Fire door hinges explained

Grey internal doors

A door’s hinges are extremely important. They ensure that the door opens and closes properly, and that access to and from your living space is unencumbered. When hinges stick, warp, rust or get painted over, it can lead to sticking, jamming and difficulty accessing areas of your property. This is bad for all internal doors, but especially for fire doors.

A fire door is necessary when connecting living spaces to shared areas such as corridors and stairwells. They are also necessary for business properties and shared accommodation to ensure that the fire escape is accessible and that fires that break out in living areas are not allowed to impinge on the fire escape route.

Fire door hinges are the unsung heroes of your fire doors, ensuring that the leaf moves freely, and enabling the door to be properly opened and closed in the event of a fire. Here, we’ll look at everything you need to know about your fire doors’ hinges.

Do fire doors need hinges?

Yes, absolutely. Hinges are essential in maintaining ingress and egress from your internal fire doors if a fire should break out. Nonetheless, your internal fire doors need specially made hinges that are designed specifically for use in fire doors. Fire doors are thicker and heavier than standard internal doors. While most internal doors are around 35mm thick, a fire door is 44mm in thickness, with a denser core.  As such, they need larger and stronger hinges. While a 75mm x 50mm hinge is a good size for most internal doors, fire doors need a hinge that is around 102mm x 75mm.

Fire door hinges must also be made from a metal with a higher melting point. They are typically made from metals like brass, stainless steel or phosphor bronze which have a melting point of 800 degrees centigrade. Using hinges made from thermally softening metals like aluminium may cause fire doors to shift in their frame. This compromises the seal between the door leaf and the frame, allowing heat and smoke into your home.

Under The Construction Products Regulations introduced in 2011, all fire door hinges must bear the CE mark to ensure fire safety compliance. Hinges are covered by BS EN 1935 safety standards.

How do fire door hinges work?

Fire door hinges work by supporting the door leaf in its frame, even as the surrounding air reaches extremely high temperatures. They prevent heat and smoke from seeping out through the tiny gaps between the door leaf and the frame by maintaining a consistently tight seal around the door’s circumference. A fire door will also use intumescent strips which expand upon reaching temperatures above 200°C to seal this gap, a smoke seal that prevents smoke particulates from escaping through the gap, or both.

Without a fire door hinge, the fire door leaf may shift in position or even fall free of the frame, allowing smoke and heat to pass through the threshold.

How many hinges should a fire door have?

Unlike most internal doors, fire doors are required to have at least 3 sets of hinges. This is to ensure the door’s stability in the frame, and to support the weight necessitated by the fire door’s construction. FD30-rated fire doors typically weigh around 35-45kg while FD60-rated doors can weigh more than 75kg. By contrast, most standard internal doors weigh around 20kg.

Fire door hinges also require very particular spacing to ensure compliance and support the weight of the door while facilitating an easy opening and closing action.

How to add hinges to a fire door

It’s important to note that if you own a business premises or investment properties with private tenants, you will be unable to install your own fire hinges. UK regulations state that fire doors and their hinges must always be fitted by a certified professional, such as a trained joiner or carpenter. This is because even the tiniest inconsistency in the gap between the door leaf and frame can lead to the escape of heat and smoke, potentially nullifying the capabilities of the fire door.

If you are installing fire door hinges in your own home, this is legally acceptable. However, it is still recommended that you leave fire door installation to a trained professional. Self-installation can be risky and potentially make your household more vulnerable in the event of a fire. Only attempt this if you are extremely confident in your DIY capabilities.

If you wish to add hinges to your own fire door hinges, be sure to follow these installation tips:

  • Ensure that the top hinge is positioned with a margin of 120-180mm from the head of the door to the top of the hinge
  • The bottom hinge should then be positioned with a margin between 200 and 250mm from the foot of the door to the bottom of the hinge
  • The middle hinge should be either equal in distance between the top and bottom hinge, or between 200 and 250mm beneath the top hinge
  • Doors over 2400mm tall or wider than 926mm may require 4 hinges to bear their weight
  • A properly fitted fire door should have a gap of no more than 5 mm between the leaf and the frame

Browse our range of internal fire doors 

Combined with the right hinges, an internal fire door can be an invaluable asset to your home that keeps those closest to you safe in the event of a fire. What’s more, with our spectacular range of internal fire doors, protection doesn’t have to come at the expense of style. Whatever your tastes, we have the internal fire doors for you.

From the classically timeless designs of yesteryear to minimalist masterpieces with a contemporary flavour, our internal fire door range has what you’re looking for. You’ll find ready-finished, primed, unfinished and glazed fire doors in a wide range of styles and sizes!