What are fire doors made from?
There are various types of fire doors, and selecting the right one is critical in performance and price. In general, a door made using many materials will be costly compared to a door made of just timber. However, a door made of less material is more likely to distort and ineffective at preventing a fire from spreading through a building and will have a lower fire door rating e.g. FD30 rather than FD60 or FD90. Therefore it is imporant that we understand what fire doors are constructed from.
In this article, we will cover what fire doors are made from. Timber is used because most often as it is readily available and had a very predictable char rate. See below:
Timber fire doors
The hollow core doors are the lightest and cheapest alternative. The doors are not open but are instead made around a hardwood with veneer applied. The inner frame of cardboard or the honeycomb makes the hollow door stable, while the solid wood is used in the area where the catch, locking mechanisms, and handle are positioned. They are commonly used as interior doors in residential homes where heat strength and insulation are not vital. However their lower weight makes them more suited to buildings like care homes.
Tubular Core are light weight and offer great stability. Compared to solid boards, the weight of Tubular Core is reduced by up to 60%. Therefore they are much easier to open.
Tubes are installed into the door during the installation process that are later removed meaning that there are hollow areas in the core, this how the weight is reduced so much. See picture below:
Solid core doors
These are fire doors with a solid core made from many materials and are commonly coated with a natural wood veneer to give them the appearance of a solid door but at a lower cost. They are heavier and provide better insulation compared to hollow wood doors. Therefore they are more suited to higher rated doors such as FD60.
Streboard fire doors
Strebord® particleboard is a very versatile and widely used product. It is very robust and can be easily fabricated to produce a wide range of fire doors. Streboard is the top selling door core in the UK and it is highly suited to many installation and maintenance scenarios.
Steel Fire Doors
Steel fire doors have a variety of door cores. However, we will take you through the five most common steel door cores ranging from the most expensive to the least costly.
1) The temperature rise doors
The temperature rise door is the most expensive fire door under the metal types. It is resistant to fire, and its laminated construction slows down the passage of heat from one region to another, giving the building’s occupants enough time to escape. Hence their increased price.
2) Steel stiffened fire doors
They are the second most expensive. The doors feature steel ribs welded around the door skin, and thus, they are frequently used as security doors since they are difficult to cut or breakthrough. The steel ribs give the door more stability and strength hence increasing its lifespan.
3) Polyurethane fire door
It is the third most expensive metal fire door. Its laminated construction, just like that in the temperature-rises fire door, making it ideal for exterior doors in cold-weather regions.
4) Polystyrene fire door
They are the fourth most expensive metal fire door, and they also feature laminated door construction. The doors have solid insulating capabilities. Doors made of polystyrene are those that require an R-rating or a U-factor. The R-rating is used to access the rate of heat transmission, while the U-factor reflects the rate of heat acquisition and loss.
5) Honeycomb fire door
It is the cheapest of the five most common types of metallic fire doors. It can be used as either an exterior or interior door in areas with little requirement for good heat insulation. Though it is the most affordable type among the metallic fire door, it is the least safe choice.