You may be wondering whether it’s acceptable to paint over the intumescent seals on your fire doors. Technically, the answer is yes—you can paint them—but it’s strongly discouraged. Intumescent seals are a critical component of a fire door’s performance. In the event of a fire, these seals are designed to expand when exposed to heat, effectively sealing the gap between the door and the frame to slow the spread of fire and smoke. If paint is applied over the seals, it can create a barrier that prevents them from activating properly, delaying their expansion or even rendering them ineffective altogether. This can somewhat compromise the fire-resisting capabilities of the door and potentially endanger the safety of building occupants.
For these reasons, we advise that intumescent seals be left unpainted and clearly visible. If aesthetics are a concern, it’s best to consult with a fire door specialist to explore compliant options that maintain both safety and appearance.
