Why Intumescent Fire Protection is a Legal Requirement in the UK

If your building has structural steel, fire protection isn't optional — it's the law. Approved Document B of the Building Regulations, the Regulatory Reform (Fire Safety) Order 2005, and BS 9999 all set out clear requirements for protecting structural elements from fire. Intumescent coatings are the most widely used method of achieving compliance. Here's what you need to know.

The Problem with Unprotected Steel

Structural steel is strong, but it loses its load-bearing capacity rapidly when exposed to fire. At around 550°C — which can be reached within 5 to 10 minutes of a fully developed fire — steel retains only about 60% of its room-temperature strength. By 700°C, it has lost over half its strength and begins to deform.

This is why building regulations require structural steel to be protected. The goal is to delay the steel reaching its critical temperature for long enough to allow safe evacuation and firefighting operations. Depending on the building, this could be 30, 60, 90, or 120 minutes.

Approved Document B — The Key Regulation

Approved Document B (ADB) is the section of the Building Regulations for England and Wales that deals with fire safety. It sets out the minimum periods of fire resistance required for structural elements based on the building's purpose, height, and floor area.

The Regulatory Reform (Fire Safety) Order 2005

The Fire Safety Order applies to all non-domestic premises in England and Wales. It places a duty on the "responsible person" (usually the building owner, employer, or managing agent) to carry out a fire risk assessment and ensure that fire precautions — including passive fire protection — are adequate and maintained.

If structural fire protection has been specified and installed, it must be maintained in good condition. Damaged or deteriorating intumescent coatings must be repaired or replaced. Failure to maintain fire protection can result in enforcement action, prohibition notices, or prosecution.

Post-Grenfell: The Building Safety Act 2022

Following the Grenfell Tower tragedy, the Building Safety Act 2022 introduced stricter requirements for higher-risk buildings (residential buildings over 18 metres or 7 storeys). The Act created the Building Safety Regulator and introduced a new "gateway" approval process that scrutinises fire safety measures at design, construction, and occupation stages.

For intumescent fire protection, this means:

• Full documentation of the fire protection specification, including product data sheets, fire test evidence, and assessment reports
• Third-party certification of the installed coating (DFT testing, batch traceability)
• Golden thread of information — a complete, accessible record of all fire safety measures throughout the building's life
• Competence requirements — contractors must demonstrate they are qualified and experienced

BS 9999 and Fire Engineering Approaches

BS 9999 is the British Standard code of practice for fire safety in buildings. It provides a more flexible, risk-based approach to fire safety design compared to Approved Document B. Fire engineers can use BS 9999 to justify alternative fire protection strategies, but the fundamental requirement remains the same: structural elements must achieve the required period of fire resistance.

What Happens If You Don't Comply?

Non-compliance with fire protection requirements can have serious consequences:

• Building control rejection — the building will not receive a completion certificate without compliant fire protection
• Enforcement notices — the fire authority can issue notices requiring remedial work
• Prohibition notices — the building can be closed until fire protection is brought up to standard
• Criminal prosecution — responsible persons can face fines or imprisonment under the Fire Safety Order
• Insurance implications — insurers may refuse to cover a building without compliant fire protection
• Civil liability — in the event of a fire, inadequate fire protection could result in negligence claims

Why Choose Intumescent Coatings?

There are several methods of fire protecting structural steel — intumescent coatings, board systems, and cementitious sprays. Intumescent coatings are the most popular choice because they:

• Preserve the aesthetic appearance of exposed steelwork
• Can be applied quickly by spray application
• Are available in a range of finishes and colours
• Add minimal weight and thickness to the steel
• Can be applied on-site or off-site
• Are suitable for complex steel geometries

Certification and Documentation

A compliant intumescent coating installation should be supported by:

• Product fire test certificates (tested to BS 476 or BS EN 13381-8)
• Assessment reports for the specific steel sections and fire ratings
• DFT (dry film thickness) readings for every protected member
• Batch certificates and material traceability
• Certificate of conformity from the coating contractor
• Third-party inspection reports (where required)

At CladCoat Solutions, we provide all of this documentation as standard with every intumescent fire protection project. Our work is fully certified and compliant with current building regulations.