Hanging Tiles - Insulation

Hi, My question is very basic, which tradesmen would be best for this job? I'm put this is the roofers category as it seems like its the same skills as roofing... I have approx 40m2 of hanging tiles on the 1st floor my house, they are hung on battens attached to single block work walls. I'd like to have the tiles and battens removed, Celotex (or similar) insulation attached to the blockwork and then the battens, tiles re-attached.