Permeability

Opening the Snow/Wind Load dialog and clicking the Permeability tab displays the following dialog.

The dialog defines the permeability of structure walls. Wall permeability has a direct effect on generating the coefficients of wind pressure inside a structure. When you select an option its diagram displays in the upper-right corner of the dialog.

The dialog box is divided into 2 fields with certain option groups:

Note: Permeability is always expressed in %. For a completely open wall, the permeability value is 100%; whereas, for a completely closed wall it is 0%.