How to Apply Fire Door Frame Mastic Without Losing Control of the Bead

Applying fire-rated mastic around a fire-door frame looks simple until the gap changes, the substrate is uneven and the material starts to spread where you do not want it. The first mistake is treating the job as a cosmetic caulking exercise. The frame-to-wall junction is part of the doorset installation, and the mastic arrangement has to match the particular installation evidence. BWF guidance says the specified intumescent material or mastic should be used for the particular installation and certificate information, and that the frame-to-wall detail should be checked before architrave is fitted. The Proudman diagnostic approach therefore starts with the junction itself, not with the easiest bead to lay. Start with the junction, not the cartridge Before the gun comes out, establish what you are actually sealing. Look at the frame material, the surrounding wall construction, the width and shape…