UL
9
4
3
4
3
4
4
4
4
3
2
S
UL
10
5
4
5
4
10
7
5
5
4
3
I-1 Condition 2
NSd,e
UL
9
4
3
4
3
3
3
3
4
3
2
S
UL
10
5
 
 
 
10
6
4
 
 
 
I-2
NSd,f
UL
4
2
1
1
NP
NP
NP
NP
1
1
NP
S
UL
5
3
 
 
 
7
5
1
 
 
 
I-3
NSd,e
UL
4
2
1
2
1
2
2
2
2
2
1
S
UL
5
3
2
3
2
7
5
3
3
3
2
I-4
NSd,g
UL
5
3
2
3
2
3
3
3
3
1
1
S
UL
6
4
3
4
3
9
6
4
4
2
2
M
NS
UL
11
4
2
4
2
4
4
4
4
3
1
S
UL
12
5
3
5
3
12
8
6
5
4
2
R-1h
NSd
UL
11
4
4
4
4
4
4
4
4
3
2
S13R
4
4
 
 
 
 
 
 
 
 
4
3
S
UL
12
5
5
5
5
18
12
8
5
4
3
R-2h
NSd
UL
11
4
4
4
4
4
4
4
4
3
2
S13R
4
4
4
 
 
 
 
 
 
 
4
3
 
S
UL
12
5
5
5
5
18
12
8
5
4
3
R-3h
NSd
UL
11
4
4
4
4
4
4
4
4
3
3
S13D
4
4
 
 
 
 
 
 
 
 
3
3
S13R
4
4
 
 
 
 
 
 
 
 
4
4
S
UL
12
5
5
5
5
18
12
5
5
4
4
R-4h
NSd
UL
11
4
4
4
4
4
4
4
4
3
2
S13D
4
4
 
 
 
 
 
 
 
 
3
2
S13R
4
4
 
 
 
 
 
 
 
 
4
3
S
UL
12
5
5
5
5
18
12
5
5
4
3
S-1
NS
UL
11
4
2
3
2
4
4
4
4
3
1
S
UL
12
5
3
4
3
10
7
5
5
4
2
S-2
NS
UL
11
5
3
4
3
4
4
4
4
4
2
S
UL
12
6
4
5
4
12
8
5
5
5
3
U
NS
UL
5
4
2
3
2
4
4
4
4
2
1
S
UL
6
5
3
4
3
9
6
5
5
3
2
UL = Unlimited; NP = Not permitted; NS = Buildings not equipped throughout with an automatic sprinkler system; S = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1; S13R = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.2.
 
a
See Chapters 4 and 5 for specific exceptions to the allowable height in this chapter.
 
b
See Section 903.2 for the minimum thresholds for protection by an automatic sprinkler system for specific occupancies.
 
c
New Group H occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.5.
 
d
The NS value is only for use in evaluation of existing building height in accordance with the International Existing Building Code.
 
e
New Group I-1 and I-3 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6. For new Group I-1 occupancies Condition 1, see Exception 1 of Section 903.2.6.
 
f
New and existing Group I-2 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6 and Section 1103.5 of the International Fire Code.
 
g
For new Group I-4 occupancies, see Exceptions 2 and 3 of Section 903.2.6.
 
h
New Group R occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.8.
504.4.1 Stair enclosure pressurization increase. For Group R1 and R2 occupancies in buildings of Type VA construction equipped throughout with an approved automatic sprinkler system in accordance with Section 903.3.1.1, the maximum number of stories permitted in Section 504.2 may be increased by one provided the interior exit stairways and ramps are pressurized in accordance with Section 909. Legally required standby power shall be provided for buildings constructed in compliance with this section and be connected to stairway shaft pressurization equipment, elevators and lifts used for accessible means of egress, hoistway pressurization equipment (if provided) and other life safety equipment as determined by the authority having jurisdiction. For the purposes of this section, legally required standby power shall comply with 2014 NEC Section 701.12, options (A), (B), (C), (D), (F), or (G) or subsequent revised section number(s).
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-0506((Reserved.))Section 506—Building area.
Table 506.2
Allowable Area Factor (At = NS, S1, S13R, S13D or SM, as applicable) In Square Feeta,b
Occupancy Classification
 
Type of Construction
See
Footnotes
Type I
Type II
Type III
Type IV
Type V
A
B
A
B
A
B
A
B
C
HT
A
B
A-1
NS
UL
UL
15,500
8,500
14,000
8,500
45,000
30,000
18,000
15,000
11,500
5,500
S1
UL
UL
62,000
34,000
56,000
34,000
180,000
120,000
75,000
60,000
46,000
22,000
SM
UL
UL
46,500
25,500
42,000
25,500
135,000
90,000
56,250
45,000
34,500
16,500
A-2
NS
UL
UL
15,500
9,500
14,000
9,500
45,000
30,000
18,750
15,000
11,500
6,000
S1
UL
UL
62,000
38,000
56,000
38,000
180,000
120,000
75,000
60,000
46,000
24,000
SM
UL
UL
46,500
28,500
42,000
28,500
135,000
90,000
56,250
45,000
34,500
18,000
A-3
NS
UL
UL
15,500
9,500
14,000
9,500
45,000
30,000
18,750
15,000
11,500
6,000
S1
UL
UL
62,000
38,000
56,000
38,000
180,000
120,000
75,000
60,000
46,000
24,000
SM
UL
UL
46,500
28,500
42,000
28,500
135,000
90,000
56,000
45,000
34,500
18,000
A-4
NS
UL
UL
15,500
9,500
14,000
9,500
45,000
30,000
18,750
15,000
11,500
6,000
S1
UL
UL
62,000
38,000
56,000
38,000
180,000
120,000
75,000
60,000
46,000
24,000
SM
UL
UL
46,500
28,500
42,000
28,500
135,000
90,000
56,250
45,000
34,500
18,000
A-5
NS
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
S1
 
 
 
 
 
 
 
 
 
 
 
 
SM
 
 
 
 
 
 
 
 
 
 
 
 
B
NS
UL
UL
37,500
23,000
28,500
19,000
108,000
75,000
45,000
36,000
18,000
9,000
S1
UL
UL
150,000
92,000
114,000
76,000
432,000
288,000
180,000
144,000
72,000
36,000
SM
UL
UL
112,500
69,000
85,500
57,000
324,000
216,000
135,000
108,000
54,000
27,000
E
NS
UL
UL
26,500
14,500
23,500
14,500
76,500
51,000
31,875
25,500
18,500
9,500
S1
UL
UL
106,000
58,000
94,000
58,000
306,000
204,000
127,500
102,000
74,000
38,000
SM
UL
UL
79,500
43,500
70,500
43,500
229,500
153,000
95,625
76,500
55,500
28,500
F-1
NS
UL
UL
25,000
15,500
19,000
12,000
100,500
67,000
41,875
33,500
14,000
8,500
S1
UL
UL
100,000
62,000
76,000
48,000
402,000
268,000
167,500
134,000
56,000
34,000
SM
UL
UL
75,000
46,500
57,000
36,000
301,500
201,000
125,625
100,500
42,000
25,500
F-2
NS
UL
UL
37,500
23,000
28,500
18,000
151,500
101,000
63,125
50,500
21,000
13,000
S1
UL
UL
150,000
92,000
114,000
72,000
606,000
404,000
252,500
202,000
84,000
52,000
SM
UL
UL
112,500
69,000
85,500
54,000
454,500
303,000
189,375
151,500
63,000
39,000
H-1
NSc
21,000
16,500
11,000
7,000
9.500
7,000
10,500
10,500
10,000
10,500
7,500
NP
S1
 
 
 
 
 
 
 
 
 
 
 
 
H-2
NSc
21,000
16,500
11,000
7,000
9.500
7,000
10,500
10,500
10,000
10,500
7,500
3,000
S1
 
 
 
 
 
 
 
 
 
 
 
 
SM
 
 
 
 
 
 
 
 
 
 
 
 
H-3
NSc
UL
60,000
26,500
14,000
17,500
13,000
25,000
25,000
25,000
25,500
10,000
5,000
S1
 
 
 
 
 
 
 
 
 
 
 
 
SM
 
 
 
 
 
 
 
 
 
 
 
 
H-4
NSc,d
UL
UL
37,500
17,500
28,500
17,500
75,000
54,000
40,500
36,000
18,000
6,500
S1
UL
UL
150,000
70,000
114,000
70,000
288,000
216,000
162,000
144,000
72,000
26,000
SM
UL
UL
112,500
52,500
85,500
52,500
216,000
162,000
121,500
108,000
54,000
19,500
H-5
NSc,d
UL
UL
37,500
23,000
28,500
19,000
72,000
54,000
40,500
36,000
18,000
9,000
S1
UL
UL
150,000
92,000
114,000
76,000
288,000
216,000
162,000
144,000
72,000
36,000
SM
UL
UL
112,500
69,000
85,500
57,000
216,000
162,000
121,500
108,000
54,000
27,000
Occupancy Classification
 
Type of Construction
See
Footnotes
Type I
Type II
Type III
Type IV
Type V
A
B
A
B
A
B
A
B
C
HT
A
B
I-1
NSd, e
UL
55,000
19,000
10,000
16,500
10,000
54,000
36,000
18,000
18,000
10,500
4,500
S1
UL
220,000
76,000
40,000
66,000
40,000
216,000
144,000
72,000
72,000
42,000
18,000
SM
UL
165,000
57,000
30,000
49,500
30,000
162,000
108,000
54,000
54,000
31,500
13,500
I-2
NSd, f
UL
UL
15,000
11,000
12,000
NP
36,000
24,000
12,000
12,000
9,500
NP
S1
UL
UL
60,000
44,000
48,000
NP
144,000
96,000
48,000
48,000
38,000
NP
SM
UL
UL
45,000
33,000
36,000
NP
108,000
72,000
36,000
36,000
28,500
NP
I-3
NSd, e
UL
UL
15,000
10,000
10,500
7,500
36,000
24,000
12,000
12,000
7,500
5,000
S1
UL
UL
45,000
40,000
42,000
30,000
144,000
96,000
48,000
48,000
30,000
20,000
SM
UL
UL
45,000
30,000
31,500
22,500
108,000
72,000
36,000
36,000
22,500
15,000
I-4
NSd, g
UL
60.500
26,500
13,000
23,500
13,000
76,500
51,000
25,500
25,500
18,500
9,000
S1
UL
121,000
106,000
52,000
94,000
52,000
306,000
204,000
102,000
102,000
74,000
36,000
SM
UL
181,500
79,500
39,000
70,500
39,000
229,500
153,000
76,500
76,500
55,500
27,000
M
NS
UL
UL
21,500
12,500
18,500
12,500
61,500
41,000
25,625
20,500
14,000
9,000
S1
UL
UL
86,000
50,000
74,000
50,000
246,000
164,000
102,500
82,000
56,000
36,000
SM
UL
UL
64,500
37,500
55,500
37,500
184,500
123,000
76,875
61,500
42,000
27,000
R-1
NSd, h
UL
UL
24,000
16,000
24,000
16,000
61,500
41,000
25,625
20,500
12,000
7,000
S13R
 
 
 
 
 
 
 
 
 
 
 
 
S1
UL
UL
96,000
64,000
96,000
64,000
246,000
164,000
102,500
82,000
48,000
28,000
SM
UL
UL
72,000
48,000
72,000
48,000
184,500
123,000
76,875
61,500
36,000
21,000
R-2
NSd, h
UL
UL
24,000
16,000
24,000
16,000
61,500
41,000
25.625
20,500
12,000
7,000
S13R
S1
UL
UL
96,000
64,000
96,000
64,000
246,000
164,000
102,500
82,000
48,000
28,000
SM
UL
UL
72,000
48,000
72,000
48,000
184,500
123,000
76,875
61,500
36,000
21,000
R-3
NSd, h
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
UL
S13R
 
 
 
 
 
 
 
 
 
 
 
 
S1
 
 
 
 
 
 
 
 
 
 
 
 
SM
 
 
 
 
 
 
 
 
 
 
 
 
R-4
NSd, h
UL
UL
24,000
16,000
24,000
16,000
61,000
41,000
25,625
20,500
12,000
7,000
S13R
 
 
 
 
 
 
 
 
 
 
 
 
S1
UL
UL
96,000
64,000
96,000
64,000
246,000
164,000
102,500
82,000
48,000
28,000
SM
UL
UL
72,000
48,000
72,000
48,000
184,500
123,000
76,875
61,500
36,000
21,000
S-1
NS
UL
48,000
26,000
17,500
26,000
17,500
76,500
51,000
31,875
25,500
14,000
9,000
S1
UL
192,000
104,000
70,000
104,000
70,000
306,000
204,000
127,500
102,000
56,000
36,000
SM
UL
144,000
78,000
52,500
78,000
52,500
229,500
153,000
95,625
76,500
42,000
27,000
S-2
NS
UL
79,000
39,000
26,000
39,000
26,000
115,500
77,000
48,125
38,500
21,000
13,500
S1
UL
316,000
156,000
104,000
156,000
104,000
462,000
308,000
192,500
154,000
84,000
54,000
SM
UL
237,000
117,000
78,000
117,000
78,000
346,500
231,000
144,375
115,500
63,000
40,500
U
NS
UL
35,500
19,000
8,500
14,000
8,500
54,000
36,000
22,500
18,000
9,000
5,500
S1
UL
142,000
76,000
34,000
56,000
34,000
216,000
144,000
90,000
72,000
36,000
22,000
SM
UL
106,500
57,000
25,500
42,000
25,500
162,000
108,000
67,500
54,000
27,000
16,500
For SI: 1 square foot = 0.0929 m2.
UL = Unlimited; NP = Not permitted; NS = Buildings not equipped throughout with an automatic sprinkler system; S1 = Buildings a maximum of one story above grade plane equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1; SM = Buildings two or more stories above grade plane equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.1; S13R = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.2; S13D = Buildings equipped throughout with an automatic sprinkler system installed in accordance with Section 903.3.1.3.
 
a
See Chapters 4 and 5 for specific exceptions to the allowable height in this chapter.
 
b
See Section 903.2 for the minimum thresholds for protection by an automatic sprinkler system for specific occupancies.
 
c
New Group H occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.5.
 
d
The NS value is only for use in evaluation of existing building area in accordance with the International Existing Building Code.
 
e
New Group I-1 and I-3 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6. For new Group I-1 occupancies Condition 1, see Exception 1 of Section 903.2.6.
 
f
New and existing Group I-2 occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.6 and Section 1103.5 of the International Fire Code.
 
g
For new Group I-4 occupancies, see Exceptions 2 and 3 of Section 903.2.6.
 
h
New Group R occupancies are required to be protected by an automatic sprinkler system in accordance with Section 903.2.8.
 
i
The maximum allowable area for a single-story nonsprinklered Group U greenhouse is permitted to be 9,000 square feet, or the allowable area shall be permitted to comply with Table C102.1 of Appendix C.
NEW SECTION
WAC 51-50-0508Section 508—Mixed use and occupancy.
508.4.4.1 Construction. Required separations shall be fire barriers constructed in accordance with Section 707 or horizontal assemblies constructed in accordance with Section 711, or both, so as to completely separate adjacent occupancies. Mass timber elements serving as fire barriers or horizontal assemblies to separate occupancies in Type IV-B or IV-C construction shall be separated from the interior of the building with an approved thermal barrier consisting of a minimum of 1/2 inch (12.7 mm) gypsum board or a material that is tested in accordance with and meets the acceptance criteria of both the Temperature Transmission Fire Test and the Integrity Fire Test of NFPA 275.
AMENDATORY SECTION(Amending WSR 13-04-067, filed 2/1/13, effective 7/1/13)
WAC 51-50-0509Section 509—Incidental uses.
509.4.1.1 Type IV-B and IV-C construction. Where Table 509 specifies a fire-resistance-rated separation, mass timber elements serving as fire barriers or a horizontal assembly in Type IV-B or IV-C construction shall be separated from the interior of the incidental use with an approved thermal barrier consisting of a minimum of 1/2 inch (12.7 mm) gypsum board or a material that is tested in accordance with and meets the acceptance criteria of both the Temperature Transmission Fire Test and the Integrity Fire Test of NFPA 275.
Table 509
Incidental Uses
Room or Area
Separation and/or Protection
Dry type transformers over 112.5 kVA and required to be in a fire resistant room per NEC (NFPA 70) Section 450.21 (B)1
1 hour or provide automatic sprinkler system
1
Dry type transformers rated over 35,000 volts and oil-insulated transformers shall be installed in a transformer vault complying with NFPA 70.
(Remainder of table unchanged)
NEW SECTION
WAC 51-50-0601Section 601—General.
Table 601
Fire-resistance Rating Requirements for Building Elements (hours)
Building Element
Type I
Type II
Type III
Type IV
Type V
A
B
A
B
A
B
A
B
C
HT
A
B
Primary structural framef (see Section 202)
3a
2a
1
0
1b
0
3a
2a
2a
HT
1
0
Bearing walls
 
 
 
 
 
 
 
 
 
 
 
 
Exteriore, f
3
2
1
0
2
2
3
2
2
2
1
0
Interior
3a
2a
1
0
1
0
3
2
2
1/HT
1
0
Nonbearing walls and partitions exterior
See Table 602
Nonbearing walls and partitions interiord
0
0
0
0
0
0
0
0
0
See Section 602.4.4.6
0
0
Floor construction and associated secondary members (see Section 202)
2
2
1
0
1
0
2
2
2
HT
1
0
Roof construction and associated secondary members (see Section 202)
1 1/2b
1b,c
1b,c
0c
1b,c
0
1 1/2
1
1
HT
1b,c
0
For SI: 1 foot = 304.8 mm.
 
a
Roof supports: Fire-resistance ratings of primary structural frame and bearing walls are permitted to be reduced by 1 hour where supporting a roof only.
 
b
Except in Groups F-1, H, M and S-1 occupancies, fire protection of structural members in roof construction shall not be required, including protection of primary structural frame members, roof framing and decking where every part of the roof construction is 20 feet or more above any floor immediately below. Fire-retardant-treated wood members shall be allowed to be used for such unprotected members.
 
c
In all occupancies, heavy timber complying with Section 2304.11 shall be allowed where a 1-hour or less fire-resistance rating is required.
 
d
Not less than the fire-resistance rating required by other sections of this code.
 
e
Not less than the fire-resistance rating based on fire separation distance (see Table 602).
 
f
Not less than the fire-resistance rating as referenced in Section 704.10.
NEW SECTION
WAC 51-50-0602Section 602—Construction classification.
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 He
Occupancy Group F-1, M, S-1f
Occupancy Group A, B, E, F-2, I, Ri,
S-2, Uh
X < 5b
All
3
2
1
5 ≤ X < 10
IA, IVA
3
2
11
 
Others
2
1
 
10 ≤ X < 30
IA, IB, IVA, IVB
2
1
1c
 
IIB, VB
1
0
0
 
Others
1
1
1c
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 Section 415.6.
 
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
For a building containing only a Group U occupancy private garage or carport, the exterior wall shall not be required to have a fire-resistance rating where the fire separation distance is 5 feet (1523 mm) or greater.
602.4 Type IV. Type IV construction is that type of construction in which the building elements are mass timber or noncombustible materials and have fire-resistance ratings in accordance with Table 601. Mass timber elements shall meet the fire-resistance rating requirements of this section based on either the fire-resistance rating of the noncombustible protection, the mass timber, or a combination of both and shall be determined in accordance with Section 703.2 or 703.3. The minimum dimensions and permitted materials for building elements shall comply with the provisions of this section including Table 602.4.4 and Section 2304.11. Mass timber elements of Types IV-A, IV-B and IV-C construction shall be protected with noncombustible protection applied directly to the mass timber in accordance with Sections 602.4.1 through 602.4.3. The time assigned to the noncombustible protection shall be determined in accordance with Section 703.8 and comply with 722.7.
Cross-laminated timber shall be labeled as conforming to ANSI/APA PRG 320 as referenced in Section 2303.1.4.
Exterior load-bearing walls and nonload-bearing walls shall be mass timber construction, or shall be of noncombustible construction.
EXCEPTION:
Exterior load-bearing walls and nonload-bearing walls of Type IV-HT Construction in accordance with Section 602.4.4.
The interior building elements, including nonload-bearing walls and partitions, shall be of mass timber construction or of noncombustible construction.
EXCEPTION:
Interior building elements and nonload-bearing walls and partitions of Type IV-HT Construction in accordance with Section 602.4.4.
Combustible concealed spaces are not permitted except as otherwise indicated in Sections 602.4.1 through 602.4.4. Combustible stud spaces within light frame walls of Type IV-HT construction shall not be considered concealed spaces, but shall comply with Section 718.
In buildings of Type IV-A, B, and C, construction with an occupied floor located more than 75 feet above the lowest level of fire department access, up to and including 12 stories or 180 feet above grade plane, mass timber interior exit and elevator hoistway enclosures shall be protected in accordance with Section 602.4.1.2. In buildings greater than 12 stories or 180 feet above grade plane, interior exit and elevator hoistway enclosures shall be constructed of noncombustible materials.
602.4.1 Type IV-A. Building elements in Type IV-A construction shall be protected in accordance with Sections 602.4.1.1 through 602.4.1.6. The required fire-resistance rating of noncombustible elements and protected mass timber elements shall be determined in accordance with Section 703.2 or Section 703.3.
602.4.1.1 Exterior protection. The outside face of exterior walls of mass timber construction shall be protected with noncombustible protection with a minimum assigned time of 40 minutes as determined in Section 722.7.1. All components of the exterior wall covering, shall be of noncombustible material except water resistive barriers having a peak heat release rate of less than 150 kW/m2, a total heat release of less than 20 MJ/m2 and an effective heat of combustion of less than 18 MJ/kg as determined in accordance with ASTM E1354 and having a flame spread index of 25 or less and a smoke-developed index of 450 or less as determined in accordance with ASTM E84 or UL 723. The ASTM E1354 test shall be conducted on specimens at the thickness intended for use, in the horizontal orientation and at an incident radiant heat flux of 50 kW/m2.
602.4.1.2 Interior protection. Interior faces of all mass timber elements, including the inside faces of exterior mass timber walls and mass timber roofs, shall be protected with materials complying with Section 703.5.
602.4.1.2.1 Protection time. Noncombustible protection shall contribute a time equal to or greater than times assigned in Table 722.7.1(1), but not less than 80 minutes. The use of materials and their respective protection contributions listed in Table 722.7.1(2), shall be permitted to be used for compliance with Section 722.7.1.
602.4.1.3 Floors. The floor assembly shall contain a noncombustible material not less than 1 inch in thickness above the mass timber. Floor finishes in accordance with Section 804 shall be permitted on top of the noncombustible material. The underside of floor assemblies shall be protected in accordance with 602.4.1.2.
602.4.1.4 Roofs. The interior surfaces of roof assemblies shall be protected in accordance with Section 602.4.1.2. Roof coverings in accordance with Chapter 15 shall be permitted on the outside surface of the roof assembly.
602.4.1.5 Concealed spaces. Concealed spaces shall not contain combustibles other than electrical, mechanical, fire protection, or plumbing materials and equipment permitted in plenums in accordance with Section 602 of the International Mechanical Code, and shall comply with all applicable provisions of Section 718. Combustible construction forming concealed spaces shall be protected in accordance with Section 602.4.1.2.
602.4.1.6 Shafts. Shafts shall be permitted in accordance with Sections 713 and 718. Both the shaft side and room side of mass timber elements shall be protected in accordance with Section 602.4.1.2.
602.4.2 Type IV-B. Building elements in Type IV-B construction shall be protected in accordance with Sections 602.4.2.1 through 602.4.2.6. The required fire-resistance rating of noncombustible elements or mass timber elements shall be determined in accordance with Section 703.2 or 703.3.
602.4.2.1 Exterior protection. The outside face of exterior walls of mass timber construction shall be protected with noncombustible protection with a minimum assigned time of 40 minutes as determined in Section 722.7.1. All components of the exterior wall covering shall be of noncombustible material except water resistive barriers having a peak heat release rate of less than 150 kW/m2, a total heat release of less than 20 MJ/m2 and an effective heat of combustion of less than 18 MJ/kg as determined in accordance with ASTM E1354, and having a flame spread index of 25 or less and a smoke-developed index of 450 or less as determined in accordance with ASTM E84 or UL 723. The ASTM E1354 test shall be conducted on specimens at the thickness intended for use, in the horizontal orientation and at an incident radiant heat flux of 50 kW/m2.
602.4.2.2 Interior protection. Interior faces of all mass timber elements, including the inside face of exterior mass timber walls and mass timber roofs, shall be protected, as required by this section, with materials complying with Section 703.5.
602.4.2.2.1 Protection time. Noncombustible protection shall contribute a time equal to or greater than times assigned in Table 722.7.1(1), but not less than 80 minutes. The use of materials and their respective protection contributions listed in Table 722.7.1(2), shall be permitted to be used for compliance with Section 722.7.1.
602.4.2.2.2 Protected area. All interior faces of all mass timber elements shall be protected in accordance with Section 602.4.2.2.1, including the inside face of exterior mass timber walls and mass timber roofs.
EXCEPTION:
Unprotected portions of mass timber ceilings and walls complying with Section 602.4.2.2.4 and the following:
 
1. Unprotected portions of mass timber ceilings, including attached beams, shall be permitted and shall be limited to an area equal to 20% of the floor area in any dwelling unit or fire area; or
 
2. Unprotected portions of mass timber walls, including attached columns, shall be permitted and shall be limited to an area equal to 40% of the floor area in any dwelling unit or fire area; or
 
3. Unprotected portions of both walls and ceilings of mass timber, including attached columns and beams, in any dwelling unit or fire area shall be permitted in accordance with Section 602.4.2.2.3.
 
4. Mass timber columns and beams which are not an integral portion of walls or ceilings, respectively, shall be permitted to be unprotected without restriction of either aggregate area or separation from one another.
602.4.2.2.3 Mixed unprotected areas. In each dwelling unit or fire area, where both portions of ceilings and portions of walls are unprotected, the total allowable unprotected area shall be determined in accordance with Equation 6-1.
(Equation 6-1)
(Utc/Uac) + (Utw/Uaw) ≤ 1
where:
 
Utc
=
Total unprotected mass timber ceiling areas;
 
Uac
=
Allowable unprotected mass timber ceiling area conforming to Section 602.4.2.2.2, Exception 1;
 
Utw
=
Total unprotected mass timber wall areas;
 
Uaw
=
Allowable unprotected mass timber wall area conforming to Section 602.4.2.2.2, Exception 2.
602.4.2.2.4 Separation distance between unprotected mass timber elements. In each dwelling unit or fire area, unprotected portions of mass timber walls and ceilings shall be not less than 15 feet from unprotected portions of other walls and ceilings, measured horizontally along the ceiling and from other unprotected portions of walls measured horizontally along the floor.
602.4.2.3 Floors. The floor assembly shall contain a noncombustible material not less than 1 inch in thickness above the mass timber. Floor finishes in accordance with Section 804 shall be permitted on top of the noncombustible material. The underside of floor assemblies shall be protected in accordance with Section 602.4.1.2.
602.4.2.4 Roofs. The interior surfaces of roof assemblies shall be protected in accordance with Section 602.4.2.2 except, in nonoccupiable spaces, they shall be treated as a concealed space with no portion left unprotected. Roof coverings in accordance with Chapter 15 shall be permitted on the outside surface of the roof assembly.
602.4.2.5 Concealed spaces. Concealed spaces shall not contain combustibles other than electrical, mechanical, fire protection, or plumbing materials and equipment permitted in plenums in accordance with Section 602 of the International Mechanical Code, and shall comply with all applicable provisions of Section 718. Combustible construction forming concealed spaces shall be protected in accordance with Section 602.4.1.2.
602.4.2.6 Shafts. Shafts shall be permitted in accordance with Sections 713 and 718. Both the shaft side and room side of mass timber elements shall be protected in accordance with Section 602.4.1.2.
602.4.3 Type IV-C. Building elements in Type IV-C construction shall be protected in accordance with Sections 602.4.3.1 through 602.4.3.6. The required fire-resistance rating of building elements shall be determined in accordance with Sections 703.2 or 703.3.
602.4.3.1 Exterior protection. The exterior side of walls of combustible construction shall be protected with noncombustible protection with a minimum assigned time of 40 minutes as determined in Section 722.7.1. All components of the exterior wall covering, shall be of noncombustible material except water resistive barriers having a peak heat release rate of less than 150 kW/m2, a total heat release of less than 20 MJ/m2 and an effective heat of combustion of less than 18 MJ/kg as determined in accordance with ASTM E1354 and having a flame spread index of 25 or less and a smoke-developed index of 450 or less as determined in accordance with ASTM E84 or UL 723. The ASTM E1354 test shall be conducted on specimens at the thickness intended for use, in the horizontal orientation and at an incident radiant heat flux of 50 kW/m2.
602.4.3.2 Interior protection. Mass timber elements are permitted to be unprotected.
602.4.3.3 Floors. Floor finishes in accordance with Section 804 shall be permitted on top of the floor construction.
602.4.3.4 Roofs. Roof coverings in accordance with Chapter 15 shall be permitted on the outside surface of the roof assembly.
602.4.3.5 Concealed spaces. Concealed spaces shall not contain combustibles other than electrical, mechanical, fire protection, or plumbing materials and equipment permitted in plenums in accordance with Section 602 of the International Mechanical Code, and shall comply with all applicable provisions of Section 718. Combustible construction forming concealed spaces shall be protected with noncombustible protection with a minimum assigned time of 40 minutes as determined in Section 722.7.1.
602.4.3.6 Shafts. Shafts shall be permitted in accordance with Sections 713 and 718. Shafts and elevator hoistway and interior exit stairway enclosures shall be protected with noncombustible protection with a minimum assigned time of 40 minutes as determined in Section 722.7.1, on both the inside of the shaft and the outside of the shaft.
602.4.4 Type IV-HT. Type IV-HT construction (Heavy Timber, HT) is that type of construction in which the exterior walls are of noncombustible materials and the interior building elements are of solid wood, laminated heavy timber or structural composite lumber (SCL), without concealed spaces. The minimum dimensions for permitted materials including solid timber, glued-laminated timber, structural composite lumber (SCL) and cross-laminated timber (CLT) and details of Type IV construction shall comply with the provisions of this section, including Table 602.4.4 and Section 2304.11. Exterior walls complying with Section 602.4.4.1 or 602.4.4.2 shall be permitted. Interior walls and partitions not less than 1 hour fire-resistance rating or heavy timber conforming with Section 602.4.4.8.1 shall be permitted. Cross-laminated timber (CLT) dimensions used in this section are actual dimensions. Lumber decking shall be in accordance with Section 2304.9.
602.4.4.1 Fire-retardant-treated wood in exterior walls. Fire-retardant-treated wood framing and sheathing complying with Section 2303.2 shall be permitted within exterior wall assemblies not less than 6 inches (152 mm) in thickness with a 2-hour rating or less.
602.4.4.2 Cross-laminated timber in exterior walls. Cross-laminated timber complying with Section 2303.1.4 shall be permitted within exterior wall assemblies not less than 6 inches (152 mm) in thickness with a 2-hour rating or less, provided the exterior surface of the cross-laminated timber is protected by one of the following:
1. Fire-retardant-treated wood sheathing complying with Section 2303.2 and not less than 15/32 inch (12 mm) thick;
2. Gypsum board not less than 1/2 inch (12.7 mm) thick; or
3. A noncombustible material.
602.4.4.3 Columns. Wood columns shall be sawn or glued laminated and shall be not less than 8 inches (203 mm), nominal, in any dimension where supporting floor loads and not less than 6 inches (152 mm) nominal in width and not less than 8 inches (203 mm) nominal in depth where supporting roof and ceiling loads only. Columns shall be continuous or superimposed and connected in an approved manner. Protection in accordance with Section 704.2 is not required.
602.4.4.4 Floor framing. Wood beams and girders shall be of sawn or glued-laminated timber and shall be not less than 6 inches (152 mm) nominal in width and not less than 10 inches (254 mm) nominal in depth. Framed sawn or glued-laminated timber arches, which spring from the floor line and support floor loads, shall be not less than 8 inches (203 mm) nominal in any dimension. Framed timber trusses supporting floor loads shall have members of not less than 8 inches (203 mm) nominal in any dimension.
602.4.4.5 Roof framing. Wood-frame or glued-laminated arches for roof construction, which spring from the floor line or from grade and do not support floor loads, shall have members not less than 6 inches (152 mm) nominal in width and have not less than 8 inches (203 mm) nominal in depth for the lower half of the height and not less than 6 inches (152 mm) nominal in depth for the upper half. Framed or glued-laminated arches for roof construction that spring from the top of walls or wall abutments, framed timber trusses and other roof framing, which do not support floor loads, shall have members not less than 4 inches (102 mm) nominal in width and not less than 6 inches (152 mm) nominal in depth. Spaced members shall be permitted to be composed of two or more pieces not less than 3 inches (76 mm) nominal in thickness where blocked solidly throughout their intervening spaces or where spaces are tightly closed by a continuous wood cover plate of not less than 2 inches (51 mm) nominal in thickness secured to the underside of the members. Splice plates shall be not less than 3 inches (76 mm) nominal in thickness. Where protected by approved automatic sprinklers under the roof deck, framing members shall be not less than 3 inches (76 mm) nominal in width.
602.4.4.6 Floors. Floors shall be without concealed spaces. Wood floors shall be constructed in accordance with Section 602.4.4.6.1 or 602.4.4.6.2.
602.4.4.6.1 Sawn or glued-laminated plank floors. Sawn or glued-laminated plank floors shall be one of the following:
1. Sawn or glued-laminated planks, splined or tongue-and-groove, of not less than 3 inches (76 mm) nominal in thickness covered with 1 inch (25 mm) nominal dimension tongue-and-groove flooring, laid crosswise or diagonally, 15/32 inch (12 mm) wood structural panel or 1/2 inch (12.7 mm) particleboard.
2. Planks not less than 4 inches (102 mm) nominal in width set on edge close together and well spiked and covered with 1 inch (25 mm) nominal dimension flooring or 15/32 inch (12 mm) wood structural panel or 1/2 inch (12.7 mm) particleboard.
The lumber shall be laid so that no continuous line of joints will occur except at points of support. Floors shall not extend closer than 1/2 inch (12.7 mm) to walls. Such 1/2 inch (12.7 mm) space shall be covered by a molding fastened to the wall and so arranged that it will not obstruct the swelling or shrinkage movements of the floor. Corbelling of masonry walls under the floor shall be permitted to be used in place of molding.
602.4.4.6.2 Cross-laminated timber floors. Cross-laminated timber shall be not less than 4 inches (102 mm) in thickness. Cross-laminated timber shall be continuous from support to support and mechanically fastened to one another. Cross-laminated timber shall be permitted to be connected to walls without a shrinkage gap providing swelling or shrinking is considered in the design. Corbelling of masonry walls under the floor shall be permitted to be used.
602.4.4.7 Roofs. Roofs shall be without concealed spaces and wood roof decks shall be sawn or glued laminated, splined or tongue-and-groove plank, not less than 2 inches (51 mm) nominal in thickness; 1 1/8 inch thick (32 mm) wood structural panel (exterior glue); planks not less than 3 inches (76 mm) nominal in width, set on edge close together and laid as required for floors; or of cross-laminated timber. Other types of decking shall be permitted to be used if providing equivalent fire resistance and structural properties.
Cross-laminated timber roofs shall be not less than 3 inches (76 mm) nominal in thickness and shall be continuous from support to support and mechanically fastened to one another.
602.4.4.8 Partitions and walls. Partitions and walls shall comply with Section 602.4.4.8.1 or 602.4.4.8.2.
602.4.4.8.1 Interior walls and partitions. Interior walls and partitions shall be of solid wood construction formed by not less than two layers of 1 inch (25 mm) matched boards or laminated construction 4 inches (102 mm) thick, or of 1 hour fire-resistance-rated construction.
602.4.4.8.2 Exterior walls. Exterior walls shall be of one of the following:
1. Noncombustible materials.
2. Not less than 6 inches (152 mm) in thickness and constructed of one of the following:
2.1. Fire-retardant-treated wood in accordance with Section 2303.2 and complying with Section 602.4.4.1.
2.2. Cross-laminated timber complying with Section 602.4.4.2.
602.4.4.9 Exterior structural members. Where a horizontal separation of 20 feet (6096 mm) or more is provided, wood columns and arches conforming to heavy timber sizes complying with Table 602.4.4 shall be permitted to be used externally.
NEW SECTION
WAC 51-50-0603Section 603—Combustible material in Types I and II construction.
603.1 Allowable materials. Combustible materials shall be permitted in buildings of Type I or II construction in the following applications and in accordance with Sections 603.1.1 through 603.1.3:
1. Fire-retardant-treated wood shall be permitted in:
1.1. Nonbearing partitions where the required fire-resistance rating is 2 hours or less.
1.2. Nonbearing exterior walls where fire-resistance-rated construction is not required.
1.3. Roof construction, including girders, trusses, framing and decking.
EXCEPTION:
In buildings of Type I-A construction exceeding two stories above grade plane, fire-retardant-treated wood is not permitted in roof construction where the vertical distance from the upper floor to the roof is less than 20 feet (6096 mm).
2. Thermal and acoustical insulation, other than foam plastics, having a flame spread index of not more than 25.
EXCEPTIONS:
1. Insulation placed between two layers of noncombustible materials without an intervening airspace shall be allowed to have a flame spread index of not more than 100.
 
2. Insulation installed between a finished floor and solid decking without intervening airspace shall be allowed to have a flame spread index of not more than 200.
3. Foam plastics in accordance with Chapter 26.
4. Roof coverings that have an A, B or C classification.
5. Interior floor finish and floor covering materials installed in accordance with Section 804.
6. Millwork such as doors, door frames, window sashes and frames.
7. Interior wall and ceiling finishes installed in accordance with Sections 801 and 803.
8. Trim installed in accordance with Section 806.
9. Where not installed greater than 15 feet (4572 mm) above grade, show windows, nailing or furring strips and wooden bulkheads below show windows, including their frames, aprons and show cases.
10. Finish flooring installed in accordance with Section 805.
11. Partitions dividing portions of stores, offices or similar places occupied by one tenant only and that do not establish a corridor serving an occupant load of 30 or more shall be permitted to be constructed of fire-retardant-treated wood, 1-hour fire-resistance-rated construction or of wood panels or similar light construction up to 6 feet (1829 mm) in height.
12. Stages and platforms constructed in accordance with Sections 410.3 and 410.4, respectively.
13. Combustible exterior wall coverings, balconies and similar projections and bay or oriel windows in accordance with Chapter 14.
14. Blocking such as for handrails, millwork, cabinets and window and door frames.
15. Light-transmitting plastics as permitted by Chapter 26.
16. Mastics and caulking materials applied to provide flexible seals between components of exterior wall construction.
17. Exterior plastic veneer installed in accordance with Section 2605.2.
18. Nailing or furring strips as permitted by Section 803.13.
19. Heavy timber as permitted by Notec to Table 601 and Sections 602.4.4.9 and 1406.3.
20. Aggregates, component materials and admixtures as permitted by Section 703.2.2.
21. Sprayed fire-resistant materials and intumescent and mastic fire-resistant coatings, determined on the basis of fire resistance tests in accordance with Section 703.2 and installed in accordance with Sections 1705.14 and 1705.15, respectively.
22. Materials used to protect penetrations in fire-resistance-rated assemblies in accordance with Section 714.
23. Materials used to protect joints in fire-resistance-rated assemblies in accordance with Section 715.
24. Materials allowed in the concealed spaces of buildings of Types I and II construction in accordance with Section 718.5.
25. Materials exposed within plenums complying with Section 602 of the International Mechanical Code.
26. Wall construction of freezers and coolers of less than 1,000 square feet (92.9 m2), in size, lined on both sides with noncombustible materials and the building is protected throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
NEW SECTION
WAC 51-50-0703Section 703—Fire-resistance ratings and fire tests.
703.8 Determination of noncombustible protection time contribution. The time, in minutes, contributed to the fire-resistance rating by the noncombustible protection of mass timber building elements, components, or assemblies, shall be established through a comparison of assemblies tested using procedures set forth in ASTM E119 or UL 263. The test assemblies shall be identical in construction, loading, and materials, other than the noncombustible protection. The two test assemblies shall be tested to the same criteria of structural failure.
1. Test Assembly 1 shall be without protection.
2. Test Assembly 2 shall include the representative noncombustible protection. The protection shall be fully defined in terms of configuration details, attachment details, joint sealing details, accessories and all other relevant details.
The noncombustible protection time contribution shall be determined by subtracting the fire resistance time, in minutes, of Test Assembly 1 from the fire resistance time, in minutes, of Test Assembly 2.
703.9 Sealing of adjacent mass timber elements. In buildings of Type IV-A, IV-B, and IV-C construction, sealant or adhesive shall be provided to resist the passage of air in the following locations:
1. At abutting edges and intersections of mass timber building elements required to be fire-resistance-rated.
2. At abutting intersections of mass timber building elements and building elements of other materials where both are required to be fire-resistance-rated.
Sealants shall meet the requirements of ASTM C920. Adhesives shall meet the requirements of ASTM D3498.
EXCEPTION:
Sealants or adhesives need not be provided where a fire-resistance-rated assembly does not include them as a required component.
NEW SECTION
WAC 51-50-0718Section 718—Concealed spaces.
718.2.1 Fireblocking materials.Fireblocking shall consist of the following materials:
1. Two inch (51 mm) nominal lumber.
2. Two thicknesses of 1 inch (25 mm) nominal lumber with broken lap joints.
3. One thickness of 0.719 inch (18.3 mm) wood structural panels with joints backed by 0.719 inch (18.3 mm) wood structural panels.
4. One thickness of 0.75 inch (19.1 mm) particleboard with joints backed by 0.75 inch (19 mm) particleboard.
5. One half inch (12.7 mm) gypsum board.
6. One fourth inch (6.4 mm) cement-based millboard.
7. Batts or blankets of mineral wool, mineral fiber or other approved materials installed in such a manner as to be securely retained in place.
8. Cellulose insulation installed as tested for the specific application.
9. Mass timber complying with Section 2304.11.
NEW SECTION
WAC 51-50-0722Section 722—Calculated fire resistance.
722.7 Fire-resistance rating of mass timber. The required fire resistance of mass timber elements in Section 602.4 shall be determined in accordance with Section 703.2 or 703.3. The fire-resistance rating of building elements shall be as required in Tables 601 and 602 and as specified elsewhere in this code. The fire-resistance rating of the mass timber elements shall consist of the fire resistance of the unprotected element added to the protection time of the noncombustible protection.
722.7.1 Minimum required protection. When required by Sections 602.4.1 through 602.4.3, noncombustible protection shall be provided for mass timber building elements in accordance with Table 722.7.1(1). The rating, in minutes, contributed by the noncombustible protection of mass timber building elements, components, or assemblies, shall be established in accordance with Section 703.8. The protection contributions indicated in Table 722.7.1(2) shall be deemed to comply with this requirement when installed and fastened in accordance with Section 722.7.2.
Table 722.7.1(1)
Protection Required from Noncombustible Covering Material
Required Fire-Resistance Rating of Building Element per Tables 601 and 602 (hours)
Minimum Protection Required from Noncombustible Protection (minutes)
1
40
2
80
3 or more
120
Table 722.7.1(2)
Protection Provided by Noncombustible Covering Material
Noncombustible Protection
Protection Contribution (minutes)
1/2 inch Type X Gypsum board
25
5/8 inch Type X Gypsum board
40
722.7.2 Installation of gypsum board noncombustible protection. Gypsum board complying with Table 722.7.1(2) shall be installed in accordance with this section.
722.7.2.1 Interior surfaces. Layers of Type X gypsum board serving as noncombustible protection for interior surfaces of wall and ceiling assemblies determined in accordance with Table 722.7.1(1) shall be installed in accordance with the following:
1. Each layer shall be attached with Type S drywall screws of sufficient length to penetrate the mass timber at least 1 inch when driven flush with the paper surface of the gypsum board.
EXCEPTION:
The third layer, where determined necessary by Section 722.7, shall be permitted to be attached with 1 inch #6 Type S drywall screws to furring channels in accordance with ASTM C645.
2. Screws for attaching the base layer shall be 12 inches on center in both directions.
3. Screws for each layer after the base layer shall be 12 inches on center in both directions and offset from the screws of the previous layers by 4 inches in both directions.
4. All panel edges of any layer shall be offset 18 inches from those of the previous layer.
5. All panel edges shall be attached with screws sized and offset as in items 1 through 4 above and placed at least 1 inch but not more than 2 inches from the panel edge.
6. All panels installed at wall-to-ceiling intersections shall be installed such that the ceiling panel(s) is installed first and the wall panel(s) is installed after the ceiling panel has been installed and is fitted tight to the ceiling panel. Where multiple layers are required, each layer shall repeat this process.
7. All panels installed at a wall-to-wall intersection shall be installed such that the panel(s) covering an exterior wall or a wall with a greater fire-resistance rating shall be installed first and the panel(s) covering the other wall shall be fitted tight to the panel covering the first wall. Where multiple layers are required, each layer shall repeat this process.
8. Panel edges of the face layer shall be taped and finished with joint compound. Fastener heads shall be covered with joint compound.
9. Panel edges protecting mass timber elements adjacent to unprotected mass timber elements in accordance with Section 602.4.2.2 shall be covered with 1 1/4 inch metal corner bead and finished with joint compound.
722.7.2.2 Exterior surfaces. Layers of Type X gypsum board serving as noncombustible protection for the outside of the exterior heavy timber walls determined in accordance with Table 722.7.1(a) shall be fastened 12 inches on center each way and 6 inches on center at all joints or ends. All panel edges shall be attached with fasteners located at least 1 inch but not more than 2 inches from the panel edge. Fasteners shall comply with one of the following:
1. Galvanized nails of minimum 12 gage with a 7/16 inch head of sufficient length to penetrate the mass timber a minimum of 1 inch.
2. Screws that comply with ASTM C1002 (Type S, Type W, or Type G) of sufficient length to penetrate the mass timber a minimum of 1 inch.
NEW SECTION
WAC 51-50-0803Section 803—Wall and ceiling finishes.
803.3 Heavy timber exemption. Exposed portions of building elements complying with the requirements for buildings of Type IV construction in Section 602.4 shall not be subject to interior finish requirements except in interior exit stairways, interior exit ramps, and exit passageways.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-1004Section 1004.
Table 1004.1.2, Maximum Floor Area Allowances
Table 1004.1.2
Maximum Floor Area Allowances Per Occupant
FUNCTION OF SPACE
OCCUPANT LOAD FACTORa
Accessory storage areas, mechanical equipment room
300 gross
Agricultural building
300 gross
Aircraft hangars
500 gross
Airport terminal
 
 
Baggage claim
20 gross
 
Baggage handling
300 gross
 
Concourse
100 gross
 
Waiting areas
15 gross
Assembly
 
 
Gaming floors (keno, slots, etc.)
11 gross
 
Exhibit gallery and museum
30 net
Assembly with fixed seats
See Section 1004.4
Assembly without fixed seats
 
 
Concentrated (chairs only - Not fixed)
7 net
 
Standing space
5 netb
 
Unconcentrated (tables and chairs)
15 net
Bowling centers, allow 5 persons for each lane including 15 feet of runway, and for additional areas
7 net
Business areas
100 gross
Courtrooms - Other than fixed seating areas
40 net
Day care
35 net
Dormitories
50 gross
Educational
 
 
Classroom area
20 net
 
Shops and other vocational room areas
50 net
Exercise rooms
50 gross
Group H-5 - Fabrication and manufacturing areas
200 gross
Industrial areas
100 gross
Institutional areas
 
 
Inpatient treatment areas
240 gross
 
Outpatient areas
100 gross
 
Sleeping areas
120 gross
Kitchens, commercial
200 gross
Library
 
 
Reading rooms
50 net
 
Stack area
100 gross
Locker rooms
50 gross
Mall buildings - Covered and open
See Section 402.8.2
Mercantile
60 gross
 
Storage, stock, shipping areas
300 gross
Parking garages
200 gross
Residential
200 gross
Skating rinks, swimming pools
 
 
Rink and pool
50 gross
 
Decks
15 gross
Stages and platforms
15 net
Warehouses
500 gross
For SI: 1 square foot = 0.0929 m2, 1 foot = 304.8 mm.
a
Floor area in square feet per occupant.
b
The occupant load factor for fixed guideway transit and passenger rail systems shall be 15 net in accordance with NFPA 130.
1004.2 Increased occupant load. The occupant load permitted in any building, or portion thereof, is permitted to be increased from that number established for the occupancies in Table 1004.1.2, provided that all other requirements of the code are also met based on such modified number and the occupant load does not exceed one occupant per 7 square feet (0.65 m2) of occupiable floor space. Where required by the building official, an approved aisle, seating or fixed equipment diagram substantiating any increase in occupant load shall be submitted. Where required by the building official, such diagram shall be posted. See WAC 170-295-0080 (1)(b) for day care licensed by the state of Washington.
NEW SECTION
WAC 51-50-1406Section 1406—Combustible materials on the exterior sides of exterior walls.
1406.3 Balconies and similar projections. Balconies and similar projections of combustible construction other than fire-retardant-treated wood shall be fire-resistance-rated where required by Table 601 for floor construction or shall be of Type IV construction in accordance with Section 602.4.4. The aggregate length of the projections shall not exceed 50 percent of the building's perimeter on each floor.
NEW SECTION
WAC 51-50-1604Section 1604—General design requirements.
Table 1604.5
Risk Category of Buildings and Other Structures
RISK CATEGORY
NATURE OF OCCUPANCY
I
Buildings and other structures that represent a low hazard to human life in the event of failure including, but not limited to:
 
 
• Agricultural facilities.
 
 
• Certain temporary facilities.
 
 
• Minor storage facilities.
II
Buildings and other structures except those listed in Risk Categories I, III, and IV.
III
Buildings and other structures that represent a substantial hazard to human life in the event of failure including, but not limited to:
 
 
• Buildings and other structures whose primary occupancy is public assembly with an occupant load greater than 300.
 
 
• Buildings and other structures containing Group E or Group I-4 occupancies with an occupant load greater than 250.
 
 
• Buildings and other structures containing educational occupancies for students above the 12th grade with an occupant load greater than 500.
 
 
• Group I-2 occupancies with an occupant load of 50 or more resident care recipients but not having surgery or emergency treatment facilities.
 
 
• Group I-3 occupancies.
 
 
• Any other occupancy with an occupant load greater than 5,000.a
 
 
• Power-generating stations, water treatment facilities for potable water, wastewater treatment facilities and other public utility facilities not included in Risk Category IV.
 
 
• Buildings and other structures not included in Risk Category IV containing quantities of toxic or explosive materials that:
 
 
 
Exceed maximum allowable quantities per control area as given in Table 307.1(1) or 307.1(2) or per outdoor control area in accordance with the International Fire Code; and
 
 
 
Are sufficient to pose a threat to the public if released.b
IV
Buildings and other structures designated as essential facilities including, but not limited to:
 
 
• Group I-2 occupancies having surgery or emergency treatment facilities.
 
 
• Fire, rescue, ambulance and police stations, and emergency vehicle garages.
 
 
• Designated earthquake, hurricane, or other emergency shelters.
 
 
• Designated emergency preparedness, communications and operations centers, and other facilities required for emergency response.
 
 
• Power-generating stations and other public utility facilities required as emergency backup facilities for Risk Category IV structures.
 
 
• Buildings and other structures containing quantities of highly toxic materials that:
 
 
 
Exceed maximum allowable quantities per control area as given in Table 307.1(2) or per outdoor control area in accordance with the International Fire Code; and
 
 
 
Are sufficient to pose a threat to the public if released.b
 
 
• Aviation control towers, air traffic control centers, and emergency aircraft hangars.
 
 
• Buildings and other structures having critical national defense functions.
 
 
• Water storage facilities and pump structures required to maintain water pressure for fire suppression.
a
For purposes of occupant load calculation, occupancies required by Table 1004.1.2 to use gross floor area calculations shall be permitted to use net floor areas to determine the total occupant load.
b
Where approved by the building official, the classification of buildings and other structures as Risk Category III or IV based on their quantities of toxic, highly toxic or explosive materials is permitted to be reduced to Risk Category II, provided it can be demonstrated by a hazard assessment in accordance with Section 1.5.3 of ASCE 7 that a release of the toxic, highly toxic or explosive materials is not sufficient to pose a threat to the public.
AMENDATORY SECTION(Amending WSR 10-03-097, filed 1/20/10, effective 7/1/10)
WAC 51-50-1613((Reserved.))Section 1613.5—Amendments to ASCE 7.
1613.5 Amendments to ASCE 7. The provisions of Section 1613.5 shall be permitted as an amendment to the relevant provisions of ASCE 7. The text of ASCE 7 shall be amended as indicated in Sections 1613.5.2 through 1613.5.4.
1613.5.1 Transfer of anchorage forces into diaphragm. Modify ASCE 7 Section 12.11.2.2.1 as follows:
12.11.2.2.1 Transfer of anchorage forces into diaphragm. Diaphragms shall be provided with continuous ties or struts between diaphragm chords to distribute these anchorage forces into the diaphragms. Diaphragm connections shall be positive, mechanical or welded. Added chords are permitted to be used to form subdiaphragms to transmit the anchorage forces to the main continuous cross-ties. The maximum length-to-width ratio of a wood, wood structural panel or untopped steel deck sheathed structural subdiaphragm that serves as part of the continuous tie system shall be 2.5 to 1. Connections and anchorages capable of resisting the prescribed forces shall be provided between the diaphragm and the attached components. Connections shall extend into the diaphragm a sufficient distance to develop the force transferred into the diaphragm.
1613.5.2 Increased structural height limit. Modify ASCE 7 Section 12.2.5.4 as follows:
12.2.5.4 Increased structural height limit for steel eccentrically braced frames, steel special concentrically braced frames, steel buckling-restrained braced frames, steel special plate shear walls, and special reinforced concrete shear walls. The limits on height, hn, in Table 12.2-1 are permitted to be increased from 160 ft (50 m) to 240 ft (75 m) for structures assigned to Seismic Design Categories D or E and from 100 ft (30 m) to 160 ft (50 m) for structures assigned to Seismic Design Category F, if all of the following are satisfied:
1. The structure shall not have an extreme torsional irregularity as defined in Table 12.3-1 (horizontal structural irregularity Type 1b).
2. The steel eccentrically braced frames, steel special concentrically braced frames, steel buckling-restrained braced frames, steel special plate shear walls or special reinforced concrete shear walls in any one plane shall resist no more than 60 percent of the total seismic forces in each direction, neglecting accidental torsional effects.
3. Where floor and roof diaphragms transfer forces from the vertical seismic force-resisting elements above the diaphragm to other vertical force-resisting elements below the diaphragm, these in-plane transfer forces shall be amplified by the over-strength factor, Ωo for the design of the diaphragm flexure, shear, and collectors.
4. The earthquake force demands in foundation mat slabs, grade beams, and pile caps supporting braced frames and/or walls arranged to form a shear-resisting core shall be amplified by 2 for shear and 1.5 for flexure.
5. The earthquake shear force demands in special reinforced concrete shear walls shall be amplified by the over-strength factor, Ωo.
1613.5.3 Analysis procedure selection. Modify ASCE 7 Section 12.6.1 and Table 12.6-1 as follows:
12.6.1 Analysis procedure. The structural analysis required by Chapter 12 shall consist of one of the types permitted in Table 12.6-1, based on the structure's seismic design category, structural system, dynamic properties, and regularity, or with the approval of the authority having jurisdiction, an alternative generally accepted procedure is permitted to be used. The analysis procedure selected shall be completed in accordance with the requirements of the corresponding section referenced in Table 12.6-1.
Table 12.6-1 Permitted Analytical Procedures
Seismic Design Category
Structural Characteristics
Equivalent Lateral Force Procedure, Section 12.8a
Modal Response Spectrum Analysis, Section 12.9a
Linear Seismic Response History Procedures, Chapter 16a
Nonlinear Seismic Response History Procedures, Chapter 16b
B, C
All structures
P
P
P
P
D, E, F
Risk Category I or II buildings not exceeding two stories above the base
P
P
P
P
 
Structures of light frame construction
P
P
P
P
 
Structures with no structural irregularities and not exceeding 160 ft in structural height
P
P
P
P
 
Structures exceeding 160 ft in structural height with no structural irregularities and with T <3.5Ts
P
P
P
P
 
Structures not exceeding 160 ft in structural height and having only horizontal irregularities of Type 2, 3, 4, or 5 in Table 12.3-1 or vertical irregularities of Type 4, 5a, or 5b in Table 12.3-2
P
P
P
P
 
Structures not exceeding 160 ft in structural height and having only horizontal irregularities of Type 2, 3, 4, or 5 in Table 12.3-1 or vertical irregularities of Type 4, 5a, or 5b in Table 12.3-2
P
P
P
P
 
All other structures ≤ 240 ft in height
NP
P
P
P
 
All structures > 240 ft in height
NP
NP
NP
Pc
a
P: Permitted; NP: Not Permitted; Ts= SD1/SDS.
b
When nonlinear response history procedure is used, one of the linear procedures shall also be performed.
c
Refer to Section 12.6.2 for additional requirements.
1613.5.4 Nonlinear response history procedure for buildings in excess of 240 ft (75 m) in height. Modify ASCE 7 Section 12.6.2 as follows:
In addition to any of the linear analysis procedures in Table 12.6-1, a nonlinear dynamic analysis in accordance with ASCE 7 Chapter 16 shall be performed, except that analysis shall be conducted for MCER ground motions. Acceptance criteria shall be compatible with providing not greater than a 10 percent, 5 percent or 2-1/2 percent risk of collapse for Risk Category II, III and IV structures, respectively. In addition, proportioning of the seismic force-resisting system shall incorporate a capacity-based approach that identifies the mechanism of nonlinear lateral displacement of the structure, those structural actions expected to yield, and those intended to remain elastic. Design shall be subject to an approved independent structural design review.
NEW SECTION [AMENDATORY SECTION (Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)]
WAC 51-50-1705Section 1705—Required special inspections and tests.
1705.5.3 Mass timber construction.Special inspections of mass timber construction in buildings, structures, or portions thereof greater than 85 feet above grade plane shall be in accordance with Table 1705.5.3.
Table 1705.5.3
Required Special Inspections of Mass Timber Construction
Type
Continuous Special Inspection
Periodic Special Inspection
1. Inspection of anchorage and connections of mass timber construction to timber deep foundation systems.
 
X
2. Inspect erection and sequence of mass timber construction.
 
X
3. Inspection of connections where installation methods are required to meet design loads.
 
 
 
a. Threaded fasteners.
 
 
 
 
1. Verify use of proper installation equipment.
 
X
 
 
2. Verify use of predrilled holes where required.
 
X
 
 
3. Inspect screws, including diameter, length, head type, spacing, installation angle, and depth.
 
X
 
b. Adhesive anchors installed in horizontal or upwardly inclined orientation to resist sustained tension loads.
X
 
 
c. Bolted connections.
 
X
 
d. Other proprietary concealed connection.
 
X
1705.11.1 Structural wood.Continuous special inspection is required during field gluing operations of elements of the main windforce-resisting system. Periodic special inspection is required for nailing, bolting, anchoring and other fastening of elements of the main windforce-resisting system, including wood shear walls, wood diaphragms, drag struts, braces and hold-downs.
EXCEPTION:
Special inspections are not required for wood shear walls, shear panels and diaphragms, including nailing, bolting, anchoring and other fastening to other elements of the main windforce-resisting system, where the lateral resistance is provided by sheathing of wood structural panels, and the fastener spacing of the sheathing is more than 4 inches (102 mm) on center.
1705.12.2 Structural wood. For the seismic force-resisting systems of structures assigned to Seismic Design Category C, D, E, or F:
1. Continuous special inspection shall be required during field gluing operations of elements of the seismic force-resisting system.
2. Periodic special inspection shall be required for nailing, bolting, anchoring and other fastening of elements of the seismic force-resisting system, including wood shear walls, wood diaphragms, drag struts, braces, shear panels and hold-downs.
EXCEPTION:
Special inspections are not required for wood shear walls, shear panels and diaphragms, including nailing, bolting, anchoring and other fastening to other elements of the seismic force-resisting system, where the lateral resistance is provided by sheathing of wood structural panels, and the fastener spacing of the sheathing is more than 4 inches (102 mm) on center.
1705.19 Sealing of mass timber. Periodic special inspections of sealants or adhesives shall be conducted where sealant or adhesive required by Section 703.9 is applied to mass timber building elements as designated in the approved construction documents.
Reviser's note: The bracketed material preceding the section above was supplied by the code reviser's office.
NEW SECTION
WAC 51-50-2303Section 2303—Minimum standards and quality.
2303.1.4 Structural glued cross-laminated timber. Cross-laminated timbers shall be manufactured and identified in accordance with ANSI/APA PRG 320. Cross-laminated timbers in Construction Types IV-A, IV-B, and IV-C shall be manufactured and identified in accordance with ANSI/APA PRG 320 - 18.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-2900Chapter 29—Plumbing systems.
SECTION 2901—GENERAL.
2901.1 Scope. The provisions of this chapter and the state plumbing code shall govern the erection, installation, alteration, repairs, relocation, replacement, addition to, use or maintenance of plumbing equipment and systems. Toilet and bathing rooms shall be constructed in accordance with Section 1210. Plumbing systems and equipment shall be constructed, installed and maintained in accordance with the state plumbing code.
2901.2Health codes. In food preparation, serving and related storage areas, additional fixture requirements may be dictated by health codes.
SECTION 2902—MINIMUM PLUMBING FACILITIES.
2902.1 Minimum number of fixtures. Plumbing fixtures shall be provided in the minimum number shown in Table 2902.1. Uses not shown in Table 2902.1 shall be determined individually by the building official based on the occupancy which most nearly resembles the proposed occupancy. The number of occupants shall be determined by this code. Plumbing fixtures need not be provided for unoccupied buildings or facilities.
2902.1.1 Fixture calculations. To determine the occupant load of each sex, the total occupant load shall be divided in half. To determine the required number of fixtures, the fixture ratio or ratios for each fixture type shall be applied to the occupant load of each sex in accordance with Table 2902.1. Fractional numbers resulting from applying the fixture ratios of Table 2902.1 shall be rounded up to the next whole number. For calculations involving multiple occupancies, such fractional numbers for each occupancy shall first be summed and then rounded up to the next whole number.
EXCEPTION:
The total occupant load shall not be required to be divided in half where approved statistical data indicate a distribution of the sexes of other than 50 percent of each sex.
2902.1.1.1 Private offices. Fixtures only accessible to private offices shall not be counted to determine compliance with this section.
2902.1.1.2 Urinals. Where urinals are provided, one water closet less than the number specified may be provided for each urinal installed, except the number of water closets in such cases shall not be reduced to less than one quarter (25%) of the minimum specified. For men's facilities serving 26 or more persons, not less than one urinal shall be provided.
2902.1.2Family or assisted-use toilet and bath fixtures. Fixtures located within family or assisted-use toilet and bathing rooms required by Section 1109.2.1 are permitted to be included in the number of required fixtures for either the male or female occupants in assembly and mercantile occupancies.
2902.2Separate facilities. Where plumbing fixtures are required, separate facilities shall be provided for each sex.
EXCEPTIONS:
1. Separate facilities shall not be required for dwelling units and sleeping units.
 
2. Separate facilities shall not be required in structures or tenant spaces with a total occupant load, including both employees and customers, of 15 or less.
 
3. Separate facilities shall not be required in mercantile occupancies in which the maximum occupant load is 100 or less.
 
4. Separate facilities shall not be required in spaces primarily used for drinking or dining with a total occupant load, including both employees and customers, of 30 or fewer.
2902.2.1Family or assisted-use toilet facilities serving as separate facilities. Where a building or tenant space requires a separate toilet facility for each sex and each toilet facility is required to have only one water closet, two family or assisted-use toilet facilities shall be permitted to serve as the required separate facilities. Family or assisted-use toilet facilities shall not be required to be identified for exclusive use by either sex as required by Section 2902.4.
2902.3 Employee and public toilet facilities. Customers, patrons and visitors shall be provided with public toilet facilities in structures and tenant spaces intended for public utilization. The number of plumbing fixtures located within the required toilet facilities shall be provided in accordance with Section 2902.1 for all users. Employees shall be provided with toilet facilities in all occupancies. Employee toilet facilities shall either be separate or combined employee and public toilet facilities.
EXCEPTION:
Public toilet facilities shall not be required in:
 
1. Open or enclosed parking garages where there are no parking attendants.
 
2. Structures and tenant spaces intended for quick transactions, including takeout, pickup and drop-off, having a public access area less than or equal to 300 square feet (28 m2).
 
3. Fixed guideway transit and passenger rail systems constructed in accordance with Section 3112.
2902.3.1 Access. The route to the public toilet facilities required by Section 2902.3 shall not pass through kitchens, food preparation areas, unpackaged food storage areas, storage rooms or closets. Access to the required facilities shall be from within the building or from the exterior of the building. Access to toilets serving multiple tenants shall be through a common use area and not through an area controlled by a tenant. All routes shall comply with the accessibility requirements of this code. The public shall have access to the required toilet facilities at all times that the building is occupied. For other requirements for plumbing facilities, see Chapter 11.
2902.3.2 Location of toilet facilities in occupancies other than malls. In occupancies other than covered and open mall buildings, the required public and employee toilet facilities shall be located in each building not more than one story above or below the space required to be provided with toilet facilities, or conveniently in a building adjacent thereto on the same property, and the path of travel to such facilities shall not exceed a distance of 500 feet (152 m).
EXCEPTION:
The location and maximum distances of travel to required employee facilities in factory and industrial occupancies are permitted to exceed that required by this section, provided that the location and maximum distance of travel are approved.
2902.3.3 Location of toilet facilities in malls. In covered and open mall buildings, the required public and employee toilet facilities shall be located not more than one story above or below the space required to be provided with toilet facilities, and the path of travel to such facilities shall not exceed a distance of 300 feet (91,440 mm). In mall buildings, the required facilities shall be based on total square footage (m2) within a covered mall building or within the perimeter line of an open mall building, and facilities shall be installed in each individual store or in a central toilet area located in accordance with this section. The maximum distance of travel to central toilet facilities in mall buildings shall be measured from the main entrance of any store or tenant space. In mall buildings, where employees' toilet facilities are not provided in the individual store, the maximum distance of travel shall be measured from the employees' work area of the store or tenant space.
2902.3.4 Pay facilities. Where pay facilities are installed, such facilities shall be in excess of the required minimum facilities. Required facilities shall be free of charge.
2902.3.5 Door locking. Where a toilet room is provided for the use of multiple occupants, the egress door for the room shall not be lockable from the inside of the room. This section does not apply to family or assisted-use toilet rooms.
2902.3.6 Prohibited toilet room location. Toilet rooms shall not open directly into a room used for the preparation of food for service to the public.
2902.4 Signage. Required public facilities shall be provided with signs that designate the sex as required by Section 2902.2. Signs shall be readily visible and located near the entrance to each toilet facility. Signs for accessible toilet facilities shall comply with Section 1111.
2902.4.1 Directional signage. Directional signage indicating the route to the public toilet facilities shall be posted in a lobby, corridor, aisle or similar space, such that the sign can be readily seen from the main entrance to the building or tenant space.
2902.5 Drinking fountain location. Drinking fountains shall not be required to be located in individual tenant spaces provided that public drinking fountains are located within a distance of travel of 500 feet of the most remote location in the tenant space and not more than one story above or below the tenant space. Where the tenant space is in a covered or open mall, such distance shall not exceed 300 feet. Drinking fountains shall be located on an accessible route. Drinking fountains shall not be located in toilet rooms.
2902.5.1 Drinking fountain number. Occupant loads over 30 shall have one drinking fountain for the first 150 occupants, then one per each additional 500 occupants.
EXCEPTIONS:
1. Sporting facilities with concessions serving drinks shall have one drinking fountain for each 1000 occupants.
 
2. A drinking fountain need not be provided in a drinking or dining establishment.
2902.5.2 Multistory buildings. Drinking fountains shall be provided on each floor having more than 30 occupants in schools, dormitories, auditoriums, theaters, offices and public buildings.
2902.5.3 Penal institutions. Penal institutions shall have one drinking fountain on each cell block floor and one on each exercise floor.
2902.5.4 Bottle filling stations. Bottle filling stations shall be provided in accordance with Sections 2902.5.4.1 through 2902.5.4.3.
2902.5.4.1 Group E occupancies. In Group E occupancies with an occupant load over 30, a minimum of one bottle filling station shall be provided on each floor. This bottle filling station may be integral to a drinking fountain.
2902.5.4.2 Substitution. In all occupancies that require more than two drinking fountains per floor or secured area, bottle filling stations shall be permitted to be substituted for up to 50 percent of the required number of drinking fountains.
2902.5.4.3 Accessibility. At least one of the required bottle filling stations shall be located in accordance with Section 309 ICC A117.1.
2902.6 Dwelling units. Dwelling units shall be provided with a kitchen sink.
2902.7 Water closet space requirements. The water closet stool in all occupancies shall be located in a clear space not less than 30 inches (762 mm) in width, with a clear space in front of the stool of not less than 24 inches (610 mm).
2902.8 Water. Each required sink, lavatory, bathtub and shower stall shall be equipped with hot and cold running water necessary for its normal operation.
2902.9 Small occupancies. Drinking fountains shall not be required for an occupant load of 15 or fewer.
SECTION 2903—RESERVED.
SECTION 2904—RESERVED.
Table 2902.1
Minimum Number of Required Plumbing Fixturesa
(See Sections 2902.2 and 2902.3)
No.
Classification
Occupancy
Description
Water Closets
Lavatories
Bathtubs/
Showers
Male
Female
Male
Female
1
Assembly
A-1d
Theaters and other buildings for the performing arts and motion pictures
1 per 125
1 per 65
1 per 200
—
 
 
A-2d
Nightclubs, bars, taverns, dance halls and buildings for similar purposes
1 per 40
1 per 40
1 per 75
—
 
 
Restaurants, banquet halls and food courts
1 per 75
1 per 75
1 per 200
—
 
 
A-3d
Auditoriums without permanent seating, art galleries, exhibition halls, museums, lecture halls, libraries, arcades and gymnasiums
1 per 125
1 per 65
1 per 200
—
 
 
 
Passenger terminals and transportation facilities
1 per 500
1 per 500
1 per 750
—
 
 
 
Places of worship and other religious services
1 per 150
1 per 75
1 per 200
—
 
 
A-4
Coliseums, arenas, skating rinks, pools, and tennis courts for indoor sporting events and activities
1 per 75 for first 1,500 and 1 per 120 for remainder exceeding 1,500
1 per 40 for first 1,520 and 1 per 60 for remainder exceeding 1,520
1 per 200
1 per 150
—
 
 
A-5
Stadiums amusement parks, bleachers and grandstands for outdoor sporting events and activities
1 per 75 for first 1,500 and 1 per 120 for remainder exceeding 1,500
1 per 40 for first 1,520 and 1 per 60 for remainder exceeding 1,520
1 per 200
1 per 150
—
2
Business
B
Buildings for the transaction of business, professional services, other services involving merchandise, office buildings, banks, light industrial and similar uses
1 per 25 for first 50 and 1 per 50 for the remainder exceeding 50
1 per 40 for first 80 and 1 per 80 for remainder exceeding 80
—
3
Educational
Ee
Educational facilities
1 per 35
1 per 25
1 per 85
1 per 50
—
4
Factory and industrial
F-1 and F-2
Structures in which occupants are engaged in work fabricating, assembly or processing of products or materials
1 per 100
1 per 100
Check State (UPC)
5
Institutional
I-1
Residential care
1 per 10
1 per 10
1 per 8
 
 
I-2
Hospitals, ambulatory nursing home care recipientb
1 per roomc
1 per roomc
1 per 15
 
 
 
Employees, other than residential careb
1 per 25
1 per 35
—
 
 
 
Visitors other than residential care
1 per 75
1 per 100
—
 
 
I-3
Prisonsb
1 per cell
1 per cell
1 per 15
 
 
 
Reformatories, detention centers and correctional centersb
1 per 15
1 per 15
1 per 15
 
 
 
Employeesb
1 per 25
1 per 35
—
 
 
I-4
Adult day care and child day care
1 per 15
1 per 15
1
6
Mercantile
M
Retail stores, service stations, shops, salesrooms, markets and shopping centers
1 per 500
1 per 750
—
7
Residential
R-1
Hotels, motels, boarding houses (transient)
1 per sleeping unit
1 per sleeping unit
1 per sleeping unit
 
 
R-2
Dormitories, fraternities, sororities and boarding houses (not transient)
1 per 10
1 per 10
1 per 8
 
 
 
Apartment house
1 per dwelling unit
1 per dwelling unit
1 per dwelling unit
 
 
R-3
One- and two-family dwellings
1 per dwelling unit
1 per 10
1 per dwelling unit
 
 
 
Congregate living facilities with 16 or fewer persons
1 per 10
1 per 10
1 per 8
 
 
R-4
Congregate living facilities with 16 or fewer persons
1 per 10
1 per 10
1 per 8
8
Storage
S-1
S-2
Structures for the storage of goods, warehouses, storehouses and freight depots, low and moderate hazard
1 per 100
1 per 100
Check State (UPC)
a.
The fixtures shown are based on one fixture being the minimum required for the number of persons indicated or any fraction of the number of persons indicated. The number of occupants shall be determined by this code, except with respect to Group E occupancies the provisions of note "e" shall apply.
b.
Toilet facilities for employees shall be separate from facilities for inmates or care recipients.
c.
A single-occupant toilet room with one water closet and one lavatory serving not more than two adjacent patient sleeping units shall be permitted where such room is provided with direct access from each patient sleeping unit and with provisions for privacy.
d.
The occupant load for seasonal outdoor seating and entertainment areas shall be included when determining the minimum number of facilities required.
e.
For Group E occupancies: The number of occupants shall be determined by using a calculation of 100 square feet gross building area per student for the minimum number of plumbing fixtures.
NEW SECTION
WAC 51-50-3102Section 3102—Membrane structures.
3102.3 Type of construction. Noncombustible membrane structures shall be classified as Type II-B construction. Noncombustible frame or cable-supported structures covered by an approved membrane in accordance with Section 3102.3.1 shall be classified as Type II-B construction. Heavy timber frame-supported structures covered by an approved membrane in accordance with Section 3102.3.1 shall be classified as Type IV-HT construction. Other membrane structures shall be classified as Type V construction.
EXCEPTION:
Plastic less than 30 feet (9144 mm) above any floor used in greenhouses, where occupancy by the general public is not authorized, and for aquaculture pond covers is not required to meet the fire propagation performance criteria of Test Method 1 or 2, as appropriate, of NFPA 701.
3102.6.1.1 Membrane. A membrane meeting the fire propagation performance criteria of Test Method 1 or 2, as appropriate, of NFPA 701 shall be permitted to be used as the roof or as a skylight on buildings of Type II-B, III, IV-HT and V construction, provided that the membrane is not less than 20 feet (6096 mm) above any floor, balcony or gallery.
AMENDATORY SECTION(Amending WSR 16-03-064, filed 1/19/16, effective 7/1/16)
WAC 51-50-3500Chapter 35—((Reserved))Referenced standards.
Add the reference standards as follows:
Standard reference number
Title
Referenced in code section number
ANSI/APA PRG-320-18
Standard for Performance-Rated Cross-Laminated Timber (revised 2018)
602.4, 2303.1.4
NFPA 130
Standard for Fixed Guideway Transit and Passenger Rail Systems
3101.1, 3112
NEW SECTION
WAC 51-50-4700Appendix D.
D102.2.5 Structural fire rating. Walls, floors, roofs and their supporting structural members shall be not less than 1 hour fire-resistance-rated construction.
EXCEPTIONS:
1. Buildings of Type IV-HT construction.
 
2. Buildings equipped throughout with an automatic sprinkler system in accordance with Section 903.3.1.1.
 
3. Automobile parking structures.
 
4. Buildings surrounded on all sides by a permanently open space of not less than 30 feet (9144 mm).
 
5. Partitions complying with Section 603.1, Item 11.