Table of Design Wind Pressures
Element | Wind zone II design wind speed 100 MPH | Wind zone III design wind speed 110 MPH |
Anchorage for lateral and vertical stability (See § 3280.306(a) ): | ||
Net Horizontal Drag1 2: | 3±39 PSF | 3±47 PSF |
Uplift4: | 5 -27 PSF | -32 PSF |
Main wind force resisting system: | ||
Shearwalls, Diaphragms and their Fastening and Anchorage Systems1 2 | ±39 PSF | ±47 PSF |
Ridge beams and other Main Roof Support Beams (Beams supporting expanding room sections, etc.) | -30 PSF | -36 PSF |
Components and cladding: | ||
Roof trusses4 in all areas; trusses shall be doubled within 3'-0' from each end of the roof | 5 -39 PSF | 5 -47 PSF |
Exterior roof coverings, sheathing and fastenings4,6,7 in all areas except the following | 5 -39 PSF | 5 -47 PSF |
Within 3'-0' from each gable end (overhang at end wall) of the roof or endwall if no overhang is provided4,6,7 | 5 -73 PSF | 5 -89 PSF |
Within 3'-0' from the ridge and eave (overhang at sidewall) or sidewall if no eave is provided4,6,7 | 5 -51 PSF | 5 -62 PSF |
Eaves (Overhangs at Sidewalls)4,6,7 | 5 -51 PSF | 5 -62 PSF |
Gables (Overhangs at Endwalls)4,6,7 | 5 -73 PSF | 5 -89 PSF |
Wall studs in sidewalls and endwalls, exterior windows and sliding glass doors (glazing and framing), exterior coverings, sheathing and fastenings8: | ||
Within 3'-0' from each corner of the sidewall and endwall | ±48 PSF | ±58 PSF |
All other areas | ±38 PSF | ±46 PSF |
NOTES:
1 The net horizontal drag of ±39 PSF to be used in calculating Anchorage for Lateral and Vertical Stability and for the design of Main Wind Force Resisting Systems is based on a distribution of wind pressures of + 0.8 or + 24 PSF to the windward wall and -0.5 or -15 PSF to the leeward wall.
2 Horizontal drag pressures need not be applied to roof projections when the roof slope does not exceed 20 degrees.
3 + sign would mean pressures are acting towards or on the structure; - sign means pressures are acting away from the structure; ±sign means forces can act in either direction, towards or away from the structure.
4 Design values in this "Table" are only applicable to roof slopes between 10 degrees (nominal 2/12 slope) and 30 degrees.
5 The design uplift pressures are the same whether they are applied normal to the surface of the roof or to the horizontal projection of the roof.
6 Shingle roof coverings that are secured with 6 fasteners per shingle through an underlayment which is cemented to a 3/8" structural rated roof sheathing need not be evaluated for these design wind pressures.
7 Structural rated roof sheathing that is at least 3/8" in thickness, installed with the long dimension perpendicular to roof framing supports, and secured with fasteners at 4" on center within 3'-0' of each gable end or endwall if no overhang is provided and 6" on center in all other areas, need not be evaluated for these design wind pressures.
8 Exterior coverings that are secured at 6" o.c. to a 3/8" structural rated sheathing that is fastened to wall framing members at 6" on center need not be evaluated for these design wind pressures.
Local governments: The following local governments listed by State (counties, unless specified otherwise):
Alabama: Baldwin and Mobile.
Florida: All counties except those identified in paragraph (c)(1)(i)(C) of this section as within Wind Zone III.
Georgia: Bryan, Camden, Chatham, Glynn, Liberty, McIntosh.
Louisiana: Parishes of Acadia, Allen, Ascension, Assumption, Calcasieu, Cameron, East Baton Rouge, East Feliciana, Evangeline, Iberia, Iberville, Jefferson Davis, LaFayette, Livingston, Pointe Coupee, St. Helena, St. James, St. John the Baptist, St. Landry, St. Martin, St. Tammany, Tangipahoa, Vermillion, Washington, West Baton Rouge, and West Feliciana.
Maine: Hancock and Washington.
Massachusetts: Barnstable, Bristol, Dukes, Nantucket, and Plymouth.
Mississippi: George, Hancock, Harrison, Jackson, Pearl River, and Stone.
North Carolina: Beaufort, Brunswick, Camden, Chowan, Columbus, Craven, Currituck, Jones, New Hanover, Onslow, Pamlico, Pasquotank, Pender, Perquimans, Tyrrell, and Washington.
South Carolina: Beaufort, Berkeley, Charleston, Colleton, Dorchester, Georgetown, Horry, Jasper, and Williamsburg.
Texas: Aransas, Brazoria, Calhoun, Cameron, Chambers, Galveston, Jefferson, Kenedy, Kleberg, Matagorda, Nueces, Orange, Refugio, San Patricio, and Willacy.
Virginia: Cities of Chesapeake, Norfolk, Portsmouth, Princess Anne, and Virginia Beach.
Florida: Broward, Charlotte, Collier, Dade, Franklin, Gulf, Hendry, Lee, Martin, Manatee, Monroe, Palm Beach, Pinellas, and Sarasota.
Louisiana: Parishes of Jefferson, La Fourche, Orleans, Plaquemines, St. Bernard, St. Charles, St. Mary, and Terrabonne.
North Carolina: Carteret, Dare, and Hyde.
Zone (see Map in § 3280.305(c)(4) ) | Pounds per square foot |
North Zone | 40 |
Middle Zone | 30 |
South Zone | 20 |
Maine-Aroostook, Piscataquis, Somerset, Penobscot, Waldo, Knox, Hancock, and Washington.
Alaska-All Counties
States | Counties | |||
South Dakota | Grant | Brookings | Hanson | Lincoln |
Codington | Miner | Minnehaha | Yankton | |
Deuel | Lake | Hutchinson | Union | |
Hamlin | Moody | Turner | Clay | |
Kingsbury | McCook | |||
Minnesota | Koochiching | Stearns | Renville | Sibley |
Itasca | Swift | McLeod | Nicollet | |
Hubbard | Kandiyohi | Carver | Blue Earth | |
Cass | Meeker | Dakota | Martin | |
Crow Wing | Wright | Goodhue | Watonwan | |
Aitkin | Lac qui Parle | Wabasha | Brown | |
St. Louis | Chippewa | Winona | Redwood | |
Lake | Yellow Medicine | Fillmore | Lyon | |
Cook | Mille Lacs | Mower | Lincoln | |
Carlton | Kanabec | Olmsted | Pipestone | |
Pine | Benton | Dodge | Murray | |
Wadena | Isanti | Rice | Cottonwood | |
Todd | Sherburne | Steele | Jackson | |
Morrison | Anoka | Freeborn | Nobles | |
Douglas | Chisapo | Faribault | Rock | |
Grant | Washington | Waseca | ||
Stevens | Hennepin | Le Sueur | ||
Pope | Ramsey | Scott | ||
Iowa | Hancock | Mitchell | Hamilton | Buena Vista |
Lyon | Howard | Webster | Cherokee | |
Osceola | Chickasaw | Calhoun | Plymouth | |
Dickinson | Butler | Sac | Sioux | |
Emmet | Floyd | Ida | O'Brien | |
Kossuth | Cerro Gordo | Humboldt | Clay | |
Winnebago | Franklin | Pocahontas | Wright | |
Worth | Hardin | Palo Alto | ||
Wisconsin | Douglas | Oconto | Pepin | Lincoln |
Bayfield | Menominee | Pierce | Oneida | |
Ashland | Langlade | Dunn | Polk | |
Iron | Marathon | Eau Claire | Burnett | |
Vilas | Clark | Chippewa | Washburn | |
Forest | Jackson | Rusk | Sawyer | |
Florence | Trempealeau | Barron | Price | |
Marinette | Buffalo | Taylor | Door | |
St. Croix | ||||
Michigan | Houghton | Iron | Presque Isle | Wexford |
Baraga | Dickinson | Charlevoix | Benzie | |
Marquette | Menominee | Montmorency | Grand Traverse | |
Alger | Delta | Alpena | Kalkaska | |
Luce | Schoolcraft | Alcona | Oscoda | |
Chippewa | Mackinac | Ogemaw | Otsego | |
Keweenaw | Cheyboygan | Roscommon | Leelanau | |
Ontonagon | Emmet | Missaukee | Antrim | |
Gogebic | Crawford | |||
New York | St. Lawrence | Herkimer | Onondaga | Genesee |
Franklin | Lewis | Madison | Orleans | |
Clinton | Oswego | Cayuga | Niagara | |
Essex | Jefferson | Seneca | Erie | |
Hamilton | Oneida | Wayne | Wyoming | |
Warren | Fulton | Ontario | Monroe | |
Saratoga | Montgomery | Yates | ||
Washington | Schenectady | Livingston | ||
Massachusetts | Essex | |||
Maine | Franklin | Kennebec | Lincoln | Cumberland |
Oxford | Androscoggin | Sagadahoc | York | |
Montana | All Counties | |||
Idaho | All Counties | |||
Colorado | All Counties | |||
Wyoming | All Counties | |||
Utah | All Counties | |||
Vermont | Franklin | Orleans | Caledonia | Addison |
Grand Isle | Essex | Washington | Rutland | |
Lamoille | Chittenden | Orange | Windsor | |
New Hampshire | All Counties |
Floor-L/240
Roof and ceiling-L/180
Headers, beams, and girders (vertical load)-L/180
Walls and partitions-L/180
24 C.F.R. §3280.305