What you can’t see makes sure fire can’t hurt you
12 April 2018
Passive fire protection – built-in measures that protect the structure of buildings – was the subject of the opening presentation in the Fire Safety Keynote Theatre at the Fire Safety Event this morning (12 April).
First to speak was ASFP chief executive Niall Rowan, who began by explaining the two main categories of passive fire protection: structural and compartmentation. Said Niall: “Steel loses half its strength at about 500°C so, to maintain structural integrity, it needs to be insulated with various materials – coatings, casings, boards and, increasingly, reactive intumescent coatings. More relevant from the fire risk assessor’s point of view, though, is compartmentation, which is sub-dividing the building into manageable areas of risk, thus giving people a chance to get out before the fire takes hold, and providing access and protection for the Fire Service.”
He then went on to explain what passive fire protection looks like, using various images to illustrate the likes of intumescent strips, fire-resistant ducts and cable ladder systems. But the right products are no good if they haven’t been installed correctly.
Niall explained: “The issues with installation are that there is no bar to entry – anyone can set themselves up as a PFP installer – there is not enough post-installation inspection and enforcement, there’s a fixation on price instead of value, there is multiple sub-contracting, work is poorly designed and planned, and action by follow-on trades can really cause problems.”
The key requirement is to have trained, competent installers and, to this end, the ASFP offers a foundation course in passive fire protection, which, said Niall, provides essential knowledge and understanding in this specialist field.
For specifiers wishing to be sure their passive fire protection has been correctly installed, he had the following advice: “Make sure the products and installer you choose are third party-certified. The certification body will have sampled product specimens and they use the evidence to create a scope of certification. Installers will have had their company procedures audited, their work rigorously inspected and their competence assessed, and will hold a certificate confirming what they are certified to install. Such installers will also be listed on the certification body’s website.”
Niall then handed over to David Lamb, of FSi, who spoke about firestopping systems and where to find them. “They’re generally in the areas you don’t see,” David explained, “such as behind ceilings and walls, and under floors. There are essentially three categories: penetration seals, linear-gap seals and cavity barriers.”
David then provided a useful run-through of the criteria to bear in mind when specifying fire-stopping measures:
- What is the fire-resistance requirement for the project (e.g. 30/60/90/120 minutes’ integrity)
- What standards are you working to – BS or EN?
- What is the building-assembly type – are you working to a floor or a wall?
- What is the construction element – flexible partition walls, concrete, wood-frame, block?
- What are the penetrating items – plastic or metal pipes, cables, etc.
- What are the specifics of the services – diameter of the pipes/cables, type of plastics, type and thickness of insulation, etc.
“The key,” said David, “is to understand what you have so you can decide what you need.”
He then ran through the various types of penetration sealing systems available, including batt and sealant penetration seals, fire-rated sealant, fire-rated structural compounds, pipe collars and wraps, pillows, electrical putty and putty pads, compressible linear-gap seals, flexible coating systems and cavity barriers.
David concluded: “Understand your requirements and the substrates you are working in. Products should be tested and certified, and installed by third party-certified installers. Finally, keep records of where and what you’ve had done, and by whom.”
FSi has a range of technical handbooks available, as well as a PFP app for mobile phones. For more information, visit www.fsiltd.com