Nov 21, 2019 Last Updated 10:52 AM, Aug 14, 2019

How fire-rated, closed-cell materials can insulate and create a firestop to achieve reliable protection

Published in Product Innovation
Rate this item
(0 votes)
Tagged under

Here Anthony Barnett, Technical Marketing Manager at Armacell UK, looks at how fire-rated, closed-cell materials can both insulate and create a firestop to achieve reliable protection on pipework through walls and ceilings without the need for additional firestop measures.


The speed at which fire can spread means that minutes can make all the difference to building occupants. It’s one of the reasons why there are mandatory requirements for firestopping and fire compartments. To put this into context, the annual number of fatalities from fire-related incidents in the UK from July 2016 to June 2017 was 346. These figures would potentially have been higher without firestopping measures to delay the speed in which the fire spread.

Firestopping involves sub-dividing the building into a number of discreet compartments using fire-rated walls and ceilings in order to prevent the passage of fire and smoke from one cell to another. This is a requirement set out in Building Regulations’ Approved Document B. The primary role of a fire compartment is to protect the means of escape for a given amount of time; typically 30, 60, 90 or 120 minutes.

As buildings become larger or more complex, ensuring the integrity of these compartments can potentially be a matter of life and death for the occupants. High-rise residential and commercial buildings are a good example of where reliance is placed on fire compartmentation, and it is common for each apartment, floor or unit to be treated as its own 'cell'. However, as these buildings are refurbished, the original compartments can be compromised, for example, when new IT or HVAC services pass through them.

Fire compartments

Passive fire protection systems effectively compartmentalise a building by creating fire-resistant walls, floors and ceilings. It is the integrity of these compartments that the occupants rely on when they are making an emergency evacuation, as well as allowing access for rescue services to tackle the blaze. If any apertures are not sealed or have inadequate sealing it can allow the fire to spread quickly into escape routes such as stairwells and corridors, hindering or blocking the exit.

Recent developments in the industry, for example, ArmaFlex Protect, can be specified on building services pipework passing through fire-rated walls and ceilings to provide both thermal insulation and firestopping. Choosing a closed-cell insulation with intumescent properties and sealing the gaps around the aperture is an effective way of ensuring the integrity of the compartment. It also means that pipework achieves the required level of energy efficiency and condensation control along its entire length.

The insulation provides firestop protection for penetrations on both non-combustible and combustible pipes in ceilings, solid walls or lightweight walls. The intumescent material expands to 20 times its initial volume in the event of a fire and is fire resistant up to EI 120. The closed-cell material properties ensure thermal insulation and reliable condensation control along the entire length of the pipe (when sealed to adjoining lengths of pipe insulation).

It is important to have a system-based approach when it comes to the integrity of fire compartments, which extends to a sealing mortar for the annular gap and fire collars. Our non-combustible firestop mortar has a melting point of >1000°C and not only ensures reliable and effective fire protection, but further helps to protect pipes against heat losses and prevents noise being transmitted to adjoining structural elements.

Fire collars are an effective part of a firestopping system approach too and are suitable for fire penetration seals around plastic pipes with or without fire-rated, closed-cell insulation. The steel collars are lined with an intumescent material that expands in a fire, forming a lasting hermetic seal. The pipe collar can be used for sealing single or multiple combustible pipes and multi-use plastic beverage tubes (pythons) in refrigeration, air conditioning and hot and cold water applications. Collars such as this are easy to install, being simply laid around the pipe that is to be sealed before being fixed in place.

Buying time

Fire compartmentation is a vital part of building design, and the parts that can’t be seen are just as important, such as correct sealing of apertures hidden behind walls and ceilings. A common reason why fire compartments fail is because these apertures, for HVAC or IT services, are not correctly sealed. In an unfortunate number of cases, it is because they fall into the ‘out of sight, out of mind’ category. However, choosing closed-cell materials that both insulate the pipe and provide a firestop offer a simple solution.

Login to post comments

Most Read

Magply Boards Carry K-Rend Finish to Complete Exclusive Surrey Housing Developement

Magply Boards Carry K-Rend Finish t…

17 Jun 2019 Roofing, Cladding & Insulation

Magply Boards Cover Superfast Steel Framing System

Magply Boards Cover Superfast Steel…

17 Jun 2019 Roofing, Cladding & Insulation

Three is the magic number for new modular housing scheme

Three is the magic number for new m…

17 Jun 2019 Roofing, Cladding & Insulation

Promoting fire safety in the public sector at FIREX International 2019

Promoting fire safety in the public…

17 Jun 2019 Product Innovation

Housing 2019 addresses industry challenges

Housing 2019 addresses industry cha…

17 Jun 2019 Product Innovation

Find us on Facebook