Sorry, but colspan and rowspan are great in table-cells but not available in Mendix Datagrids. Each column will always take up one column and each object will always take up one row.

All that is available is setting the width of a column.

Having said that, it is not a rowspan but there is a way to set the height of a row, the 3-rd row in this example:

• assign a class to your datagrid, say ‘mygrid’
• in custom.scss add

  .mygrid{
    tr:nth-of-type(3){
      height: 300px;
    }
  }