How to Repair a Damaged Fire Door

Practical Guide #8

For: Joiners, caretakers, inspectors, and maintenance teams responsible for keeping fire doors compliant.

Why Repairs Aren’t Straightforward

A damaged fire door can’t be treated like any old door. Even small repairs can compromise its fire integrity, especially if they affect the core, edge sealing, hardware zones, or vision panels.

This guide explains what can and cannot be repaired, how to do it correctly, and when replacement is the only compliant option.

1. Assessing the Damage

Before you touch anything, inspect the door thoroughly:

• What type of damage is present?

  • Split or delaminated core?

  • Chipped edges?

  • Surface dents?

  • Loose ironmongery?

  • Damaged vision panel?

• Where is the damage?

  • Edge of the door (hinge/lock/closer area)?

  • Centre panel?

  • Bottom rail?

• Is there an FD30 or FD60 label still intact?

• Is the door-set manufacturer known?

The repair method (or whether it’s even allowed) depends heavily on the location and extent of the damage.

2. Repairs That Are Commonly Acceptable

Certain surface-level or cosmetic issues can usually be repaired, provided the door’s test evidence permits it:

Surface Damage (Dents, Scratches, Minor Indents)

• Can be filled using fire-rated wood filler or intumescent-compatible repair compound

• Sanded back and repainted or re-lacquered

Edge Chips or Minor Breakout

• If small (e.g. ≤5mm deep, <100mm length), may be patched with fire-resilient hardwood insert

• Use fire-rated adhesive and match the lipping if present

Loose Hinges or Ironmongery

• Can often be re-fixed using longer steel screws of correct gauge

• If the timber is stripped, repair using fire-rated two-part filler, or plug and re-drill using hardwood dowels

• Intumescent pads must be replaced if disturbed

Surface Delamination

• If facing/veneer is lifting and the core is intact, can be re-adhered using high-temperature-rated adhesives

• Clamp and cure per adhesive spec

Always consult the original Field of Application (EXAP) document if available — it governs what repair methods are permitted.

3. Repairs That Are NOT Normally Acceptable

Core Penetration

• Holes or cuts into the core (e.g. cable runs, security locks) usually invalidate the fire performance

• Replacing the leaf is often the only compliant option

Alterations to the Edge

• Trimming more than permitted tolerance (typically 3mm on any edge unless otherwise stated) invalidates the door

• Any cut into the top, bottom, or lock edge must be backed by manufacturer guidance

Vision Panel Modifications

• Replacing glass or re-glazing without tested methods is not compliant

• Any change to aperture size, glass type, or bead system requires re-certification

Missing or Painted-Over Seals

• If seals are missing, perished, painted, or partially detached — they must be replaced

• Partial seal replacements should be full length per side — never patch-repaired

4. Repair Best Practices

• Record all damage and proposed repairs

• Take before and after photos

• Use only fire-rated or intumescent-compatible materials

• Document all filler types, adhesives, and fixings used

• Note any changes to gaps, hinges, closer behaviour, or latch operation

If working in a commercial or social housing environment, log everything in the building’s fire door maintenance record.

5. When to Replace the Door

You should always consider full replacement when:

• The label is missing and you can’t confirm certification

• The core is cracked, soaked, or compromised

• The frame has separated from the wall

• Ironmongery zones are crushed or distorted

• The door leaf has warped beyond tolerance

• A previous repair has already been attempted and failed inspection

Summary Checklist

✅ Can Repair	❌ Replace Required
Surface dents/scratches	Damaged core
Minor edge chipping	Over-trimmed edge
Loose ironmongery	Modified vision panel
Veneer lift	Missing certification
Painted-over seals (if fully replaced)	Severe warp or twist