Patio Cover Load Ratings
Some terms your building department may use include live load, ground snow load, roof design load, wind speed, wind exposure, seismic load, patio height, frost line, and property line setback. Note: Ground Snow Load and Roof Design Load differ; verify your snow rating when consulting your building department.
Live Loads and Snow Loads
Roof Design Load (RDL) is rated in pounds per square foot, and your region and elevation determine Live Load (LL) and Ground Snow Load (GSL).
Ground Snow Load is typically higher than the Roof Design Load, so verify what information the building dept. is giving you LL, GSL, or RDL.
Wind speed is measured in Miles Per Hour and exposure.
Exposure B: Urban and suburban areas, wooded areas, or other terrain with numerous closely spaced obstructions.
Exposure C: Open terrain with scattered obstructions.
Seismic Size Requirements (Ss) is the Maximum Considered Earthquake Ground Motion (0.2 sec).