Different types of fire protecting structural steelwork and their uses

Steel structures can suffer from the heat in a situation where there is a fire. Preserving and protecting those structures for as long as possible can help to sustain the integrity of the building and give occupants longer to escape. There are a range of options for protecting structural steelwork, from non-reactive choices such as boards and sprays, to reactive options that include thin film intumescent coatings.

Options for protecting structural steelwork from fire


Boards provide a simple way to add protection to structural steelwork via a dry process that won’t impact heavily on other activities. These boards can be lightweight or heavyweight and are factory produced, which means that thickness can be guaranteed. Boards are widely used in the UK, both where the fire protection is visible and where it is hidden.


Spray protection is a very flexible option and is not limited by the application of physical material. It is not that widely used in the UK but has a number of advantages, including its versatility and the fact that the thickness of application does not impact on the cost (which is mostly based on application labour).

Concrete encasement

Concrete is one of the most traditionally applied materials for fire protection. It has been the option of choice for ensuring structural steelwork is fire-secure since the 1970s. Many lighter and more cost effective options may be more appropriate today, but concrete encasement can still be useful. Although concrete is heavy, it is also incredibly durable and much more able to resist abrasion, damage or the impact of heavy weather. That’s why it’s often used in locations such as car parks.

Intumescent Coatings

Applied in the same way as paint, intumescent coatings are activated when temperatures reach 200-250°C. When the environment around it reaches this temperature the coating will grow to create an increased layer of low conductivity char. Intumescent coatings have been found to be incredibly effective fire protection and are available in a number of different forms. Thin coatings are usually comprised of a primer, a basecoat and a sealer coat – they are ideal in buildings where the fire requirements are up to 90 minutes. They can be applied off-site or on-site. Thick coatings have a higher dry film thickness than thin coatings and were originally created for use with hydrocarbon fires.

Partial protection options

Tests have shown that partial protection can increase fire resistance by between 30 and 60 minutes. There are a number of options for partial fire protection, including block infilled columns, web infilled columns or shelf angle floor beams, for example.

We are specialists in all forms of passive fire protection and can provide the best options in terms of cost and effectiveness. If you’d like to ensure fire protection for the structural steelwork in your building we can help – contact our specialists to discuss your requirements today.

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About Us

Hillmoore Fire Protection Limited are specialist contractors for all forms of passive fire protection. The ethos and aim of Hillmoore is to provide our clients with an un-rivalled service for the Design, Supply and Installation of all passive fire protection requirements, be it within a new build, refurbishment or upgrading project, or as part of the change of use of a property.