Chapter 21.10
INTERNATIONAL RESIDENTIAL CODE
Sections:
21.10.010 International Residential Code adopted.
21.10.013 Copies on file.
21.10.016 Administration.
21.10.020 IRC Table R301.2(1) amended.
21.10.025 IRC 311.7.7, Stairway walking surface, amended.
21.10.010 International Residential Code adopted.
The 2018 Edition of the International Residential Code, as adopted by the State Building Code Council in Chapter 51-51 WAC, as published by the International Code Council, excluding Chapter 1, “Administration,” is adopted, together with the following amendments. The Construction Administrative Code, as set forth in Chapter 21.06, shall be used in place of IRC Chapter 1, Administration. (Ord. 4751 § 27, 2021; Ord. 4524 § 46, 2016: Ord. 4410 § 7, 2013: Ord. 4246 § 3 (part), 2010: Ord. 4099 § 4 (part), 2007: Ord. 3946 § 1 (part), 2004)
21.10.013 Copies on file.
The city shall at all times keep on file with the city clerk, for reference by the general public, not less than one copy of the International Residential Code. (Ord. 4246 § 3 (part), 2010: Ord. 4208 § 4 (part), 2009)
21.10.016 Administration.
The administrative provisions for the enforcement of the International Residential Code are located in Chapter 21.06. (Ord. 4246 § 3 (part), 2010: Ord. 4208 § 4 (part), 2009)
21.10.020 IRC Table R301.2(1) amended.
IRC Table R301.2(1) is amended to read:
|
ROOF SNOW LOADa (psf) |
WIND DESIGN |
SEISMIC DESIGN CATEGORY |
SUBJECT TO DAMAGE FROM |
OUTDOOR DESIGN TEMP (F) - Heat/ Cool |
ICE BARRIER UNDERLAYMENT REQUIRED |
FLOOD HAZARDe |
AIR FREEZING INDEX |
MEAN ANNUAL TEMP |
|||||
|
Speedb (mph) |
Topographic effectsc |
Special wind region |
Windborne debris zone |
Weatheringd |
Frost line depth |
Termite |
|||||||
|
25 |
110 |
Yes |
No |
No |
D2 |
Moderate |
12” |
Slight to Moderate |
83/17 |
No |
N.A. |
113 |
53 |
|
MANUAL J DESIGN CRITERIA |
|||||||||||||
|
Elevation |
Latitude |
Winter heating |
Summer cooling |
Altitude correction factor |
Indoor design temperature |
Design temperature cooling |
Heating temperature difference |
||||||
|
154 feet |
47o39’26’’ |
72oF max |
75oF min |
0.99 |
72oF |
75oF |
45oF |
||||||
|
Cooling temperature difference |
Wind velocity heating |
Wind velocity cooling |
Coincident wet bulb |
Daily range |
Winter humidity |
Summer humidity |
|
||||||
|
8oF |
N.A. |
N.A. |
66 |
Medium |
75% |
68% |
|
||||||
a. This is the minimum roof snow load. When using this snow load it will be left to the engineer’s judgment whether to consider drift or sliding snow. However, rain on snow surcharge of 5 psf must be considered for roof slopes less than 5 degrees.
b. Wind exposure category and Topographic effects (Wind Speed-up Kzt factor) shall be determined on a site-specific basis by the Engineer of Record (components and cladding need not consider topographic effects unless otherwise determined by the engineer of record).
c. Weathering may require a higher strength concrete or grade of masonry than necessary to satisfy the structural requirements of this code. The grade of masonry units shall be determined from ASTM C 34, C 55, C 62, C 73, C 90, C 129, C 145, C 216 or C 652.
d. The City of Kirkland participates in the National Flood Insurance Program (NFIP); Regular Program (No Special Flood Hazard Area).
(Ord. 4751 § 28, 2021; Ord. 4524 § 47, 2016: Ord. 4410 § 8, 2013: Ord. 4246 § 3 (part), 2010: Ord. 4099 § 4 (part), 2007)
21.10.025 IRC 311.7.7, Stairway walking surface, amended.
Section 311.7.7 of the IRC is amended to read:
The walking surface of treads and landings of stairways shall be sloped not steeper than one-unit vertical in 48 inches horizontal (2-percent slope). Stairway treads and landings shall have a solid surface.
(Ord. 4751 § 29, 2021)