HomeMy WebLinkAboutClimatic design criteria IRC 2016 TABLE R301City Amendments to IRC Table R301.2(1), Climatic and Geographic Design Criteria: Table R301.2(1) of the International Residential
Code is amended to read as follows:
Footnotes:
1. When using this roof snow load it will be left to the engineer’s judgment whether to consider drift or sliding snow.
However, rain on snow surcharge of five (5) psf must be considered for roof slopes less than five degrees (5°).
2. Wind exposure category and Topographic effects (Wind Speed-up Kzt factor) shall be determined on a site-specific basis
by the Design Professional in Responsible Charge (components and cladding need not consider topographic effects unless otherwise
determined by the engineer of record).
3. From IRC Table 301.2(1).
4. 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.
5. The City of Renton participates in the National Flood Insurance Program (NFIP) as specified in City of Renton Resolution
No. 1984, dated April 21, 1975. The City’s Flood Insurance Study is April 19, 2005, and the number and date of current effective
Flood Insurance Rate Maps (FIRMS) are as follows:
53033CIND0A 04/19/2005
53033C0664F 05/16/1995
53033C0666F 05/16/1995
53033C0668F 05/16/1995
53033C0669F 05/16/1995
IRC Table R301.2(1)
Climatic and Geographic Design Criteria
Roof
Snow
Load1
Wind Design2 Seismic
Design
Category
3
Subject to Damage From: Outside
Design
Temp. –
Heat/Cool
Ice
Barrier
Under-
layment
Required
Flood
Hazards5
Air
Freezing
Index
Mean
Annual
Temp. Speed
Topo-
graphic
Effects
Weathering
4
Frost
Line
Depth
Termite
Decay
25 psf 110
mph
See
footnote
2
D2 Moderate 12" Slight to
Moderate
24ºF/83ºF No N/A 113 50ºF
53033C0957F 05/16/1995
53033C0976F 05/16/1995
53033C0977F 05/16/1995
53033C0978F 05/16/1995
53033C0979F 05/16/1995
53033C0981F 05/16/1995
53033C0982F 05/16/1995
53033C0983F 05/16/1995
53033C0984F 05/16/1995
53033C0986F 05/16/1995
53033C0987F 05/16/1995