How should you firestop a fire-rated duct or damper? Tested Detail Queries

Fire-rated metal ducts and dampers are tested to a different fire-resistance test standard than other service penetrations (which are tested to BSEN1366-3) and should therefore be:

  • in a separate opening, sufficiently spaced and in line with the fire compartmentation;
  • and firestopped in accordance with the duct or damper manufacturer’s recommendations/test evidence.


In accordance with BSEN13501-2, a duct or damper penetration should be a minimum of 200mm away from penetrations or elements tested to a different standard (e.g., doors or pipes and cables etc). The spacing of the penetrations should also take into account the supporting construction manufacturer’s requirements for spacing between apertures, which may be more than 200mm.


We always advise that you speak to the metal duct/ damper manufacturer directly to ensure that you install their system in accordance with their fire test evidence.

We are aware that some manufacturers permit a material specification and potentially suggest the use of:

  • fire batt with a minimum density of 140kg/m3 (we can confirm that QuelStop Fire Batt is 140kg/m³);
  • and intumescent acrylic sealant that is tested to BS EN 1366-4 (QuelStop Intumescent Sealant is tested to BS EN 1366-4 and BS EN 1366-3).

Therefore, our products may be suitable for the application, but the first point of enquiry must always be the duct or damper manufacturer.

The use of a fire protection compound in floor seals may also be permitted and whilst we do have some test evidence for these seals using our QF2 Fire Protection Compound, it is limited to the specific scenarios we have tested. So again, the first point of enquiry should be the duct or damper manufacturer.

If no specific details are available, then you could consider a technical assessment which should be carried out by a suitably qualified person/fire engineer and based on any available primary test data.

Quelfire are currently able to offer two standard details based on IFC assessment report IFC PAR/23604/01 as follows:

We are, of course, happy to provide any relevant test data directly to the person nominated to carry out the assessment; all requests should be sent direct to

Craig Wells

This question was answered by Craig Wells

Sales Director

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