It depends on which product and system is being used. We offer a choice of two systems depending on requirements, firstly the FireCase system which uses the Glasroc F FIRECASE board to form a frameless encasement around the beam or column, and secondly the GypLyner ENCASE system which uses Gyproc FireLine plasterboard mounted on a Gypframe metal framework.
With the FireCase system the space used could be as little as 15mm which is the Glasroc F FIRECASE board itself. The GypLyner ENCASE system requires more space due to the metal framework between the plasterboards and the steel section. Please refer to WHITE BOOK Chapter 03 Section 02 Page 02 or Chapter 03 Section 03 Page 02 for more details, including layout drawings.