| Dead Load | Variable | Permanent loads due to the weight of the roof structure, materials, and any fixed equipment or installations on the roof. Common examples include roofing materials, insulation, and structural elements. |
| Live Load | Variable | Temporary loads due to human occupancy, maintenance activities, and equipment placement. Standards often dictate minimum live load requirements based on building type and usage. |
| Snow Load | Variable | Load imposed by accumulated snowfall on the roof surface. This varies significantly based on geographical location, climate, and local building codes. |
| Wind Load | Variable | Load exerted by wind pressure and suction on the roof. It depends on factors such as building height, shape, exposure, and local wind speeds. |
| Seismic Load | Variable | Load resulting from seismic activity. The magnitude of seismic loads depends on the building’s location, soil conditions, and local building codes. |
| Equipment Load | Variable | Additional loads imposed by mechanical equipment, HVAC systems, communication antennas, solar panels, or other rooftop installations. These loads vary based on the specific equipment and its placement. |
| Maintenance Load | Variable | Loads due to human activity during maintenance, repair, or inspection of the roof system. This includes foot traffic, equipment placement, and materials stored temporarily during maintenance work. |