According to the chapter 5.2 of the Dutch national application document NEN-EN 1995-1-1:2005/NB:2011 it is possible to take into account the spreading of the concentrated load. The spreading reduction factor can be estimated by the following expression:
The reduction factor limit values are 0 and 1.
If the wainscoting thickness is very big (the second moment of area I is also big) or/and the distance between the support a is very small, the expression will return the limit value to 0 – so the full spreading will appear and a very small spreading reduction factor (0.001) will be used in the software calculations.
If the wainscoting is very thin (so the second moment of area I is small) or/and the distance between the support a is very large, the expression will return the limit to the value 1 and the spreading procedure doesn't need to be applied.
The information about limit situations can be found in the tooltip in the last column of the Result tab grid.