A closed, properly fitted fire door buys time. In a corridor full of toxic smoke or a flat entrance ablaze on one side, minutes are everything. We get asked daily: how long will fire doors contain fire and smoke? The short answer is 30 to 120 minutes, depending on the door’s rating and whether smoke seals are fitted. 

The more useful answer is this: the door only lasts as long as the entire doorset performs as tested. That means the door leaf, frame, seals, glazing, hinges, latches, and self closing devices all working together, properly installed and maintained.

If you manage blocks of flats, run plant rooms in commercial settings, or you’re replacing a non fire resisting door on a flat entrance, this page will help you choose the right fire rated doors, understand where smoke protection comes from, and know how to keep door performance reliable over years, not months.

What we mean by fire resistance duration

Fire resistance duration is the tested period that a complete doorset resists the spread of fire and smoke. Typical ratings are FD30, FD60, FD90 and FD120. The “FD” tells you the minutes of fire resistance, and the “S” suffix means cold smoke seals are included for smoke control.

• FD30: at least 30 minutes
• FD60: at least 60 minutes
• FD90: 90 minutes
• FD120: up to 120 minutes

In practice, how long fire doors hold back fire and smoke depends on the installation quality, door condition, and whether smoke seals are continuous and undamaged. We see well maintained fire doors in residential buildings deliver dependable performance for years. Poorly maintained ones fail in minutes.

Shop FD30 Internal Fire Doors

The quick answer: how long will a fire door hold a fire and stop smoke?

• A standard FD30 door resists fire for at least 30 minutes. With the S suffix and intact smoke seals, it also limits cold smoke for that period.
• An FD60 doorset offers a minimum of 60 minutes of fire resistance and, with “S,” smoke control.
• FD90 and FD120 are specified where the escape routes or plant rooms need extended protection, or where building type and fire risk assessment indicate higher fire resistance.

So, how long does a fire door contain smoke? For an FD30S or FD60S, the smoke control is intended to last for the same period as its integrity rating, provided the seals are present, continuous, and not painted over.

Will a fire door stop smoke?

Yes, but only if it is an FD30S, FD60S, FD90S or FD120S with cold smoke seals. Those seals control smoke at ambient temperatures when intumescent strips have not yet expanded. A plain FD30 without the S protects against flame and hot gases but is not designed to restrict cold smoke. That is why smoke seals matter so much at flat entrances and along escape routes.

If you need to control smoke spread of fire between compartments, look for the S suffix, verify continuous seals, and ensure the door gaps are 2 to 4 mm. Also make sure any letterplates, viewers, or door panels used are part of the tested configuration.

How fire door ratings are tested and certified

The fire door standards behind those numbers are British Standard BS 476-22 and European Standard BS EN 1634-1. Both measure integrity, and BS EN 1634-1 also measures insulation. Certified fire doors are tested as complete assemblies, not just the door leaf. That point matters a lot in the field. Swap a latch, use the wrong door frame packers, or omit smoke seals and the rated performance is no longer reliable.

When we talk about fire door certification, we mean third-party testing that proves the doorset’s fire resistance and smoke control for a stated time. Reputable fire door manufacturers and fire door suppliers provide evidence of the tests, the permitted fire door components, and installation instructions. Our team checks that our fire doors comply with the relevant fire door regulations before listing them.

Where the time actually comes from: construction and components

Here’s what carries the load when a fire hits one side of a door:

• Fire door construction and materials: modern fire doors typically use engineered timber cores or composite cores with facings and lippings sized for fire resistance. The door edge detail is designed to accept intumescent seals, and in some cases cold smoke seals.
• Fire door frames: must be compatible with the tested doorset, correctly secured into the securing wall, and use specified packers and fixings.
• Fire door seals: intumescent seals swell under heat to seal gaps. Cold smoke seals control the passage of smoke before the fire raises temperatures.
• Fire door hinges and closing devices: use rated hinges and an effective self closing device so the door is fully closed. Self closing devices and closers must be adjusted to overcome latch resistance and seal drag.
• Fire door locks and door handles: must be compatible items listed in the doorset test evidence. The wrong lock case can compromise the door’s performance.
• Fire door glazing: only fire resisting glass and approved glazing systems keep the rating intact. Improvised glazing turns a fire door into a non fire resisting door.
• Fire door thresholds and gaps: the gap between the door leaf and frame must be 2 to 4 mm on the sides and head. Larger gaps defeat both intumescent and smoke seals.

We also look for other third party features that affect smoke control, like automatic drop seals at thresholds on flat entrance doors where air transfer grills are present nearby.

Oak Flush 1 Lite Clear Glazed Fire Door

UK rules that govern fire doors

If you’re the responsible person for a building, two frameworks set your duties.

• Regulatory Reform Fire Safety Order 2005: often called the reform fire safety order or simply the fire safety order 2005. It requires a suitable and sufficient fire risk assessment and ongoing fire door maintenance where doors are part of the fire safety strategies. Building owners and duty holders must keep fire safety measures in good repair and effective.
• The Fire Safety (England) Regulations 2022: in force since 23 January 2023. For multi occupied residential buildings over 11 metres, you must carry out fire door inspection checks of communal areas every 3 months, and check flat entrance doors annually. Flat entrance fire doors must be included in fire safety assessments.

Fire doors must include intumescent seals and self-closing devices. They must be kept closed, or self closing, during normal use. In buildings where residents share communal areas and escape routes, the law expects regular inspections and records.

What affects how long fire doors hold back fire and smoke?

Fire doors varies depending on:

• The rating of the doorset: FD30, FD60, FD90, FD120.
• The presence and condition of smoke seals: without “S,” the door controls flames but not cold smoke.
• Fire door installation quality: improperly installed doors lose performance. A properly installed doorset maintains clearances, uses the right fixings, and seats seals correctly.
• The door’s environment: damp, impact, or unapproved modifications.
• Ongoing fire door maintenance and regular inspections that keep everything within spec.
• Whether closing devices are effective: a door held open or with a weak closer cannot protect anybody.

We’ve seen an FD60 door outperform a poorly fitted FD90 in the field simply because the FD60 was properly installed and maintained.

Shop Internal Fire Doors

Flat entrance doors: what you need to know

Flat entrances are high-stakes locations in blocks of flats and multi occupied residential buildings. Residents rely on those doors to keep fire and smoke out long enough to escape safely or to stay put if that is the plan.

For flat entrance doors, we recommend:

• At least FD30S unless your fire risk assessment indicates FD60S due to building type, height, or layout.
• Continuous smoke seals on the head and jambs, and smoke control at the threshold where required.
• A robust self closing mechanism that latches the door reliably on every cycle.
• Fire resisting glass only where the test evidence allows it.
• Regular resident communication so people don’t remove closers or paint over seals.

We also advise building owners to check flat entrance doors at handover and after refurbishments. Contractors sometimes shave the door leaf to clear new floor finishes and accidentally kill the rating.

Fire door standards and compliance in practice

To keep fire door performance trustworthy:

• Specify doorsets tested to BS 476-22 or BS EN 1634-1.
• Ensure fire doors comply with the building regulations that apply to your building type and use.
• Use compatible fire door components from the test evidence.
• Keep installation and maintenance records as part of your detailed compliance reports.

Many of our clients now store certificates and fire door inspection logs online, providing secure log in for management and auditors. A secure log in with timestamps, photos, and notes turns a once-a-year headache into a rolling record you can trust.

Comparison table: fire door rating and typical use

What we stock and why specification matters

Our range includes certified fire doors in FD30 ratings, suitable for internal use and flat entrances. Where aesthetics matter, we support options with approved fire door glazing systems and durable finishes.

• Free mainland UK delivery with VAT-inclusive pricing, so what you see is what you pay.
• 40+ years of family-run expertise.
• Many products carry a 10-year warranty, and our TrustSpot rating reflects how we stand behind them.

If you’re upgrading flat entrances across a block, we can coordinate direct-from-manufacturer delivery and phased scheduling so communal areas stay open. For project managers juggling multiple trades, that reliability matters more than anything.

Summary and next steps

• How long fire doors contain fire and smoke depends on their rating and condition. FD30 to FD120 is the tested range. Add the S suffix if you need smoke control.
• Fire door performance is doorset performance. The door leaf, door frame, smoke seals, fire door hinges, fire door closers, fire door locks, and any fire resisting glass work together.
• Under the fire safety order and the Fire Safety (England) Regulations 2022, the responsible person must complete a fire risk assessment, keep doors in good repair, carry out regular inspections, and check flat entrance doors at set intervals.
• The big gains come from basics: correct fire door installation, 2 to 4 mm gaps, continuous smoke seals, and an effective self closing device.

Shop Internal Fire Doors