Fire door ratings aren’t a label you choose for looks; they determine exactly how long a door holds back fire and smoke. 

 

Whether you’re specifying doors for a new development, replacing a flat entrance door, or trying to make sense of a fire risk assessment, the question of “FD30 or FD60” comes up constantly, and getting it wrong isn’t just a paperwork issue; it’s a genuine safety and compliance risk. 

 

This guide explains exactly what FD30 and FD60 mean, what the ‘S’ suffix adds, where each rating is typically required, and how to work out which one your building actually needs. 

 

What Do FD30 and FD60 Actually Mean?

The number in a fire door rating refers to the length of time, in minutes, that the doorset can resist fire under standard test conditions. 

 

• FD30 fire door: Designed to provide a minimum of 30 minutes of fire resistance.
• FD30S fire door: Provides a minimum of 30 minutes of fire resistance, plus smoke control to limit the spread of cold smoke.
• FD60 fire door: Designed to provide a minimum of 60 minutes of fire resistance.
• FD60S fire door: Provides a minimum of 60 minutes of fire resistance, plus smoke control to limit the spread of cold smoke.

 

EU classifications (EN 13501-2)

The UK is moving away from FD ratings to the European classification system. From September 2029, Approved Document B will only recognise EN classifications for fire resistance, so you’ll increasingly see these on specifications:

 

• E30 / E60: A minimum of 30 or 60 minutes of integrity, meaning the door stops flames and hot gases from passing through. These are the closest match to FD30 and FD60.
• EI30 / EI60: A minimum of 30 or 60 minutes of integrity plus insulation, limiting heat transfer to the unexposed side of the door. This is a higher standard than FD ratings require.
• Sa: Smoke control at ambient temperature, the EU equivalent of the “S” suffix (e.g. E30 Sa is broadly comparable to FD30S).
• S200: Smoke control at both ambient and medium temperatures (up to 200°C), a more demanding smoke test than Sa.

 

These ratings are based on testing against recognised standards such as BS 476-22 or BS EN 1634. They’re not just a name printed on a door. The rating only holds if the complete doorset (leaf, frame, seals, hinges, and closer) has been tested and certified as a complete unit.

 

FD30 vs FD60: Quick Comparison

 

Feature	FD30	FD60
Fire resistance time	Minimum 30 minutes	Minimum 60 minutes
Typical door leaf thickness.	Around 44mm	Around 54mm
Typical use	Flat entrance doors, escape corridors, stairwells	Higher-risk areas, plant rooms, some compartment lines
Smoke control option	FD30S	FD60S

 

Thickness alone doesn’t determine the rating; it’s a common by-product of the construction needed to achieve it, not a substitute for proper testing and certification. 

 

What Does the ‘S’ Mean? FD30S vs FD60S Explained

You’ll often see FD30S or FD60S rather than the plain FD30/FD60 label. The ‘S’ indicates the doorset also provides smoke control, typically achieved through smoke seals fitted alongside the intumescent seals. 

 

• FD30S fire door: A 30-minute fire door with smoke seals fitted.
• FD60S fire door: A 60-minute fire door with smoke seals fitted. 

 

This distinction matters more than it might first appear. In many real fires, smoke causes more harm than flame, and it travels much faster. A door can be technically ‘fire rated’ and still allow smoke to leak through if it’s missing the seals needed to stop it. 

 

FD30S is the typical specification for flat entrance doors, which is exactly the kind of doorset we manufacture for the housing sector. See our social housing fire doorsets and communal area fire doors for more detail. 

 

Where Is Each Rating Typically Used?

Where FD30 Doors Are Typically Required

• Flat entrance doors, usually specified as FD30S.
• Doors opening onto protected escape corridors.
• Stair and lobby doors in many residential and lower-risk buildings.
• Lower-risk internal doors separating rooms from circulation spaces.

Where FD60 Doors Are Typically Required

• Higher-risk locations where extended fire resistance is needed.
• Plant rooms and service risers.
• Certain compartment lines within larger or more complex buildings.
• Areas where evacuation may take longer, or where the fire strategy calls for extended protection.

 

Does the Rating Change for Internal Doors Within a Flat?

• The flat entrance door: Usually FD30S, since it faces the communal escape route and forms part of the building’s wider compartmentation strategy. 
• Internal doors within the flat (e.g. to a kitchen): The required rating depends on the building’s own fire strategy, not a blanket rule that applies to every flat. 
• Internal doors in a commercial or residential-type building: Generally follow the same subdivision logic as the wider escape route. 

 

Treating every internal door in a flat as automatically needing the same rating as the entrance door is a common assumption — and not always a correct one. If you’re specifying or replacing internal fire doors for flats or shared residential buildings, our Safer Homes Range internal doorsets are built specifically for this application. 

 

Is FD60 Better Than FD30?

Not necessarily. It’s natural to think more minutes means more protection, but installing FD60 where FD30 is required doesn’t automatically improve compliance. 

 

Fire safety law requires the door to match the building’s fire strategy and its tested certification. Over-specifying without the right evidence, installation, or compatibility can still leave you non-compliant, even with a ‘stronger’ door in place. 

 

The right rating is the one that matches what your fire strategy actually calls for, not just the higher number. 

 

Choose the Doorset, Not the Label

One of the most common misunderstandings we see is treating FD30 or FD60 as a label that can be applied to any door. In reality, the rating depends on the complete tested doorset — the leaf, frame, seals, hinges, closer, and glazing, tested and certified together. 

 

A few things that can quietly invalidate a rating without anyone realising: 

• Replacing the door leaf only, without checking the rest of the doorset remains compliant.
• Missing or damaged intumescent and smoke seals.
• Incompatible hinges, closers, or letter plates swapped in after installation.
• Installation gaps or tolerances outside the tested specification. 
• Undocumented alterations with no evidence trail to confirm the doorset still matches its certification. 

 

If you suspect an existing doorset may no longer match its original certification, our fire doorset maintenance service can help confirm what’s actually in place versus what should be. 

 

FD30 vs FD60 Guidance: How to Choose Between Them

1. Check the fire strategy or design intent 

A documented fire strategy should specify the required rating by door location. If one doesn’t exist, that’s a risk in itself. 

1. Refer to Approved Document B guidance 

This sets out the fire resistance typically expected for compartment walls, floors, and protected escape routes. 

1. Consider occupancy and risk profile

A low-risk office corridor is a very different scenario to a high-risk residential building or a care setting with vulnerable occupants. 

1. Verify certification and door markings

Looking for certification labels, plug markings, and installation documentation to confirm the doorset meets what’s required. 

 

If you’re unsure which rating applies to a specific building or door location, contact our team — they can talk you through it based on the doorset and building itself, not just general guidance. 

 

UK Regulations Governing Fire Door Ratings

• The Regulatory Reform (Fire Safety) Order 2005 places a duty on the ‘responsible person’ to ensure fire safety measures, including fire doors, are in place and properly maintained. 
• Approved Document B sets out expected fire resistance standards for compartment lines and protected escape routes. 
• The Fire Safety (England) Regulations 2022 introduced specific duties around checking flat entrance and communal fire doors in residential buildings. 

 

None of these set out FD30 vs FD60 as a simple choice, but they establish the framework your building’s own fire strategy needs to work within. 

 

Common Mistakes When Specifying Fire Door Ratings

• Replacing a door leaf only and assuming the original rating still applies. 
• Missing or damaged smoke seals on doors that should be FD30S or FD60S. 
• Incompatible ironmongery, including hinges, closers, or latches that don’t match the certified system.
• Poor installation gaps and tolerances that fall outside the tested specification.
• No certification, records, or inspection history to evidence compliance.

 

Frequently Asked Questions

Is FD60 always better than FD30?

Not necessarily. FD60 provides longer resistance, but the correct rating must match your building’s fire strategy and certification requirements. Over-specifying doesn’t automatically improve compliance. 

 

What’s the difference between FD30 and FD30S?

FD30S includes smoke seals in addition to the standard 30-minute fire-resisting construction, giving it smoke control as well as fire resistance. Plain FD30 doors are not required to include smoke seals. 

 

Are flat entrance doors usually FD30 or FD60?

Most flat entrance doors are specified as FD30S, though the exact requirement depends on the building’s design, height, and documented fire strategy. 

 

Can I replace just the door leaf and keep the FD rating?

Not reliably. Fire resistance is based on the complete certified doorset, including the leaf, frame, seals, and ironmongery. Replacing the leaf alone can undermine the rating even if the new leaf looks identical. 

 

What rating do internal fire doors need?

It depends on the building. Internal doors within a single house rarely need a fire rating at all, while internal doors within a flat that sits in a larger building depend on that building’s fire strategy, not a fixed rule. 

 

How much do FD30 and FD60 doors typically cost?

Cost varies significantly depending on certification, glazing, finish, and whether you’re buying a certified doorset or a door leaf alone. As a manufacturer, we’d always get a specification-based quote rather than relying on generic price guides, since the cheapest option on paper isn’t always a genuinely compliant one.