Building Code Design Criteria
IRC 2000
§R301 Design
| Table R301.2(1) Climatic and Geographic Design Criteria |
||||||||
|---|---|---|---|---|---|---|---|---|
| Ground Snow Load | Wind | Seismic Design Categoryf,g | Subject to damage from | Winter design temp.f | Flood hazardsh | |||
| Speede (mph) | Weatheringa | Frost depth lineb | Termitec | Decayd | ||||
| 25 psf | 90 | B | 30" | 10°F | Zone C | |||
- Weathering may require a higher strength concrete or grade of masonry than necessary to satisfy the structural requirements of this code. The weathering column shall be filled in with the weathering index (i.e., "negligible," "moderate" or "severe") for concrete as determined from the Weathering Probability Map [Figure R301.2(3)]. 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.
- The frost line depth may require deeper footings than indicated in Figure R403.1(1). The jurisdiction shall fill in the frost line depth column with the minimum depth of footing below finish grade.
- The jurisdiction shall fill in this part of the table with "very heavy," "moderate to heavy," "slight to moderate," or "none to slight" in accordance with Figure R301.2(6) depending on whether there has been a history of local damage.
- The jurisdiction shall fill in this part ofthe table with "moderate to severe," "slight to moderate," or "none to slight" in accordance with Figure R301.2(7) depending on whether there has been a history of local damage.
- The jurisdiction shall fill in this part of the table with the wind speed from the basic wind speed map [Figure R301.2(4)]. Wind exposure category shall be determined on a site-specific basis in accordance with Section R301.2.1.4.
- The outdoor design dry-bulb temperature shall be selected from the columns of 97½-percent values for winter from Appendix D of the International Plumbing Code. Deviations from the Appendix Dtemperatures shall be permitted to reflect local climates or local weather experience as determined by the building official.
- The jurisdiction shall fill in this part of the table with the Seismic Design Category determined from Section R301.2.2.1.
- The jurisdiction shall fill in this part of the table with (a) the date of the jurisdiction's entry into the National Aood Insurance Program (date of adoption of the first code or ordinance for management of flood hazard areas), (b) the date(s) of the currently effective FIRM and FBFM, or other flood hazard map adopted by the community, as may be amended.
