We are completing metal stair and landing rails for the main fire-protected stairwell of a small block of 8 new apartments. We need to specify a 30-minute fireproof undercoat. What products do you suggest, as most of your fire-retardant metal coatings are for structural steelwork? Ditto black topcoats: Hammerite instantly springs to mind, but anything else? With thanks in advance . . .