Fire dampers are easy to forget. They sit out of sight inside ductwork, above ceilings and behind walls, and they do nothing at all until there’s a fire. Then they have one job: to close and stop fire and smoke spreading through the building’s ducts.
A damper that’s jammed with dust, stuck with grease or rusted open can’t do that job. That’s why they need regular testing. This guide explains what fire dampers are, how drop testing works, how often BESA says they should be tested, the faults testing finds and what records you should keep.
What a fire damper does
Buildings are split into fire compartments by fire-resisting walls and floors. Every time a duct passes through one of those walls or floors, it makes a hole in the compartment. A fire damper fills that hole when it matters.
Most mechanical fire dampers have a blade or curtain held open by a fusible link. When the link reaches a set temperature it melts, and the blade drops or springs shut to close the duct. Some are spring-operated, so the spring pulls the blade closed when the link fails.
Smoke dampers are different. They are motorised and controlled by the fire alarm or building management system, and they’re tested through their controls. Our guide to fire dampers vs smoke dampers explains the difference, and our smoke damper testing page covers those.
How often fire dampers should be tested
BESA’s guide to fire damper testing requirements says all fire dampers should be tested by a competent person when they’re installed and at least annually after that. Spring-operated dampers need annual testing as a minimum.
Some sites test more often. Dampers in dusty, damp or greasy environments, such as kitchen extract systems, are more likely to fail, so a shorter cycle may be sensible. Your fire risk assessment should say what’s right for your building.
How a drop test works
A drop test proves the damper will close fully when its link fails. In outline:
- The technician finds the damper and opens the access panel next to it.
- The damper is inspected for dirt, damage and corrosion.
- The fusible link is released so the blade drops.
- The technician checks that it closes fully and seals the duct.
- The blade is reset, the link refitted or replaced, and the damper left open and working.
- The result is recorded, usually with photos of the damper open and closed.
Each damper should have a unique reference so results can be compared year on year.
Common faults testing finds
BESA notes that dust, grease and corrosion from water or condensation can all stop a damper closing. The faults we see most often are:
- blades held open by a build-up of dust or grease;
- corroded runners or springs;
- damaged or missing fusible links;
- blades that stick partway and don’t seal;
- dampers that can’t be tested because there’s no access panel.
A damper that fails its test should be cleaned, repaired or replaced. Our fire damper repairs page covers remedial work.
Need it done? Duct Doctor cleans and tests kitchen extract and ventilation systems across London and the South East, with a certificate and photo report after every clean. Get a fixed quote.
No access panel, no test
A damper you can’t reach is a damper you can’t test. In many buildings, ceilings have been fitted, walls boxed in or plant added since the dampers went in, and the access panels have been lost or covered.
If a damper can’t be reached, it should be recorded as not tested, with the reason. That’s not a pass. The fix is usually a new access panel in the duct and, where needed, a hatch in the ceiling or wall. See access panel installation.
Who is responsible
BESA’s guide says the Responsible Person has a legal duty to keep fire safety systems, including dampers, in working order. That person may be the employer, owner, landlord, facilities manager or managing agent, depending on the building.
The duty comes from the Regulatory Reform (Fire Safety) Order 2005, which requires fire safety equipment and devices provided for people’s safety to be kept in efficient working order and good repair. GOV.UK’s guide to workplace fire safety responsibilities explains who counts as the responsible person. Our guide to the responsible person goes further.
Records you should keep
A fire damper test report should give you, for each damper:
- a unique reference and its location;
- the type and size of damper;
- the test date and the technician;
- pass, fail or not accessible, with the reason;
- photos, ideally open and closed;
- any remedial work recommended.
Keep these with your fire risk assessment and building maintenance records. A fire officer, insurer or new building owner may ask for them.
Planning a testing programme
In a large building with dozens or hundreds of dampers, testing works best as a planned programme. Start with an asset register: a list of every damper, its reference and its location, ideally marked on drawings. If you don’t have one, the first round of testing can build it.
Testing can then be spread through the year or done in one visit, depending on how the building is used. Hospitals, schools and offices often prefer evenings, weekends or holidays so areas can be closed off safely. Repeat failures in one area are worth looking into, because they usually point to a cause such as damp, grease or poor access.
Kitchen extracts and fire dampers
Kitchen extract ductwork is a special case. Grease is a fire risk in its own right and it can also gum up any damper in the system. Where kitchen extract ducts pass through compartment walls, the design should follow the relevant specifications for grease-laden systems; ask a competent designer if you’re not sure what’s fitted in yours.
Duct Doctor tests fire dampers on their own or alongside kitchen extract and ventilation cleaning, which often makes sense because the access panels are already open. See our fire damper testing service or ask us for a quote.
Quick answers
How often should fire dampers be tested?
BESA says all fire dampers should be tested on installation and at least annually after that, with spring-operated dampers tested at least once a year.
What is a fire damper drop test?
The fusible link is released so the blade drops. The technician checks it closes fully, then resets it and records the result with photos.
Who is responsible for fire damper testing?
The Responsible Person under the Fire Safety Order 2005: usually the employer, owner, landlord, facilities manager or managing agent.
What happens if a damper fails?
It should be cleaned, repaired or replaced, then retested. The failure and the remedial work should both be recorded.
Are smoke dampers tested the same way?
No. Smoke dampers are motorised and are tested through their controls, usually linked to the fire alarm or building management system.
Related services
More advice
- Fire Damper vs Smoke Damper: The Difference
- The Responsible Person Under the Fire Safety Order
- Duct Access Panels: Why They Matter for TR19
- TR19 Air Explained: Ventilation Hygiene for Buildings
- All advice
This guide is general information. It isn’t legal or insurance advice: check your own policy wording and lease, and speak to a qualified adviser about your fire risk assessment.