Opening the Snow/Wind Load dialog and clicking the Snow tab displays the following dialog.
The following options are at the top of the dialog:
- Ground snow load Pg - Specifies the ground snow load.
- Thermal factor Ct - Specifies a thermal factor value.
- Roof slope factor Cs is assumed depending on the roof slope. The value of this factor depends of the roof type (warm roof or cold roof). The options: Unobstructed slippery surface, Ventilated roof and Thermal resistance R affect the definition of a curve (dashed or continuous) that determines the Cs factor, according to the guidelines in points 7.4.1 and 7.4.2 ASCE 7-16.
The Exposure factor Ce field has the following options:
- Automatic - Automatically calculates a snow load based on the specified parameters: terrain category and roof exposure condition.
- Manual - Lets you manually specify an exposure factor.
- In the Snow gathering field, the Unbalanced Snow Loads option generates a snow load that considers snow sliding off a sloped roof, snow drifts as well as snow gathered by different roof projections (gutters and acroterions). By default, snow loads are generated that account for unbalanced snow loads on roofs.
Clicking Coefficient opens the dialog for specifying the coefficients for a snow load.