ABSTRACT
In the United States, roof design snow load values are based upon codes and standards. These codes and standards normally utilize a 50-year mean recurrence interval to determine acceptable snow loads. This means that there is only a 2% statistical chance that the code-based design snow load will be exceeded within the 50-year time frame. These design snow loads are therefore on the more extreme end of the scale for a given locality in order to protect the health, safety and welfare of the project and its occupants. However, complex roofs can develop snow loads beyond code limits.
