Perry Shield Intumescent Pads are essential to your Fire Door assembly. Each time a fire door is cut to fit a hinge, lock or latch a weakness is created. This can mean up to four weakened points in a door, which could allow a fire to take hold. Any ironmongery installed on a fire door must be fitted without compromising the integrity of the fire door assembly. This is of particular importance where ironmongery is rebated into the door set, such as hinges, locks and latches.