For a building located in a hurricane-prone region as defined in Section 202, or on any other building with a mean roof height exceeding that permitted by Table 1504.8 based on the exposure category and basic wind speed at the site, the following materials shall not be used on the roof:
MAXIMUM ALLOWABLE MEAN ROOF HEIGHT PERMITTED FOR BUILDINGS WITH AGGREGATE ON THE ROOF IN AREAS OUTSIDE A HURRICANE-PRONE REGION
|NOMINAL DESIGN WIND|
SPEED, Vasd (mph)b, d
|MAXIMUM MEAN ROOF HEIGHT (ft)a, c|
|Greater than 120||NP||NP||NP|
For SI:1 foot = 304.8 mm; 1 mile per hour = 0.447 m/s.
- Mean roof height as defined in ASCE 7.
- For intermediate values of Vasd, the height associated with the next higher value of Vasd shall be used, or direct interpolation is permitted.
- NP = gravel and stone not permitted for any roof height.
- Vasd shall be determined in accordance with Section 1609.3.1.
- An addition to a roof that supports living vegetation and includes a synthetic, high quality waterproof membrane, drainage layer, soil layer and light weight medium plants shall be permitted to comprise part or all of the roof area.
- Roof areas used as outdoor recreation space by the occupants of the building.
- An area including and adjacent to rooftop photovoltaic and solar thermal equipment, totaling not more than three times the area that is covered with such equipment.
- Limited roof areas as determined by regulations promulgated by the Department of Licenses and Inspections.
- A roof, the area of which is less than three (3) percent of the gross floor area of the building.