What happened
A south London loft conversion reached second fix. Plasterboard fitted, mist coat on. The independent inspector flagged that standard plasterboard had been used on the ceiling above the protected stair, not fire-rated board.
How it was discovered
Cross-checked the product on site against the approved specification. The delivery note confirmed it was 12.5mm wallboard, not 15mm Type F fire board.
The consequences
Strip out, replace board, redo skim and decoration. Three weeks delay. Genuine cost — but a Completion Certificate at the end, rather than a problem at resale.
What homeowners can learn
What gets installed matters more than what gets specified. Check before it is covered up.