When is a fire curtain an acceptable alternative to a fire door?

A fire curtain is an acceptable alternative to a fire door when the opening geometry, traffic flow, or aesthetic requirements make a rigid door impractical, and when the applicable fire resistance classification can be met by a tested, CE-certified curtain assembly. The critical condition is that the curtain achieves the same or equivalent classification required by the project’s fire safety calculation, not simply that it fits the opening. The sections below unpack where codes permit this substitution, what classifications curtains can realistically achieve, and where a rigid door remains the only defensible specification choice.

What are the key differences between a fire curtain and a fire door?

A fire curtain is a passive fire protection product consisting of a fabric or intumescent-coated textile that deploys vertically from a ceiling-mounted housing to close an opening in the event of fire. A fire door is a rigid assembly — typically steel, timber, or composite — that occupies a fixed frame and closes under spring or electromagnetic release. Both are classified under EN 13501-2, but they behave differently under fire conditions and suit different opening types.

The functional distinction matters most to architects at the specification stage. Fire doors provide mechanical resistance: they resist pressure differentials, limit smoke passage, and in burglar-resistant variants also provide physical security. Fire curtains offer spatial flexibility: they can cover very wide openings, integrate flush with a ceiling when retracted, and allow unrestricted passage when not deployed. They do not, however, provide security, weather resistance, or acoustic separation in their retracted state.

From a classification standpoint, both products can achieve EW or EI2 ratings depending on their construction and test evidence. The distinction is not inherently about which product is superior; it is about which product is appropriate for the specific opening, traffic type, and fire scenario defined in the project.

Where do building codes allow fire curtains instead of fire doors?

Fire curtains are permitted wherever a building regulation or project-specific fire safety calculation requires a fire-resistant closure in an opening, provided the curtain carries the specified classification and is installed in accordance with its test evidence. In the Netherlands, the BBL (Besluit Bouwwerken Leefomgeving, formerly Bouwbesluit) sets the absolute minimum performance requirements for fire resistance; it does not prescribe the product type. A fire curtain that meets the required classification is therefore compliant in principle. Note that the BBL sets only a minimum baseline — a heavier classification may be required depending on the specific project, sector-specific regulation (such as PGS15 for chemical storage), client requirements, or insurer requirements. Which classification applies to a given situation depends on a project-specific fire safety calculation, not on a general rule.

In practice, curtains are most commonly accepted in the following contexts:

• Large openings in logistics and production environments where roller doors or sliding doors are impractical
• Atrium separations and escalator voids where a rigid door cannot close the geometry
• Stage and theatre proscenium openings governed by specific sector regulations
• Internal openings where the curtain supplements an active suppression system as part of a performance-based fire strategy

The key constraint is always the classification report and the extent of the test evidence. A curtain approved for a specific maximum width cannot be extrapolated beyond that width without additional testing or a technical assessment. Architects specifying curtains for non-standard geometries should verify the extent of the manufacturer’s test evidence before committing to a product in the design file.

What fire resistance classifications can fire curtains achieve?

Fire curtains can achieve EW classifications and, in certain constructions, EI2 classifications under EN 13501-2. The classification system works as follows: E (integrity) means flames and hot gases are stopped; W (radiation reduction) means radiant heat transfer through the assembly is limited — this is the Dutch standard baseline criterion; I2 (insulation, less strict criterion) means the curtain additionally limits the temperature rise on the unexposed side, though a higher temperature rise is permitted compared to the stricter I1 criterion. The number that follows (30, 60, 90, 120, etc.) indicates the number of minutes of guaranteed performance during a standardised fire test per EN 13501-2.

Common classifications available in the market include EW 30, EW 60, EI2 30, and EI2 60. Whether a specific curtain product achieves EI2 depends on its construction: the fabric, the intumescent seals at the guides, and the integrity of the housing. Not all curtain systems achieve EI2, and architects should not assume that a curtain rated EW can be substituted where EI2 is required by the fire safety calculation.

One classification that fire curtains cannot achieve is EI1 — this stricter insulation criterion limits the temperature rise on the unexposed side to a lower threshold than EI2 and applies specifically to products tested under the more stringent insulation protocol. EI1 is more commonly associated with glazed fire door assemblies. If the project specification calls for EI1, a fire curtain is not an appropriate substitution without explicit confirmation from the test evidence. Always distinguish between EI1 and EI2 when specifying or reviewing a classification — never rely on a reference to “EI” alone without the suffix, as the two criteria differ significantly in what they permit.

When does a fire curtain fall short of a door’s performance?

A fire curtain falls short of a rigid fire door in four specific performance areas: physical security, smoke control in the retracted position, mechanical impact resistance, and operational reliability in environments with high air pressure differentials. Architects should evaluate each of these against the project’s actual requirements before accepting a curtain as an equivalent substitute.

Security and impact resistance

Fire curtains provide no burglar resistance and minimal resistance to accidental mechanical impact. In production environments where forklift traffic or heavy goods movement occurs near the opening, a curtain’s fabric and guide system are vulnerable to damage that would compromise both its fire resistance and its ability to deploy correctly. A rigid fire door — particularly one designed for industrial traffic conditions — provides a level of mechanical robustness that a curtain cannot match.

Smoke control and air tightness

When retracted, a fire curtain provides no smoke separation. A fire door with smoke seals provides continuous separation even before a fire event triggers deployment. Smoke resistance is tested and classified separately from fire resistance: fire resistance testing follows EN 1634-1, while smoke control testing follows EN 1634-3, with results classified per EN 13501-2. In occupancies where smoke compartmentation is required as a continuous condition — rather than only on alarm activation — a fire door is the appropriate product. Curtains are passive in the sense that they only activate on deployment; they do not provide the ambient separation that a closed door achieves.

How should architects document a fire curtain specification for permitting?

Documenting a fire curtain specification for a building permit requires the same level of evidence as any other fire-resistant closure: a CE declaration of performance, a classification report from an accredited testing body, and confirmation that the product’s test evidence covers the actual opening dimensions and installation conditions. The classification report must reference the applicable standard — EN 1634-1 for fire resistance (integrity and insulation) and EN 1634-3 for smoke control — and confirm the classification achieved per EN 13501-2.

Note that for industrial fire doors, two CE marking standards apply simultaneously: EN 16034 (covering the fire- and smoke-resisting closing function) and EN 13241 (covering the industrial door as a general product category). These are not interchangeable; both apply regardless of fire rating. Verify that the product’s CE documentation addresses both where relevant.

For permit submission, the specification file should include:

1. The required classification derived from the project’s fire safety calculation (not a generic assumption)
2. The product’s classification report confirming it meets or exceeds that requirement
3. The CE declaration of performance referencing EN 13501-2
4. Installation instructions confirming the structural fixing requirements are met by the building’s ceiling or lintel construction
5. Maintenance and inspection protocol, as curtain systems require periodic deployment testing to remain compliant

One practical advantage of working with manufacturers who publish their documentation openly is that this file can be assembled without relying on a sales process. Metacon-Next, for example, makes classification reports, CE declarations, and EPDs publicly available — a specification-stage requirement that not all manufacturers meet without a formal request.

Which applications are best suited to fire doors over fire curtains?

Fire doors are better suited than fire curtains in applications where the opening must provide continuous separation, resist mechanical impact, meet burglar resistance requirements, or serve pedestrian and emergency egress routes. These conditions describe the majority of openings in industrial and logistics buildings, which is why rigid fire doors remain the dominant product in those sectors.

Specific applications where a fire door is the more defensible specification choice include:

• Forklift and internal transport routes: The opening must withstand repeated mechanical contact. A rigid door designed for industrial traffic provides this; a curtain does not.
• Emergency exit routes: Escape doors must meet specific hardware and opening-force requirements that curtains cannot satisfy.
• Openings requiring EI1 classification: As noted above, curtains are not tested to EI1 and cannot substitute for a product that achieves this stricter insulation criterion.
• Openings where continuous smoke separation is required: A door with smoke seals provides this without relying on alarm activation.
• Openings subject to EI2 60 or EI2 90 requirements in combination with high air pressure differentials: Curtain guide systems can be compromised by sustained pressure from HVAC or industrial extraction systems.

For production halls, logistics centres, and healthcare complexes — the environments where Metacon-Next’s fire-rated industrial doors are most frequently specified — a rigid door covering the required classification is typically both the technically correct and the more straightforward choice to document for permitting. Which classification is required for a specific building depends on the project’s fire safety calculation; this is a question for a qualified fire safety engineer or the local authority, not a determination that can be made from product category alone. When the opening geometry, traffic pattern, or operational requirement makes a rigid door impractical, a fire curtain with verified test evidence for the required classification is a legitimate alternative, but the burden of proof falls on the specification, not on the product category.

If you are working through an opening specification and need to confirm whether a curtain or a rigid door is the appropriate solution for a specific classification and geometry, the team at Metacon-Next can provide technical input without requiring a commercial commitment. For projects where the specification is already defined, a quotation request will connect you with a certified dealer in your region.

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