Stop the spread

A service penetration through a fire separating element may well be viewed as a minor element of a compartment wall or floor, but the significance of such penetrations cannot be emphasised enough. This article will cover mechanical and electrical (M&E) service penetrations in buildings, the principal design considerations for this critically important fire safety element, and the importance of independent third party certification (TPC) and technical evaluations.

Firestopping has historically been considered an activity that can be undertaken by those carrying out the installation on site. As a result, very little consideration has been given to firestopping of service penetrations during the design stage. The problem with this approach is that it makes it very difficult or even impossible to install manufacturer tested and approved firestopping solutions, as there is often insufficient space available.

Dampers, pipes and cables are sometimes installed within the same penetration despite there being no approved test method for that scenario. In addition, there are cases of deviations from tested and approved manufacturer details at critical interfaces, such as where services emanate from risers. Another challenge is that there can be a misunderstanding as to ‘who does what?’, as firestopping design and installation includes roles and responsibilities which are not sufficiently considered and allocated.

Generally, these issues occur as a result of a lack of consideration of passive firestopping, a lack of clarity on roles and responsibilities between specialist trades and a lack of ownership.

Early involvement

In order to get firestopping right, the industry needs to look at incorporating standard solutions. This means that the firestopping of service penetrations needs to be considered when the building is being spatially planned and the building services systems are being designed and coordinated. The primary objective is to ensure that third party tested and approved, standard firestopping solutions are incorporated into the design.

It is likely that specialist subcontractors and firestopping manufacturers will need to be engaged earlier than they have been traditionally. Everyone involved in the design and construction stage should also read and understand the fire strategy, which is prepared by a suitably qualified and experienced fire engineer and provides details of compartmentation and the requirements for any passive fire protection.

The section of the fire strategy covering  penetration seals should be read and understood by the designer, contractor, installers and inspectors of the penetration seals, to ensure that they are designed and installed compliantly.

Design considerations

Best practice in ensuring that standard tested and approved firestopping details are incorporated at the design and coordination stage, is to check that the builder’s work penetrations are sized and then subsequently positioned using spacing rules developed from tested and approved details. These spacing rules should include factors such as pipe diameters, insulation thicknesses and edge distances.

Doing this will ensure that builder’s work penetrations are not under or oversized, and will make it easier for the firestopping contractor to seal the penetration in accordance with the tested and approved detail. Maintaining the fire resistance ratings of these compartment elements is essential and site managers should be especially conscious of where voids and penetrations from building services installations bypass compartment lines.

Collaborative approach

To ensure the best chance of success, service penetrations should be considered collaboratively at the design stage, with input from the M&E designer, the architect and ideally the partition contractor and firestopping specialist. There are usually several parties involved in the installation of service penetrations and it is important that all those who carry out installation are competent to
do so.

However, the really important message is that firestopping of the penetration seal should be carried out by a third party accredited firestopping specialist. It should not be left to the M&E contractor, as they may not have the competence to take on that responsibility. Whenever someone is specifying firestopping products, it is important that they specify a third party tested product.

In short, this means that the product has been independently tested by a UKAS accredited laboratory with a declaration of performance or other performance rating that has been independently verified. The alternative is that someone has tested it themselves. In such cases there are no assurances of reliability and safety. A second part of this is that the contractors who are employed to carry out the firestopping should be third party certificated as specialists to carry out that particular work.

Furthermore, responsibility does not end following design, supply, installation or even building handover. Once the building is occupied, regular and effective maintenance is essential, to ensure that penetration seals and other firestopping solutions are properly maintained.

There are three ways that the industry appears to work in respect of technical evaluation. The worst case scenario is self declaration, whereby a manufacturer might say that its product is tested to a certain standard. However, there is no guarantee that the product will actually have reached that correct standard so, in this case, the specifier is simply relying on the manufacturer’s advice or word.

In a second scenario, the manufacturer has a test report stating that its product was tested in accordance with ‘x, y and z’, and that they have a certificate. This however raises questions as to whether or not the test sample was actually representative of what is being installed on site. The product test is not installation specific and there may be design changes.

TPC is the best case scenario, as that ensures product conformity, as well as a full audit of the company involved in the manufacturing of the product. This will provide the specifier, customer and end user with the confidence that the product has been tested fully in accordance with the latest British Standards and is fit for purpose.

The Association for Specialist Fire Protection (ASFP) offers guidance on the necessary qualification levels for those who carry out technical evaluations, and the Passive Fire Protection Forum provides similar guidance on the processes and relevant experience required for assessments, much of which will also be relevant to the manufacturer’s own evaluation process. In summary, the guidance is as follows:

  • passive firestopping of service penetrations must be considered during the design stage
  • wherever possible, tested and approved standard solutions must be incorporated
  • engage early with the main contractor and project team to ensure a consistent approach
  • roles and responsibilities for passive firestopping should be defined from the outset
  • engage with preferred manufacturers early
  • develop benchmark and sample areas
  • do not leave it to others to come up with solutions

A new best practice guide, Firestopping of Service Penetrations: Best Practice in Design and Installation, has been produced collaboratively by five leading not for profit organisations representing the wider construction and fire safety industries. It provides guidance to enable project teams to meet their obligations to deliver a safe and secure project in terms of penetration seals.

The number one goal is to ensure fire safety in performance, both now and in the future. It is a conversation that should take place between all parties including the manufacturer, architect, specialist installer, fire engineer and M&E consultant. Everyone involved in the provision of a fire protection package, at any level, shares liability for its effectiveness and performance when needed in a fire. If properly designed, effective compartmentation is a major measure to protect life safety and buildings.