Can I declare child row types for table already populated from server code?

LesF

I am applying the DataTable type to a table that was already populated in server code, but every odd numbered row is a parent row which is followed by a child row with one td spanning the whole table width.
I cannot find a way to declare which is a parent and which is a child row, so when the DataTable type is applied it throws:
Error: Unable to set property '_DT_CellIndex' of undefined or null reference

Is there a way to declare the child rows in markup, e.g. a class name? or do I have to re-write the entire table population process to use DataTable methods?

example