Fire Protective Boarding & Encasement of Structural Steel

Fire Protective Boarding & Encasement of Structural Steel

Some steel cannot be sprayed.

Fire protective boarding and encasement is the method used where intumescent coatings are unsuitable, impractical, or incompatible with the building design. It provides a robust, predictable fire resistance solution using factory-tested board systems assembled on site.

This is not cladding. It is structural fire protection.

What Is Fire Protective Boarding and Encasement

Fire protective boarding involves mechanically fixing fire-resisting boards around structural steel members to form a complete protective enclosure.

When exposed to fire, the board system insulates the steel, slowing heat transfer and maintaining loadbearing capacity for a defined resistance period.

Encasement systems are designed as complete assemblies, including:

• Fire-resistant boards

• Fixings and support framing

• Joint treatments

• Edge and interface detailing

Performance depends on the system being installed exactly as tested.

When Boarding Is the Correct Fire Protection Solution

Boarding and encasement are typically specified where:

• Steel is located in occupied or finished areas

• A decorative or smooth finish is required

• Environmental conditions prevent spray application

• Impact resistance is necessary

• Services require integrated protection

It is a controlled, architectural solution where steel remains visible or accessible.

Fire Resistance Periods Achieved

Fire protective boarding systems are specified to achieve standard resistance periods, including:

• 30 minutes

• 60 minutes

• 90 minutes

• 120 minutes

The required thickness, number of layers, and fixing pattern are dictated by:

• Steel section size

• Exposure conditions

• Tested system data

No deviation is permitted.

Tested Systems and Regulatory Compliance

All encasement works are carried out using manufacturer-tested systems assessed under relevant standards, including:

• BS 476

• Applicable EN fire test standards

Each system defines:

• Board type and thickness

• Fixing centres and edge distances

• Joint treatment and sealant specification

• Orientation and fire exposure direction

Substitution invalidates compliance.

Installation Process — Precision by Design

Boarding is unforgiving of shortcuts.
The installation sequence typically includes:

1. Verification of steel dimensions and condition
2. Installation of support framing where required<
3. Accurate cutting and fitting of boards
4. Controlled fixing in line with test evidence
5. Joint sealing and detailing<
6. Final inspection and recording

Tolerance is engineered, not guessed.

Detailing at Interfaces and Junctions

Most failures occur at edges.

Particular attention is given to:

• Floor and soffit junctions

• Service penetrations through encasement

• Interfaces with fire stopping systems

• Continuity with walls and ceilings

Encasement must remain continuous to the fire compartment line.

Quality Assurance and Documentation

Fire protective boarding is evidence-led work.

QA records typically include:

• System specifications and drawings

• Product data sheets

• Installation photographs

• Fixing and joint verification

• Installer competence records

This supports Building Safety Act requirements and contributes to the Golden Thread of information.

Common Failures Seen with Boarded Systems

Failures are usually procedural, not material.

Typical issues include:

• Incorrect fixing centres

• Incomplete joint sealing

• Board substitutions

• Poor interface detailing

• Missing documentation

Each compromises the fire resistance period.

Integration with Passive Fire Protection Strategy

Encasement does not stand alone.

It must integrate with:

• Fire stopping at service penetrations

• Intumescent protection elsewhere in the structure

• Fire-resisting walls and floors

• Cavity barriers and compartment lines

Coordination preserves system integrity.

Sectors and Applications

Fire protective boarding and encasement is used across:

• Commercial and office buildings

• Residential and high-rise developments

• Education and healthcare facilities

• Refurbishment and live environments

• Plant rooms and service areas

Where control, durability, and finish matter, boarding is decisive.

Why Choose JW Simpkin Ltd?

• Over 75 years of fire protection experience

• Fully trained and certified applicators

• On-site and off-site capabilities

• Nationwide UK coverage

• Integrated passive fire protection services

Our intumescent painting service integrates seamlessly with our wider passive fire protection offering, including fire stopping, fire boarding, cavity barriers and fire doors.

Intumescent Painting Contractors UK

If you require compliant Fire Protective Boarding & Encasement, JW Simpkin Ltd provides a reliable, certified solution from specification through to completion.

For more information on Intumescent Paint for a quote call us today on 01332 664700 or make an enquiry using the form below