What are the limitations of using PU expanding foam? Firestopping FAQs

*Polyurethane (PU) fire foam is combustible. It comes in many different colours, but the most common colour is pink, earning it the name ‘pink foam’.

There are widespread misconceptions in the industry about fire-rated PU foam, due to a poor understanding of its use and suitability.

Whilst it can sometimes be used to effectively seal small linear gaps, for instance, pink foam has a limited tested scope of application. Therefore, we strongly advise against using it when firestopping service penetrations.

It is important to understand that an ‘up to’ fire rating refers to the maximum time the product has ever achieved in a fire test, and it may have only achieved that specific fire rating in one application. That may mean that in another application, it needs to be used in a system with other firestopping products to achieve the ‘up to’ rating.

There is a danger of ‘fire-rated’ foam being perceived as a product suitable for all circumstances. For example, if it has a four-hour fire rating, then this applies to all applications.

There have been cases where pink foam has been used to firestop any leftover gaps with no second thought. However, if you check the small print of some fire foams, they require other products to be used in conjunction – for example, intumescent sealant.

When it comes to any life-safety product it is crucial to read the small print – if a piece of information seems too good to be true, then ask the appropriate questions and do your due diligence.

Ultimately, a building needs to be built using suitably tested details. Therefore, before selecting a product, it is recommended to check the relevant manufacturer’s tested scope of application.

This entails looking beyond what is stated on the packaging and the product data sheets and asking the manufacturer for the standard installation details, certification, and scope of application. You must find the tested details before the product to ensure that the selected product will work in the event of a fire.

‘Fire-rated’ foam has a limited tested scope of application. Although it is cheap and easy to apply, selecting the appropriate tested product should never be about the cost, but saving lives and protecting property.

If you have any further questions, or need help selecting the appropriate service penetration seal, then please don’t hesitate to get in touch at technical@quelfire.co.uk.