What are intumescent fire pillows? Product Information

Intumescent fire pillows are passive fire protection products designed to prevent the spread of fire through metal cable trunking systems that pass through fire compartment walls. They consist of a fabric casing filled with intumescent and organic filler materials. And yes, it would be right to assume that the name fire pillow comes from looking something like a pillow…

Fire pillows are typically used in conjunction with other firestopping measures, such as fire-rated walls or floors, to maintain the integrity of fire compartments in buildings.

How do fire pillows work in the event of a fire?

In the case of fire pillows, compared to other intumescent products, there is already a gap without the services melting. This is because the cables don’t always fill the entire width of the trunking, therefore, the gap needs to be filled with fire pillows.

When exposed to fire, the intumescent material inside the fire pillow reacts to the heat exposure and causes a reaction. This reaction causes the material to expand rapidly, increasing in volume whilst simultaneously decreasing in density.

The expansion of the intumescent material essentially plugs the gap left behind by the melted services and works to block the passage of fire and smoke, limiting the fire’s spread to other areas.

This ensures the fire is contained to its area of origin for as long as possible – known as fire compartmentation.

What properties do fire pillows have?

Fire pillows possess several important properties that make them effective in preventing the spread of fire:

Fire resistance: Fire pillows are designed to withstand high temperatures and flames. Like other service penetration sealing solutions, they have a fire rating that indicates the amount of time they can provide fire resistance.

Flexibility: They can be compressed and adapted for easy installation. Because of the different sizes available, gaps of various shapes and sizes can be filled with them, ensuring a snug fit and effective fire containment.

Reusability: Fire pillows are typically reusable and can be easily removed and replaced when necessary, such as during maintenance or when additional services need to be added to the cable trunking.

Compatibility: They can be used in conjunction with other firestopping products and systems, if fire tested together, to provide complete fire protection.


Fire pillows come in a variety of different sizes and should be chosen wisely when installed, ensuring that the trunking can be fully sealed even when there is a varying number of cables.

The cables should not take up more than 60% of the available space inside the trunking and the fire pillows should be installed lengthways, centrally positioned within the wall whilst filling the remaining space.

It is important to know that specific properties and performance characteristics of intumescent fire pillows may change depending on the manufacturer. Therefore, it is strongly recommended to utilise the relevant manufacturer’s guidance and check their tested scope of application when selecting and installing fire pillows.

QFP QuelStop Intumescent Fire Pillows from Quelfire

Learn more about the features and benefits of our QFP QuelStop Intumescent Fire Pillows.

Glenn Hutchins

This question was answered by Glenn Hutchins

Business Development Manager

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