BS EN 1366-2:2015 Fire Dampers

BS EN 1366-2:2015 specifies a fire-resistance test method for fire dampers installed in fire-separating elements. It evaluates the complete damper installation, not only the damper casing or blades.

What the test considers

• The fire damper, installation frame and applicable perimeter sealing system.
• The supporting construction, such as the tested wall or floor arrangement.
• Whether the damper is installed within, on the face of or remote from the supporting construction.
• Damper orientation and, where relevant, blade-spindle orientation.
• Closure from the open position under fire-test conditions.
• Integrity, insulation where claimed, and leakage through the closed damper installation.
• Applications with ducting on both sides, one side or neither side where suitable evidence is required.

Important limits

The standard is not intended for fire dampers installed in suspended ceilings. It is also not the test method for non-mechanical fire barriers used in ventilation ductwork; those are addressed separately by EN 1366-12.

A successful test does not create unrestricted approval for every wall, floor, size, orientation, installation position or sealing method. The classification report, permitted field of application and manufacturer’s installation instructions must be checked before specifying or changing an installation.

Selecting a damper for the wall and application

A damper should not be selected from its nominal size and headline fire rating alone. DuctFix can help review the intended application and narrow the suitable damper type, but the final selection and installation must satisfy the project fire strategy, specification, approval requirements and the product’s classification and installation evidence.

• Function: fire damper, fire-and-smoke damper or smoke-control damper.
• Supporting construction: the exact wall or floor type, thickness and fire resistance.
• Installation position: within the opening, face-mounted or remote from the separating element.
• Permitted dimensions and orientation: including blade or spindle orientation where relevant.
• Spacing and location: minimum separation between dampers and from construction edges, where defined by the applicable evidence.
• Installation details: frame, fixing, perimeter seal, duct connections, supports, actuator, controls and maintenance access.

In-wall, face-mounted and remote installations are not automatically interchangeable. Minimum separation distances are also not one universal value: they must be taken from the evidence and instructions for the proposed damper and supporting construction.

Submit the wall or floor construction, opening, required classification and proposed damper arrangement for an initial project review.

Approved Document B considerations in England

Approved Document B describes fire dampers as one of several possible methods for maintaining the performance of a fire-separating element where air-handling ductwork passes through it. It says fire and fire-and-smoke dampers should be securely fixed, located within the thickness of the fire-separating element and positioned so duct expansion would not push the damper through the construction.

• Fire dampers should conform to BS EN 15650 and have at least E 60 performance, or match the integrity period of the fire-resisting element where that is higher.
• Fire-and-smoke dampers should conform to BS EN 15650 and have at least ES 60 performance, or match the integrity period of the fire-resisting element where that is higher.
• Where smoke control is required, the detector, release mechanism, controls and cause-and-effect arrangement form part of the project design.

Approved documents give one recognised route to meeting the Building Regulations in common situations; they do not remove the need to assess the particular building, system and fire strategy.

Access, inspection and maintenance

Access to the damper and its actuating mechanism should be provided for inspection, testing and maintenance. BESA DW145:2024 recommends unobstructed access that permits observation, testing, resetting, commissioning, cleaning and maintenance, including access from both sides of the fire-separating barrier where the installation requires it. The arrangement must remain usable after ceilings and other services are complete.

• Coordinate access panels with ceilings, walls, pipework and cable trays.
• Keep the opening large enough for the intended inspection and test activity.
• Record damper and access locations on the as-installed drawings.
• Define who will inspect, functionally test and maintain the damper.
• Do not treat the presence of an access hatch as evidence that the damper installation complies.

See our Access Doors and Maintainability guide for the wider ductwork considerations.

Kitchen extract is an important exception

Conventional thermally activated fire dampers and automatically activated fire-and-smoke dampers should not be assumed suitable for kitchen extract ductwork. Approved Document B states that these methods should not be used for extract ductwork serving kitchens because grease build-up can adversely affect dampers.

Where kitchen extract ductwork crosses a fire-separating element, the proposed solution normally requires review of a suitable fire-resisting enclosure or a tested fire-resisting ductwork system, together with the current kitchen ventilation and grease-cleaning guidance.

Do not confuse three damper functions

• Fire damper: protects a fire-separating penetration in ventilation ductwork and is tested using BS EN 1366-2.
• Fire-and-smoke damper: adds smoke-leakage performance and normally forms part of a smoke-detection and control arrangement.
• Smoke-control damper: is an active component of a smoke-control system and follows the separate BS EN 1366-10 and BS EN 12101-8 route.

Design and record the installation before work starts

The project information should connect each damper asset reference to the required classification, wall or floor construction, installation method, penetration detail, controls and access arrangement. The design should also identify the damper support method and the permitted position of the first duct support on both sides. Unresolved site differences should be referred back to the system designer rather than improvised during installation.

Evidence to check on a project

1. Function: establish whether the project needs a fire damper, fire-and-smoke damper or smoke-control damper.
2. Product identification: confirm the proposed damper matches the tested and classified product.
3. Classification: check the required integrity, insulation and smoke-leakage performance.
4. Supporting construction: verify the wall or floor type, thickness and construction.
5. Installation position: establish whether the damper is within, face-mounted or remote from the separating element.
6. Orientation and size: verify the proposed dimensions and orientation are covered.
7. Penetration and sealing: follow the tested frame, fixing and perimeter fire-stopping details.
8. Duct and supports: check connections, clearances, expansion and supports.
9. Actuation and access: allow for the correct release mechanism, inspection, functional testing and maintenance.

Inspection, testing and the Golden Thread

Handover and maintenance records should include a damper inventory, unique asset identification, precise location, inspection or test date, competent operative, operational result, defects, inaccessible assets, corrective actions and relevant before-and-after photographs. As-installed drawings should be updated where provided.

Inspection and functional-testing frequency must be established from the current applicable legislation and standards, the manufacturer’s instructions, the building fire-risk assessment and the environmental conditions. Older guidance should not be used to justify an extended interval without checking the current requirements.

Classification is a separate step

BS EN 1366-2 provides the fire-test method. The resulting performance is classified using the applicable classification standard and supporting product documentation. Review the classification report and permitted field of application rather than relying only on a product label or headline fire-resistance period.

Source basis: BS EN 1366-2:2015, Approved Document B Volume 2 for England, BESA DW145 Second Edition (November 2024), BESA TB/001 Fire and Smoke Damper Maintenance (January 2016, used only as supporting historical guidance) and BESA TR19 Air, Second Edition 2026, for access and maintenance context. This is an original practical summary and does not reproduce or replace the current standards, classification reports, manufacturer instructions, fire strategy, maintenance requirements or competent professional advice.