If the distance to the short side is greater than "Max distance to shortside", the value defined with this variable will add an overlapping girder that will be placed to reinforce.

The setting "Use support overlap girders" needs to be set to yes for this variable to be active. The setting can be set in Project Manager as well as in Standard Admin.

In this case the criteria for the lattice girders are set as following where no extra overlap girder will be placed if the distance is between 11 and 30 to the short side. 

The length interval is set to 200 mm.

Example of the IMPACT default setting:

Example with a user default setting: