A board’s rating describes a tested system, not a sheet of material. The fixings, the joints, and the penetrations decide whether it performs.
A fire-rated board does not carry a rating on its own. The rating belongs to a tested system — the board, its fixings, its joints, and the substrate behind it. Change the system and the rating no longer applies.
Inspectors check three things first: fixing centres, joint treatment, and how penetrations through the board are sealed. A correctly rated board with the wrong fixings fails as surely as the wrong board.
We specify the board as a system and document each of those three details before close-up. The rating then describes what was actually built.
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