Understanding Fire Door Components
A fire door is a system, not just a door leaf. Each component plays a specific role in fire protection. Understanding these components helps you identify issues and make informed decisions about repairs.
Intumescent Seals
What they do: Intumescent seals are strips fitted into grooves around the door edge or frame. When exposed to heat (typically around 200°C), they expand dramatically - up to 20 times their original size - filling gaps and preventing fire spread.
Signs of problems:
- Seals painted over (paint prevents expansion)
- Seals pulling away from grooves
- Visible damage, cracks, or missing sections
- Hardened or brittle material
Repair options: Damaged seals should be removed and replaced with new intumescent strips. This is a straightforward repair that restores fire protection.
Typical cost: £30-£50 per door
Smoke Seals
What they do: Smoke seals (brush or blade type) prevent cold smoke from spreading through gaps when the door is closed. They work at lower temperatures than intumescent seals and provide protection before fire reaches the door.
Signs of problems:
- Missing brush strips
- Damaged or flattened blades
- Visible gaps when door is closed
- Smoke smell passing through closed door
Repair options: Smoke seals can be replaced independently. Combined intumescent/smoke seals are also available.
Typical cost: £25-£40 per door
Self-Closing Devices
What they do: Self-closers ensure the door closes automatically from any angle. Fire doors must close fully and latch without manual intervention.
Types:
- Overhead closers - visible arm mechanism mounted at top of door
- Concealed closers - hidden within door or frame
- Floor springs - mounted in floor (less common in fire doors)
Signs of problems:
- Door not closing fully from all angles
- Door slamming or closing too fast
- Door bouncing open after closing
- Visible damage to closer mechanism
- Oil leaking from hydraulic closers
Repair options: Many issues can be resolved by adjustment. Worn or damaged closers may need replacement.
Typical cost: £40-£80 per door
Hinges
What they do: Fire door hinges must support the door weight and maintain correct alignment. Most fire doors require three hinges, and they should be fire-rated (typically CE marked).
Signs of problems:
- Door sagging or dropping
- Screws pulling out of frame
- Visible wear or damage
- Only two hinges fitted
- Non-fire-rated hinges installed
Repair options: Loose hinges can often be re-secured. Damaged hinges or incorrect types require replacement.
Typical cost: £30-£60 per door
Latching Mechanisms
What they do: Fire doors must latch securely when closed. The latch holds the door in the closed position against pressure from fire.
Signs of problems:
- Door not clicking shut
- Latch not engaging with strike plate
- Strike plate misaligned
- Latch mechanism worn or damaged
Repair options: Often resolved by adjusting strike plate position or latch mechanism. Worn components may need replacement.
Typical cost: £30-£60 per door
When to Repair vs Replace
We always assess repair options first. Replacement is recommended when:
- Door leaf is damaged beyond repair
- Door has been modified (holes, cut-outs)
- Certification cannot be verified
- Multiple components need replacement
- Repair cost approaches replacement cost
Frequently Asked Questions
Can I do fire door repairs myself?
Some basic maintenance can be done by competent persons, but repairs affecting fire performance should be done by qualified professionals to maintain compliance.
Do repairs affect the door's fire rating?
Properly executed repairs using correct materials maintain the fire rating. Incorrect repairs or modifications can compromise fire performance.