17th May 2022 What variations to the plasterboard facing are allowed? The proposed construction shall be a steel stud plasterboard lined wall than includes an Intrim Mouldings FR MDF skirting board backed with 50mm CRS Fibretex 350 Rockwool insulation as tested in FSP 1997 and subject to the following variations: The wall linings may vary to include other proprietary brands and 16mm Fire grade plasterboard provided they have been tested or assessed to be fixed to each side of a 64mm steel stud without cavity insulation and achieve an FRL of at least 60-60. The plasterboard used in this test was 16mm CSR Fyrcheck plasterboard. The wall may increase in height. If the wall increases in thickness the maximum difference between the insulation thickness and the cavity size shall be as tested 14mm.