To change either the material or thickness of a surface region, use the following procedure.

1. Select the surface regions that will have the same properties.
2. To change the material for the surface regions:
   1. On the Region ribbon tab, select the Material tool in the Properties group.
      
      The Assign material dialog opens.
   2. Select the Source for the material definition.
      • Catalog - Used to select one of the included STAAD.Pro material definitions.
      • Model - Used to select catalog materials previously added to your current model.
      • User Database - Used to select custom materials previously saved in your user database.
   3. Select the material you want to use from the following dialog controls.
      Note: For Catalog materials, you must select the Type, Country, and Material Type first. Similarly, for User Database, you must select the Type and Material type first.
   4. Click OK.
   The dialog closes and the material selections are assigned to the selected surface regions.
3. To change the thickness for the surface region:
   1. On the Region ribbon tab, select the Thickness tool in the Properties group.
      
      The Assign Region Thickness dialog opens.
   2. Type a Thickness value.
   3. Click OK. The dialog closes and the thickness value is assigned to selected surface regions.
   4. (Optional) On the Region ribbon tab, select the Alignment tool option from the drop-down list in the Properties group. By default, surface regions are center aligned to the parent surface. You can align one face for surfaces with a different thickness (e.g., drop-panels or relief wall panels).