What Is Intumescent Coating?

Intumescent coatings are specialist passive fire protection products applied directly to structural steelwork. In the event of a fire, the coating reacts to heat by expanding rapidly - forming a thick, insulating char layer that dramatically slows heat transfer to the steel beneath. This buys critical time for building evacuation and fire response, and protects structural integrity for a defined fire resistance period.

Unlike traditional fire protection methods such as board encasement or spray fireproofing, intumescent coatings are applied as a thin-film system that can be finished to a high aesthetic standard - making them the preferred choice for architecturally exposed steelwork in commercial, industrial, and institutional buildings.

Compliance & the New Zealand Building Code

Under the New Zealand Building Code (Clause C Protection from Fire), structural elements in most commercial and multi-storey buildings must achieve a specified fire resistance rating. For structural steel, this is typically demonstrated by applying a tested and approved intumescent coating system to the appropriate dry film thickness (DFT) for the required fire resistance period.

Getting this right is not optional - and it is not straightforward. The required DFT depends on the section factor of each steel member, the fire resistance period specified, the product system being used, and the substrate condition. Incorrect application can mean non-compliance, failed inspections, and potentially catastrophic risk.

JPB works with specifiers and contractors to ensure intumescent coating application meets the requirements of the specified system, and can assist with documentation to support building consent and code compliance processes.

JPB's Intumescent Coating Capability

Our painters are trained in the application of thin-film intumescent systems for structural steel, and we work closely with our paint supplier partners - Carboline, Dulux, Zone and FireSheild - to ensure we are using approved systems that are correctly specified for the project. Our work includes:

• Surface preparation of structural steelwork to the standard required by the intumescent system manufacturer

• Application of primer, intumescent basecoat, and topcoat in accordance with the product data sheet and project specification

• Dry film thickness and environmental measurement and documentation throughout the application process

• Coordination with fire & structural engineers and building consent authorities where required

• Application on both new construction projects and remediation or upgrade projects

• Work across a wide range of structural steel configurations including beams, columns, trusses, and connections

Where We Work

Intumescent coating is commonly specified on:

• Commercial office and retail buildings with exposed structural steel

• Industrial and warehouse buildings requiring passive fire protection to steelwork

• Multi-storey car parks and mixed-use developments

• Institutional buildings including schools, hospitals, and civic facilities

• Infrastructure and transport structures with fire resistance requirements

• Mezzanine floors and structural steel elements in existing buildings undergoing refurbishment or change of use

Our Process

We approach every intumescent project with the same rigour we bring to all compliance-critical work.  We manage each project from pre-application review to code of compliance sign off.

Discuss Your Project With Us

If you are a project manager, engineer, or contractor with a structural steel project requiring fire protection compliance, we welcome the opportunity to discuss how JPB can support your programme. We work from design through to compliance documentation, and we bring the precision and accountability that passive fire protection work demands.

Phone: 027 3626592     |   Email: office@jpb.co.nz