While we are on the subject, I have question.... I have a second floor porch I intend to enclose in order to add a room. What would become the interior walls are now covered with Hardie Plank lapped siding. Should I remove the siding or can I just sheetrock over the stuff after enclosing the porch? Should I fill in the lap grooves with plaster or such before installing the drywall, if it can be sheetrocked over?

Any advice appreciated!
Thanks!