Fire-rated dampers are an important passive fire protection measure for preventing the spread of fire and smoke through ventilation ductwork. With different types for different applications (such as motorised, mechanical, and intumescent), any fire stopping around these systems should be in accordance with the damper manufacturer’s tested firestopping details.
What is a fire-rated damper?
Purpose of fire-rated dampers in ventilation systems
You’ve probably come across the term ‘fire-rated damper’ and wondered what sets it apart from a standard damper, such as a volume control or a balancing damper, for example.
Fire-rated dampers are installed around ductwork where they pass through compartment walls and floors; being ‘fire rated’ simply means that they can resist fire for a specified time, preventing the spread of fire through air ducts.
They are typically found in a building’s HVAC (Heating, Ventilation, and Air Conditioning) system and may also be referred to as fire dampers or fire shutters.
Fire dampers come in a variety of shapes, types, and sizes, and not all are suitable for every application scenario. Therefore, it is crucial that design teams speak with the damper manufacturer early in the design process to ensure that the correct damper is selected.
How they activate during a fire
As mentioned above, fire dampers come in many forms:
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Mechanical Fire Dampers
Also known as ‘thermal fire dampers’, these devices close when the temperature reaches around 74°C, typically triggered by a fusible link that melts in response to heat, causing the blades to shut to prevent the spread of fire.
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Motorised Fire Dampers
Motorised fire dampers connect to smoke detection systems through actuators, which are motors that effectively move the damper. When the fire alarm sounds, the actuator closes the damper and prevents the spread of smoke.
- Intumescent Fire Dampers
These dampers typically have no moving parts. Instead, in the event of a fire, the graphite material of the intumescent product will expand to close the openings within the damper to prevent the fire from passing through to the adjacent compartment.
The role of fire compartmentation
Fire compartmentation is a critical element of passive fire protection, but it can only be effectively achieved when fire safety through early engagement is prioritised at the design stage of the project. It involves dividing the premises into areas of controlled risk using fire-resistant walls and floors.
Through the correct specification and installation of tested products, fire compartmentation can contain a fire to its area of origin for as long as fire tested, and provide time for the fire service to arrive, tackle the fire, and rescue residents in need. 
It’s worth noting that fire dampers are typically not the same as smoke control dampers – they both play different roles in a building’s HVAC system.
While fire dampers are mainly designed to reinstate compartmentation, smoke control dampers operate in a similar way when closed but are primarily installed to extract smoke, providing a clear route for occupants and firefighters.
What firestopping systems are approved for fire-rated dampers?
The fire-resistance test standard for fire shutters in Europe and the UK is BS EN 1366-2. This evaluates a damper’s ability to prevent the spread of fire and smoke through HVAC ductwork.
However, this standard isn’t suitable for non-mechanical fire dampers or dampers in suspended ceilings; therefore, another fire-resistance standard would be used for those applications. For example, BS EN 1366-12 for non-mechanical dampers.
What spacing rules apply to fire-rated damper penetrations?
We recommend speaking directly with the damper manufacturer to understand the requirements of their system and their specific fire test evidence.
All the Quelfire team can advise is that, because fire dampers are tested to their own standard rather than to BS EN 1366-3, the test standard for service penetrations, they must not be in the same aperture as other service types, such as cables or pipework.
The distance between apertures in supporting constructions must be at least 200mm to comply with Section 13.7 of BS EN 1366-3:
However, the flexible wall manufacturer or the structural engineer for rigid walls and floors may require a greater distance between apertures, and the largest requirement must be followed.
So, when would Quelfire’s product be used around fire-rated dampers?
Damper manufacturers have tested certain applications with their systems in which additional products, such as fire batt or mortar/compound, can be used.
Some damper manufacturers may be specific about which fire batt or mortar/compound products can be used, or they may state certain material specification requirements that conform to their damper EXAP.
For example, when it comes to fire batt, you may see the following minimum material specifications in the damper manufacturer’s detail:
- Fire batt with a minimum rock fibre density of 140kg/m³: QuelStop Fire Batt is 140kg/m³ density
- Fire batt with a minimum ‘Reaction to Fire’ rating of Class E: QuelStop Fire Batt is rated Class E
- Fire acrylic sealant that is tested to BS EN 1366-4: QuelStop Intumescent Acrylic Sealant is tested to both BS EN 1366-4 and BS EN 1366-3
When it comes to mortar or compound, you may see the following:
- Fire protection mortar tested to EN 998-2, Classes M2.5 - M20: QF2 Fire Protection Compound has been tested to EN 998-2. EN 998-2 no longer shows M ratings on certificates. However, if it were still shown, our QF2 compound would be rated M5 for compressive strength, as shown in the table below.
Frequently asked questions about fire-rated dampers
Does Quelfire have any specific fire damper solutions?
Quelfire is currently able to provide the following details based on the IFC Assessment Report, IFC PAR/23604/01:
- QuelStop Fire Batt in walls: Detail QB-FW100-D-31
- QF2 Fire Protection Compound in floors: Detail QF2-CF150-31
However, these details rely on fire test evidence from both Quelfire and Swegon, so we advise you to speak directly with Swegon for information on how to install their system and when these details are appropriate to use.
What do fire dampers look like?
Fire dampers come in various shapes, such as square, rectangular, or round, and are typically made of galvanized steel.
For an intumescent damper, instead of mechanical blades inside the design, you’ll find a highly reactive intumescent that expands when activated by heat, essentially closing off the duct and forming a plug as the service melts.
Are fire dampers a legal requirement?
Yes, fire shutters are legally required in the UK whenever ductwork passes over fire compartment boundaries. Under the Regulatory Reform (Fire Safety) Order 2005 and BS 9999:2017, building owners must test and maintain dampers at least once a year.
Who can install fire dampers?
When it comes to fire stopping, competency is critical to ensuring compliance; therefore, we would always promote competent installers with the correct Skills, Knowledge, Experience, and Behaviours – SKEB – to install, test, inspect, and maintain fire dampers to the correct level.
If you have any questions about the details above, please don’t hesitate to contact the technical team.
