306.5 Equipment and appliances on roofs or elevated structures.
FGC § 306.5
Where equipment or appliances requiring access are located on an elevated structure or the roof of a building such that personnel will have to climb higher than 16 feet (4877 mm) above grade, roof, or floor level to access such equipment or appliances, an interior or exterior means of access shall be provided. Such access shall not require climbing over obstructions greater than 30 inches (762 mm) in height or walking on roofs having a slope greater than 4 units vertical in 12 units horizontal (33-percent slope). Such access to the roof or elevated structure and access from the roof or elevated structure to equipment requiring maintenance shall not require the use of portable ladders. Where access involves climbing over parapet walls, the height shall be measured to the top of the parapet wall. Permanent ladders installed to provide the required access shall comply with the following minimum design criteria: 1. The side railing shall extend above the parapet or roof edge not less than 30 inches (762 mm).
2.Ladders shall have rung spacing not to exceed 12 inches (304.8 mm) on center. The uppermost rung shall be not more than 24 inches (609.6 mm) below the upper edge of the roof hatch, roof or parapet, as applicable.
3.Ladders shall have a toe spacing not less than 7 inches (177.8 mm) deep.
4.There shall be not less than 18 inches (457.2 mm) between rails.
5.Rungs shall have a diameter not less than 0.75-inch (19 mm) and be capable of withstanding a 300-pound (136.1 kg) load.
6.Where a cage, well or ladder safety device is provided, ladders over 20 feet (6096 mm) in height shall be provided with landing platforms for each 30 feet (9144 mm) of height. Where a cage, well or ladder safety device is not provided, ladders over 20 feet (6096 mm) in height shall be provided with landing platforms for each 20 feet (6096 mm) in height. Landings shall be capable of withstanding a load of 100 pounds per square foot (488.2 kg/m 2 ). A guardrail and toeboard shall be provided on all open sides of the landing.
7.Climbing clearance. The distance from the centerline of the rungs to the nearest permanent object on the climbing side of the ladder shall be not less than 30 inches (762 mm) measured perpendicular to the rungs. This distance shall be maintained from the point of ladder access to the bottom of the roof hatch. A minimum clear width of 15 inches (381 mm) shall be provided on both sides of the ladder measured from the midpoint of and parallel with the rungs, except where cages or wells are installed.
8.Landing required. The ladder shall be provided with a clear and unobstructed bottom landing area having a minimum dimension of 30 inches by 30 inches (762 mm by 762 mm) centered in front of the ladder.
9.Ladders shall be protected against corrosion by approved means.
10.Service personnel shall have access to ladders at all times.
11.Where ladder extensions are installed, the side rails of through or side-step ladder extensions shall extend 3 1/2 feet (1066.8 mm) above the parapets and landings. For through ladder extensions, the rungs shall be omitted from the extensions and shall have not less than 18 inches (457.2 mm) nor more than 24 inches (609.6 mm) of clearance between rails. For side-step or offset fixed ladder sections, at landings, the side rails and rungs shall be carried to the next regular rung beyond or above the 3 1/2 feet (1066.8 mm) minimum. Catwalks installed to provide the required access shall be not less than 24 inches (609.6 mm) wide and shall have railings as required for service platforms. Exception: This section shall not apply to Group R-3 occupancies.
