Fire Rated Door Guide: Ratings, Components and SCDF Rules

A fire rated door looks much like any other solid door, but it does a very specific job. When a fire breaks out, it holds back flames, heat and smoke for a defined period so that people can escape and the fire is contained within one part of the building. In Singapore you will find fire doors on flat entrances facing common lobbies, on exit staircases, plant rooms and compartment walls in almost every multi-storey building.

This article explains what a fire rating means, why a fire door is an assembly rather than a single product, the key requirements in SCDF’s Fire Code, and the common mistakes during renovation that quietly cancel a door’s protection.

What a fire rating means

Fire doors are rated by the period for which they have resisted a standard fire test, typically expressed in fractions of an hour or in minutes, such as half-hour or one-hour doors. During the test, a full door assembly — leaf, frame and hardware — is installed in a test wall and exposed to a furnace on one side that follows a standardised time-temperature curve.

Two performance criteria are central. Integrity is the door’s ability to prevent flames and hot gases passing through gaps, cracks or openings. Insulation is its ability to limit the temperature rise on the unexposed face, so that materials on the safe side do not ignite and people can pass close by. Depending on the location, the requirement may focus on integrity, or on both integrity and insulation. Smoke control is a related but separate matter, addressed through seals and closing devices.

The parts that make up a fire rated door

The most important idea about a fire rated door is that its rating belongs to the tested assembly as a whole, not to the leaf alone. Replace one component with an untested one and the assembly may no longer perform as tested. The main parts are:

Door leaf — a solid core, often of mineral or timber-based fire-resisting material, with facings and lippings that do not compromise the tested construction.
Frame — timber or steel of the tested section, fixed securely into the surrounding wall, with the gap between frame and wall properly sealed with fire-resisting material.
Intumescent seals — strips in the frame or leaf edge that expand when heated, closing the gap around the leaf.
Smoke seals — flexible seals that limit cold smoke leakage before the intumescent material activates, where required.
Hinges — of an approved type with adequate number and fixing to hold the leaf in place as the frame and leaf distort in heat.
Self-closing device — to ensure the door closes and stays closed after each use.
Locks, latches and other ironmongery — compatible with the tested assembly, without large cut-outs that weaken the leaf.
Vision panels — where fitted, of fire-resisting glass in a tested glazing system.

The door also depends on the wall around it. A fire rated door in a wall of lower fire resistance, or with unsealed service penetrations beside it, does not give the compartment its intended protection; that wider picture is covered in our guide to fire protection of structures.

SCDF Fire Code requirements

In Singapore, fire doors are governed by SCDF’s Code of Practice for Fire Precautions in Buildings, commonly called the Fire Code. Its provisions on the protection of openings set out, among other things, the following requirements for fire doors:

Rating — fire doors must have the fire resistance required by the relevant parts of the Code. The explanatory notes indicate that doors to exit openings of apartments, protected staircases, protected lobbies, exit passageways and compartment walls should have at least half-hour fire resistance, with higher ratings where the Code requires them.
Standard — fire doors, where required, are to be constructed and installed to the specifications of SS 332, the Singapore Standard for fire doors, and hinges must be of an approved type complying with SS 332.
Certification — fire doors are required to be listed under a recognised certification body, and regulated fire safety products fall under SCDF’s product listing arrangements.
Self-closing — every fire door must be fitted with an automatic self-closing device capable of closing the door from any angle and overcoming any latch, with limited exceptions such as the bolted leaf of a two-leaf entrance door to certain residential units. Faulty closers are to be repaired promptly.
Hold-open devices — where a closer would obstruct normal use, a door may be held open only by approved means such as a fusible link or an electromagnetic or electromechanical device that releases on smoke detection or alarm. Wedges and hooks are not acceptable.
Escape doors — fire doors on escape routes must open from the inside without a key, tool, special knowledge or effort.

The Fire Code is revised from time to time, and the detailed requirement for any door depends on the building’s purpose group, its location in the escape route and the compartment it protects. Designers should always work from the current edition, and fire safety works in most buildings require plans submitted by a Qualified Person. Our guide to the fire safety certificate in Singapore explains how that approval process fits together.

Fire rated doors in HDB flats and condominiums

The Fire Code requires fire-rated entrance doors for residential units, with an exception where the unit faces an external corridor that has been assessed to dissipate heat and smoke adequately. In practice, that means many flats opening onto an enclosed common lobby, especially in point blocks and condominiums, have fire-rated main doors, while many corridor-access flats do not.

If your main door is fire-rated, HDB advises that its door closer must not be removed. Before replacing such a door, check the HDB renovation permit requirements or your management corporation’s rules to see which approvals and suppliers apply, and use a door assembly that is certified for the required rating rather than a lookalike. For condominiums, the MCST typically sets renovation rules for main door changes because they affect the common lobby’s fire protection.

Renovation mistakes that defeat a fire door

Most fire doors that fail in a real fire do so not because of the product, but because of what was done to them afterwards. Common problems include:

Removing or disconnecting the door closer, or propping the door open with a wedge.
Cutting the leaf for letter plates, peepholes, larger locks or digital locksets that are not approved for that assembly.
Planing down the leaf after a floor finish change, leaving large gaps at the edges or bottom.
Painting over intumescent and smoke seals, or removing them.
Replacing hinges or ironmongery with non-compliant items.
Re-hanging a certified leaf in a different, uncertified frame, or fixing a new frame without fire-resisting packing.
Overlaying the leaf with decorative laminates or panels that were not part of the tested assembly.
Removing or painting over the certification label, which makes the door’s status impossible to verify later.

If you need a smart lock, a vision panel or a different finish on a fire rated door, the safest route is a door assembly supplied with those features already tested and certified.

Inspection and maintenance

A fire door should be checked periodically, particularly in common areas. Open the door fully and release it: it should close completely and latch from any angle without slamming. Check that the gaps around the leaf are even and not excessive, that seals are intact and unpainted, that hinges are tight with no missing screws, and that the leaf is not damaged or split. Check that labels are still present and legible. In commercial and multi-tenant buildings, defects found during inspection should be rectified promptly, because building owners have ongoing obligations to maintain fire safety provisions in good working order.

Frequently asked questions

What does a half-hour fire rated door mean?

It means the door assembly has resisted a standard fire test for at least 30 minutes against the relevant performance criteria, typically integrity and in some cases insulation. The rating applies to the complete tested assembly of leaf, frame, seals, hinges and hardware installed correctly, not to the leaf alone.

Can I install a digital lock on my fire rated main door?

Only if the lock and any cut-outs are compatible with the door’s certified assembly. Large cut-outs or non-approved locksets can compromise the door’s fire performance. Check with the door supplier, HDB or your management corporation and choose a lock that is approved for use on that fire door.

Is it illegal to remove the closer from a fire door?

The Fire Code requires fire doors to have automatic self-closing devices, and HDB advises that the closer on a fire-rated main door must not be removed. Removing it means the door may be open when a fire starts, which defeats its purpose. If the closer is faulty or too strong, have it adjusted or replaced rather than removed.

How can I tell if my door is fire rated?

Certified fire doors usually carry a label or mark, often on the edge of the leaf or on the frame, identifying the certification. Other clues are intumescent strips in the frame or leaf edge, a self-closer and a heavy, solid leaf. If you are unsure, the building’s management, HDB or the original approved plans can confirm it.

Do fire doors need to be inspected?

Yes. Self-closers, seals, hinges and gaps deteriorate with use. Periodic checks that the door closes and latches properly, that seals are intact and that the leaf has not been altered help ensure it will work when needed, and building owners are responsible for keeping fire safety provisions maintained.

Planning works that affect fire doors, compartment walls or escape routes? Talk to our consultancy or get in touch for coordinated, accountable advice.