Fundamental function of every fire door is to stop fire and smoke from spreading as the smoke can be an even greater threat to life than fire itself especially when plastic or synthetic materials are burning which may cause high toxic gas emission. Inhaling of such substances may lead to serious poisoning or even death in minutes.

Fire doors must be equipped with certified closer and an adequate lock. Function of the closer is to close the door tight and lock’s function is to stiffen it so the doors won’t tilt even under large pressure. One of the key components that help to prevent smoke from filtering around the door and flames from spreading beyond the door is an intumescent seal. It’s the most unnoticeable element of every fire door which is placed around the edge where the door meets the doorframe. Intumescent seal expands to many times its original size when exposed to high temperature and filling the gap around the door. Seals that are fitted and maintained properly can reduce smoke penetration to almost zero.