Crittall Fire Doors: Fire Ratings, Compliance and InnerVision Options
- June 29, 2026
- General
Fire-rated internal doors are one of the most important safety features in any building. They slow the spread of fire, protect escape routes and buy vital time for occupants and first responders. The challenge for many architects, designers and homeowners is finding a fire door that meets strict safety standards without sacrificing the slim sightlines and natural light that define modern steel-framed design.
This guide explains fire ratings, compliance and the practical decisions behind specifying Crittall fire doors. It also introduces our Innervision® fire-rated steel doors and screens, supplied and installed by Lightfoot Windows.
At a glance:
- Crittall fire doors combine slim steel frames with fire-rated glazing for protection and natural light.
- Our Innervision® doors carry an FD30 fire rating and comply with BS 476-22.
- Fire doors must be tested and certified as a complete door assembly — leaf, frame, glazing, hinges, seals and closers.
- They suit both residential and commercial properties, from hallways to offices.
- Always confirm your required fire rating with Building Control before ordering.
What are Crittall fire doors?
Crittall fire doors are internal steel doors designed to resist the spread of fire for a set period of time. They use a hot-dip galvanised steel frame, fire-resistant glass panels and certified seals to form an effective fire barrier.
The result is a door that performs as part of a building’s passive fire protection systems while keeping the industrial style that Crittall has been known for since Francis Henry Crittall built the brand’s reputation.
These doors give you:
- Slim steel frames with large glass panels for generous natural light
- A virtually maintenance-free, hot-dip galvanised finish
- Black steel doors, or a wide choice of RAL colours
- Compliance with UK building regulations
Understanding fire ratings
A fire rating tells you how long a door assembly can hold back fire conditions during a fire endurance test. The most common ratings for internal doors are FD30 and FD60.
FD30 vs FD60
FD30 resists fire for 30 minutes. It is common inside dwellings – for example, on protected escape routes or between an integral garage and the house.
FD60 resists fire for 60 minutes. It may be required for higher-risk areas or certain multi-storey and communal settings.
Our Innervision® Fire Rated doors carry an FD30 fire rating. This level of fire resistance prevents the spread of fire for up to 30 minutes, protecting people and property in the event of a fire.
The right fire rating depends on your layout and fire strategy. Your Building Control officer or fire engineer should confirm what your project needs.
Compliance and safety standards
Fire safety is a legal requirement, not an optional extra. To meet UK fire safety regulations, internal fire doors must be third-party tested and certified.
Why the whole door assembly matters
A fire door only performs if every part works together. Certification covers the complete set, not isolated parts. That means:
- The door leaf
- The door frame
- Fire-rated glazing
- Intumescent seals
- Hinges, door closers and ironmongery
Intumescent strips expand under high temperatures to seal gaps around the door frame. These are part of the certified assembly. They must never be omitted or altered.
Proper installation is just as important as correct specification. A certified door fitted incorrectly will not perform as tested. That is why these doors must be installed by professionals in line with the manufacturer’s instructions – and checked regularly to maintain compliance and protect the warranty.
Where FD30 internal fire doors are used
Internal fire doors are introduced where separation is needed between higher-risk rooms and circulation spaces, or where safe escape routes must be maintained.
Typical locations include:
- Hallways and stairwells
- Between an integral garage and the house
- Flat entrance doors
- Doors onto protected escape routes, such as loft conversions
- Internal links between kitchens and corridors
- Plant rooms and communal areas in apartments
They are also specified across commercial buildings and public buildings – offices, hospitality and retail – where safety performance is required but visual continuity still matters.
Door positions and ratings should always be confirmed against the project’s fire strategy before drawings are finalised.
Innervision® design and specification options
Innervision® internal fire doors can be configured to suit a wide range of openings and room layouts. Options include single and double doors, double leaf sets, and compatible side screens or fixed glazing.
Glazing layout, bar positioning and sightlines can be planned to match adjacent steel screens. This keeps the fire-rated elements looking integrated rather than added on.
For a compliant outcome, treat the door as a complete set. Key decisions include:
- Door handing and swing
- Levels of visibility or privacy
- Traffic levels, which influence hardware choice
- How the door lines up with nearby partitions and corridors
Hardware is chosen to support both function and fire safety, including door closers and positive latching where required. Every door can be finished in iconic black steel or your chosen RAL colour.
Things to consider
Certified fire doors differ from standard doors in a few ways:
- Higher cost due to certified construction
- Heavier steel sections and hardware
- Defined size and format limits
- Mandatory professional installation and maintenance
These factors are worth planning for early, so your design and budget stay on track.
Frequently asked questions
Do internal fire doors have to be certified?
Yes. They must be third-party tested and certified as a complete set, then fitted to the manufacturer’s instructions.
Can I have a black steel finish?
Yes. Innervision® fire doors are available in a range of RAL colours, including iconic black steel.
Are double doors available?
Yes. Configurations include single and double leaf hinged doors, plus fixed internal screens.
Looking for fire doors for your next project? Speak to Lightfoot Windows today
As an official Crittall Specialist Partner since 1935, we advise homeowners, architects, contractors and commercial developers on specification, building control compliance and installation – from first enquiry to completion.
Ready to discuss your project or get a free quote? Get in touch with Lightfoot Windows:
- Fill in our online contact form
- Call 020 8662 9090
- Email general@lightfootwindows.co.uk
Want a quick estimate on new Crittall windows or doors? Visit our ‘Get An Estimate’ page, fill out the required information, and one of our friendly experts will get back to you within 48 hours.