Tag Archives: smoke seals

Purpose of Fire Internal Fire Doors

fire-doorsMost commercial buildings will have fire doors located throughout. Fire doors are used in specific locations in the building to prevent a fire from spreading form one room to another. Fire doors are typically located on door ways that open out onto hallways or staircases. These areas are used by the occupants of the building to escape in the event of a fire outbreak, therefore it is important that they are protected for as long as possible with fire doors.

During the design of the building a lot of thought goes into the necessary fire protection requirements. Internal fire doors are a key component. Doors are selected with particular performance levels in mind. Fire doors are graded in terms of time periods. A typical time period could be a half hour fire door. This means that the door will last for about 30 minutes before the integrity of the door will fail. Other fire doors may be one hour. This fire rated door may be used separating large compartments within the building. If a higher rated door is required, for example a four hour door, then a steel door may be required. This door might be used in a boiler room for example.

A typical fire door may look similar to any other non fire doors in the building. The difference will be the internal structure of the door. The internal core of the door will incorporate non combustible materials to help prolong the life of the door during a fire. The door itself is not the only component that makes up a designated fire door set. The door panel is obviously critical but it is useless if the door is left in the open position during a fire. To ensure that the door is always in the closed position, an automatic door closer is usually fitted at the top of the door. This is a spring loaded device mounted on the door and connected to the frame that will close the door every time after a person has gone through it.

Statistics have shown that smoke is one of the main causes of fatalities during a fire. For this reason it is important to prevent the movement of poisonous fumes around the building, especially into the escape routes. To prevent this, cold smoke seals are fitted to the edges of the fire doors. The cold smoke seals prevent smoke from passing between rooms. In-tumescent strips are also fitted to the door edges. This is another seal that will expand if subjected to intense heat, closing off the gap between the door edge and the door frame, stopping heat and fumes passing through and spreading the fire to the next compartment.