DON'T EVEN THINK ABOUT TAKING THE TILES OFF,years ago they only had tiles on the roof,the loft got filled with muck and soot blown in from under the tiles,the felt stops this and allows condensation to evaporate out of the roof.I suspect it won't be much so it won't cause a problem,tape it up with gaffa tape or wedge some thin battens across the rafters,don't go to the expense of having tiles removed.
Rich, November 2009