Fire Stopping

Explore our frequently asked questions on our fire stopping products here...

Can plastic pipes that are less than 40mm in diameter be fire stopped without a closing device?

The general consensus within the industry appears to be that combustible pipes & conduits with an Internal diameter of less than 40mm only requires to be fire stopped “up to”, with no requirement for a closer device. Nullifire view the statement within Approved Document B (ADB) quite differently. Pipes with an internal diameter of less than 40mm connected to a waste outlet system are only required to be Fire-stopped up to. This in no way defines conduits for example. Regardless of the correct interpretation, we recommend the advice within ADB relating to 40mm combustible pipes be disregarded. A single 40mm pipe under fire conditions will allow a considerable amount of smoke passage through a Fire Compartment. ADB also fails to define an acceptable maximum number of such pipes per compartment breach.

There is a fire damper in the same openings as other services, how can this be fire stopped?

As ducts and dampers are tested to a different standard to cables, pipes etc. they should therefore be separated from other services and installed into their own openings. First port of call should be to contact the duct or damper manufacturers, as their tested solutions would supersede our advice. In the absence of this, or if a combined seal is evident (different services types from multiple BS-EN testing standards, through a single opening in a compartment), we can offer engineering judgements only. Test evidence/install details from the damper manufacturer will be required to assist in the creation of an engineering judgement.

Can you overcoat FS702 Intumastic?

FS702 Intumastic once fully cured may be overcoated with any standard trade emulsion or gloss to achieve a specific colour finish. Top tips for overcoating FS702: (1) Ensure the surface is free from dust and grease that may have stelled during the curing process prior to overcoating (2) You can lightly sand and file FS702 Intumastic with proprietary fillers without negating its fire performance – if required. (3) Due to the formulation of FS702 Intumastic, it is likely to require more overcoats to achieve your desired RAL colour. Always carry out a sample area before commencing with your entire project. Please ensure that manufacturer instructions are always followed, and technical consultation is carried out for specialist paints (chlorinated rubbers and alike) for confirmation of compatibility. For more information on FS702 Intumastic, please contact us.

How far from a compartment wall should my services be supported?

Services should be supported in line with the installer and/or service manufacturers recommendations. Any deviation from this may result in warranty and liability changes. It is generally assumed that services should be supported as per fire test, typically between 200mm and 500mm away from the compartment. We do not support this opinion as many service support systems are designed to accomodate thermal expansion, movement, acoustic enhancements etc. Additionally, we are not quailified to interfere with a service manufacturers specific design.