Patio covers. One-story structures not exceeding 12 feet (3657 mm) in height. Enclosure walls shall be permitted to be of any configuration, provided the open or glazed area of the longer wall and one additional wall is equal to at least 65 percent of the area below a minimum of 6 feet 8 inches (2032 mm) of each wall, measured from the floor. Openings shall be permitted to be enclosed with (1) insect screening, (2) approved translucent or transparent plastic not more than 0.125 inch (3.2 mm) in thickness, (3) glass conforming to the provisions of Section R308, or (4) any combination of the foregoing.
TABLE AH107.4(1) DESIGN WIND PRESSURES FOR ALUMINUM SCREEN ENCLOSURE FRAMING WITH AN IMPORTANCE FACTOR OF 0.77a, b, c
|LOAD CASE||WALL||Basic Wind Speed (mph)|
|Exposure Category Design Pressure (psf)|
|Ad||Windward and leeward walls (flow thru) and windward wall (non-flow thru) L/W = 0-1||12||8||14||10||17||12||19||14||23||16||26||18|
|Ad||Windward and leeward walls (flow thru) and windward wall (non-flow thru) L/W = 2||13||9||16||11||19||14||22||16||26||18||30||21|
|Be||Windward: Non-gable roof||16||12||20||14||24||17||28||20||32||23||37||26|
|Be||Windward: Gable roof||22||16||27||19||32||23||38||27||44||31||50||36|
a. Values have been reduced for 0.77 Importance Factor in accordance with Table 1604.5 of the Building Code of New York State.
b. Minimum design pressure shall be 10 psf in accordance with Section 1609.1.2 of the Building Code of New York Statee.
c. Loads are applicable to screen enclosures with a mean roof height of 30 feet or less. For screen enclosures of different heights the pressures given shall be adjusted by multiplying the table pressure by the adjustment factor given in Table AH107.4(2).
d. For Load Case A flow thru condition the pressure given shall be applied simultaneously to both the upwind and downwind screen walls acting in the same direction as the wind. The structure shall also be analyzed for wind coming from the opposite direction. For the non-flow thru condition the screen enclosure wall shall be analyzed for the load applied acting toward the interior of the enclosure.
e. For Load Case B the table pressure multiplied by the projected frontal area of the screen enclosure is the total drag force, including drag on screen surfaces parallel to the wind, which must be transmitted to the ground. Use Load Case A for members directly supporting the screen surface perpendicular to the wind. Load Case B loads shall be applied only to structural members which carry wind loads from more than one surface.
f. The roof structure shall be analyzed for the pressure given occurring both upward and downward.
TABLE AH107.4(2) HEIGHT ADJUSTMENT FACTORS
|Roof Height (ft)||B||C|