Compliant passive fire protection encompasses the entire infrastructure of a building. Rooms, floors, and communal areas are all interlinked by a complex network of installations, which need to be incorporated into any fire protection strategy.
A standout example of this is the use of compartmentation and fire-stopping to prevent the spread of fire through pipes.
Compartmentation
Compartmentation involves dividing buildings into a series of compartments, which are then reinforced with fire-stopping solutions to contain the passage of flames and smoke.
However, it’s possible that these compartments can be breached by ‘service penetrations’, which is when new systems such as wires, ducts, and pipes are installed in a way that creates gaps that smoke and fire can seep through.
fire-stopping of pipes
It’s possible to install pipes and other infrastructure elements in such a way that buildings remain safe
If compartments have air leakages or heat is conducted from one compartment to another through service penetrations, passive fire protection could be compromised.
However, it’s possible to install pipes and other infrastructure elements in such a way that buildings remain safe provided the correct measures are taken. In this article, CLM takes a closer look at the fire-stopping of pipes through walls within passive fire protection.
How do fires spread through metal pipes?
Plastic piping can catch fire fairly easily, but even metal pipes can start fires in compartments adjacent to the original point of ignition. Unprotected pipes conduct heat, therefore if they pass through compartments they represent a dangerous breach. Even the slightest contact between superheated metal and combustible material could cause a fire to spread.
If there are gaps around the outside of the pipework, there are further complications. Radiation, convection, and even direct contact with flames could add to ways in which a simple metal pipe can turn into a dangerous fire hazard. But that does not mean that services such as pipes cannot pass through the fireproof compartments that protect buildings from fire. If the right precautions are taken, they can be perfectly safe.
apply fire-stopping to pipes through walls
Fire-stopping materials are specifically designed to expand when exposed to heat, sealing the spaces
Penetration seals for services passing through fire-resistant compartments are essential for maintaining the integrity of compartmentation. Acrylic seals prevent air leakage, and with that, limit the spread of smoke and flames.
Fire sleeves, pipe collars, and other fire-stopping materials are specifically designed to expand when exposed to heat, sealing the spaces between pipes and the materials around them.
Choice of component
When the pipes are made of plastic, they can crush the pipes, fully sealing off any gap that can accelerate the spread of fire. The choice of components depends on the circumstances and the building materials used.
For example, fire-stopping around copper pipes differs from fire-stopping measures for plastic pipes, but the goals remain the same. Fire stopping aims to block airflow and insulate the pipes so that they can’t ignite fires in adjacent compartments.
How to apply fire-stopping around pipes
A variety of tools and installations can be used to properly seal pipes, as part of a fully compliant fire-stopping and compartmentation strategy:
- Fire sleeves or fire wraps fill the gaps created when installing pipes. They protect pipes that pass through fire-rated walls and floors and fit over the pipes without the need for mechanical fasteners. They are made from intumescent materials, covered with a polyethylene sleeve, and work similarly to fire collars but they can only be used when installed inside solid materials such as concrete.
- Fire collars are made from metal lined with intumescent material that will expand quickly when exposed to heat, sealing off any gaps around pipes. They fulfill a similar function to pipe sleeves but are installed using mechanical fasteners attached to the wall, floor, or partitioning.
- Fire pillows can be used to permanently seal off larger surface penetrations or act as a temporary solution when service installations require regular replacements. Much like fire collars, they are also made from intumescent materials, swelling when exposed to heat to seal any gaps that flames and smoke could pass through.
- Special fire sealants and gap fillers can also play a role in fire-stopping smaller gaps around pipes, depending on the specific requirements outlined by the manufacturer. The choice of sealant depends on the substrates they will be in contact with.
fire-stopping solution survey
Although many of these materials and solutions are readily available, fire-stopping solutions around pipes and other service penetrations should always be implemented by a certified passive fire protection specialist.
CLM team of specialists conducts compartmentation surveys which involve inspecting pipes and other service penetrations, and in the past, they have identified incorrect or non-compliant fire-stopping solutions that can exacerbate existing structural fire risks.
