Fire doors are an essential part of any building’s passive fire protection system - but other than their distinctive heaviness and blue sticker, you may not be aware of how fire doors work to protect you from fire.

Learn what makes a fire door different from standard doors, when they’re required and how they protect against fire.
 

How Do Fire Doors Work?

Fire doors are made from layers of various materials, including wood, gypsum, wire mesh, vermiculite, glass, and steel, all of which work together to create a safe door that protects from fire. 

Doors come in different grades, and each one will be rated by how long it can hold up against the fire before disintegration. After fire doors are fitted, the installer will provide the owner with certification to show that the door adheres to building regulations.

It’s vital that in the event of a fire alarm, all fire doors automatically close to block the fire’s path. Fire doors come with a clever retainer system that uses an electromagnet to hold the heavy door open during daily use. When a fire alarm is triggered, the electromagnet system releases the door to allow it to close and protect inhabitants from fire.
 

How Are Fire Doors Different To Normal Doors?

All fire doors must display a blue sticker containing white writing that reads ‘fire door keep shut’. They will also have a manufacturer's fire door label attached to either on the side edge or the top edge of the door (As shown below). If the door does not have one of these labels, then it is not a certified fire door, and will not provide effective protection for your people or your property.

Fire Doors will have a closing mechanism on them to ensure that they firmly close from a halfway position and have heat-sensitive seals around them that expand when heated to protect the integrity of the door and slow down a fire's progress.

There is a range of different materials that you can choose from for your fire doors, using timber and steel in their construction.
 

When Are Fire Doors Required?

In the UK, strict fire safety regulations specify where fire doors are required.

Any Public Building

By law, any building with public footfall must use fire doors to protect the public and the rest of the building. This includes public buildings such as:

• Government Buildings
• Offices
• Prisons
• Restaurants
• Factories
• Shops
    

What Do Fire Doors Do?

Fire doors are classed as part of a building’s passive fire protection system, helping to potentially contain fires when they break out or slow down the rate at which they spread.

They are not designed to be completely immune to fire; instead, depending on their rating, they are designed to hold back the fire for either 30 minutes (FD30), 60 minutes (FD60), 120 minutes (FD120), or 240 minutes (FD240). FD30, FD60 and FD120 doors are available in either steel or timber construction, whereas the FD240 ratings can only be achieved with doors made from steel.
 

Fire Doors Help To Contain Fires

If a fire breaks out in a room with a fire door, it will be contained in that room without spreading to other parts of the building, meaning that the rest of the building is less likely to succumb to the fire.
 

Fire Doors Protect Occupants And Provide A Safe Escape

By installing fire doors along main escape routes and communal areas, occupants of a building on fire will be able to avoid the fire and exit the building safely without coming into contact with the fire or smoke.
 

Fire Compartmentalisation And Passive Fire Protection

Fire Compartmentalisation is the sub-division of a premises into smaller sections or units in which the spread of fire and smoke can be contained. The aim of compartmentalisation is to stop a fire spreading rapidly throughout the whole building, but to hold it back in sub-sections for as long as possible.

Fire Doors are an important part of fire  compartmentalisation, but they are not enough on their own. Fire rated walls that can hold back a fire for 30, 60, 90 or 120 minutes also need to be incorporated into the fabric of a building. The rating of the fire wall specified will depend upon the building's use, and by related building regulations or insurance requirements.

This 'Passive Fire Protection' relies on the fabric of a building being able to contain a fire situation for long enough to allow its occupants to be safely evacuated.

A premises' ability to contain a fire through Passive Fire Protection (PFP) depends on three main factors:

1. That the walls and floors are correctly constructed.
2. That any coatings and penetrations to and through these surfaces are sealed to the same standard of fire rating.
3. That correctly rated Fire Doors, Shutters and Barriers are installed and are inspected regularly.

Whilst PFP is a critical factor in protecting both people and property from the threat of fire, Active Fire Protection is also a legal requirement in the fire strategy for many buildings.

Active Fire Protection includes the installation of Fire Detection and Fire Suppression systems which automatically detect and combat a fire emergency should the need arise.
    

How Safe Are Your Existing Fire Doors?

You might think that because you have fire doors fitted already, you and your property are safe, but is that true? When was the last time you had your fire doors inspected?

There is a legal requirement for those responsible for buildings under the Regulatory Reform (Fire Safety) Order to ensure that all fire doors continue to retain the ability to resist the passage of fire throughout their working life. This means that building owners need to ensure that fire doors are inspected and well maintained if they are to continue to provide the protection that they were designed for.
  

How often should your fire doors be checked? 

As with any other life-saving product, a fire door should be checked regularly to ensure it functions correctly and is ready to use. It should be viewed in exactly the same way as testing a smoke alarm or a fire extinguisher.

It is a vital part of a building's risk assessment to ensure that all fire doors continue to retain the ability to resist the passage of fire throughout their working life, are well maintained in an efficient state, are in efficient working order, and are in good repair. This includes the testing of door closers, hold-open magnets and the integrity of the doors themselves.

It is important to note that a doorset's fire resistance capabilities can be seriously compromised if it is not maintained by a trained engineer who has appropriate knowledge of this complex life safety product. Any slight alteration to the door or its surroundings can affect its fire resistance, so checks should be carried out at least every 6 months, or more frequently depending on the traffic using the door.

Johnson Controls are qualified to inspect, service and maintain all types of fire doors and roller shutters. Contact us using the form further down this page to arrange a full site survey and make sure your fire doors are up to the job.

At Johnson Controls, our wide range of Fire Doors ensures we have a solution for all your passive fire protection applications, whilst our Fire Detection and Fire Suppression solutions can be used to actively fight against.

See our full range of security and fire doors here.