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Fitting Fire Doors

The correct installation of fire doors is a critical part of the fire door certification process. Fire door certification can be invalidated if the fire door is not properly installed or is fitted with incompatible fixtures. Incorrectly fitted fire doors will not adequately protect the building or its occupants, potentially putting lives at risk. Fire door installation should therefore only be carried out by a trained and competent individual.

How do you install a fire door?

Every third-party certified fire door will be supplied with fitting instructions. The instructions will be specific to that door and so it is important to adhere to those instructions. The way a fire door needs to be installed may be different depending on the door construction and the environment of the installation.

All fire door furniture, hardware, frames and seals should be compatible with the fire door and should have the same fire rating as the fire door leaf.

Please note: power size EN3 is the minimum required for fire doors that must be fitted with an automatic door closer; EN1 and EN2 are not actually suitable for use on fire doors in accordance with EN 1154.

Unless you are trained and competent at fire door installation, it is advisable to get a qualified fire door installer to fit your fire doors. Fire doors should always be fitted according to the standards set out in Building Regulations. See our guide Fire Door Regulations for more information.

Can fire doors be fitted to old frames?

As the frame of a fire door is classed as one of the components that make up a fire door, it is recommended that the fire door frame is purchased at the same time and from the same manufacturer as the fire door. Using the existing frame is not advisable as the existing frame may not carry the same specifications and fire rating as the door leaf. If you do decide to fit a new door leaf onto an existing frame, a careful check of the frame should be carried out to ensure its fire rating and suitability. This check must be carried out by a qualified person, such as a fire door inspector will be able to assess the suitability of a door frame and advise whether it is possible to retain it when fitting a new door leaf.

In most cases, fitting a new fire door leaf to an existing door frame is more difficult than purchasing a new frame and leaf together. Made-to-measure fire door and frame sets are an ideal solution when replacing a fire door to fill an existing gap. Purchasing a fire door leaf and frame set is the best way to guarantee a compliant door set when correctly installed.

Can you trim a fire door?

There is no general or recommended amount that a fire door can be trimmed. How much can be cut off a fire door depends on the construction of the door and you should refer to the manufacturer for instructions. Modern fire doors often have a lightweight core with less fire resistance. The solid wood lippings around the edges provide a higher fire resistance. If the lippings are trimmed or cut, this may seriously affect the fire door’s ability to resist fire. Cutting or planing the fire door too much will result in the door’s certification becoming void. It is highly recommended that any alterations to a fire door should only be carried out by a fully trained fire door fitter and in accordance with the manufacture’s guidelines for that particular door.

Purchasing a custom-size fire door alleviates any necessity to cut a fire door to try and get it to fit. Fire doors and frames can be made to your specifications to ensure a good fit for an existing opening. This easy-to-use fire door configurator leads you step by step through the process of ordering a bespoke fire rated door and frame to your exact specifications.

Can a fire door be painted?

Fire doors can be painted with regular decorative paint or finished with varnish without affecting their performance. Care should be taken when applying the paint or varnish not to cover the seals or hardware. It is best to avoid using heat or chemical paint strippers if the fire door has intumescent seals in place.

Alternatively, pre-finished fire doors can be purchased, saving time and in many cases labour costs. Our custom-made fire doors are available in a wide range of finishes including real wood veneer, Formica or painted in any RAL colour of your choice.

Is my fire door fitted correctly?

Complete our 6-step fire door check to ensure your fire door is compliant and fitted correctly. A fire door gap checker can help you assess whether the door is correctly fitted with 2-4mm gaps between the door leaf and the frame. If you are unsure about the integrity or fitting of your fire door and frame we recommend that you have them assessed by a qualified person.

Can you add glass to a fire door?

Modifying a fire door by adding a vision panel can be done but only in accordance with the door manufacturer’s instructions and only by a trained and competent individual. The glazing must be heat-resistant and fire-rated to the same specifications as the door leaf. Failure to comply with these specifications would lead to the fire door certification becoming void.

It is advisable to purchase a fire door with pre-fitted glazing that has been added by the manufacturer. Fire doors are available with a wide range of glazing sizes and options including wired, plain or frosted glass.



Who can install a fire door?

Fire doors must be installed by a trained and competent person such as a qualified fire door installer.

Can you upgrade an existing door to a fire door?

No, most normal internal doors cannot be upgraded to a fire door because of their construction. Normal doors are not built to withstand fire and are often hollow or lightweight and liable to warping. Upgrading a normal door to a fire door is a very specialist skill and would be incredibly time consuming. It is far easier and more cost-effective to purchase and install a new fire door. Fire doors can be made-to-measure to fit existing openings.

Do I need to use special paint on fire doors?

No, special paint is not required on fire doors. Regular decorative paint or varnish can be used without affecting the performance of the fire door. Care should be taken not to paint over the seals or hardware such as hinges.

How many hinges do you use to install a fire door?

Most fire doors require 3 fire-rated hinges to fix the door leaf to the frame. The hinges should feature a CE mark and fire identification stamp. Occasionally, depending on the weight of the fire door, more hinges may be specified by the manufacturer.


Reviewed: 29/03/2022 (doc:568 V1.0). Our articles are reviewed regularly. However, any changes made to standards or legislation following the review date will not have been considered. Please note that we provide abridged, easy-to-understand guidance. To make detailed decisions about your fire safety provisions, you might require further advice or need to consult the full standards and legislation.


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