Passive Fire Design – Intumescent paint systems

In October 2020, a “Code of Practice for the Specification and Application of Intumescent Coatings for the Fire Protection of Structural Steel” was published by the Fire Protection Association of New Zealand.

It includes a requirement to keep all structure clear of the steel by a distance of 50x the dry film thickness of the coating. It is no longer acceptable to fix timber directly to coated structural steel to accommodate the protective foaming of the intumescent paint during a fire or for the fixing of linings. It will also be a requirement to have access to the steel to inspect the state of the coating when ‘life to first maintenance’ inspection is required.