FireproofingMaterials · Planning guide
Planning an intumescent finish for exposed structural steel
Architectural appearance belongs in the brief alongside the fire-protection design.
This guide helps you prepare a professional conversation. It does not specify a rated system, product thickness or installation method.
An appearance decision with a technical design behind it
Intumescent fire-resistive coatings can be considered where structural steel remains visible. Carboline describes Thermo-Sorb 263 as a thin-film intumescent coating for interior steelwork and publishes separate product data, submittal and certification documents. The product page is an introduction to a specific product, not evidence that it suits every exposed column.
Describe what you want to see
Give the architect photographs or drawings of the intended visual result, including the visibility of connections, the desired colour and the surfaces that will remain exposed. Ask how samples or mock-ups will be reviewed and who approves the finish. Discuss likely handling, later trades and access for inspection. Separating the appearance review from the technical design review helps prevent a decorative sample from being mistaken for an approved fire-protection solution.
Keep the complete proposed system together
Request that the design team identify the proposed coating system and the supporting project-specific documents. Record which primer and finish choices have been reviewed, and ask how later changes will be controlled. Do not assume that ordinary repainting is interchangeable with an approved finish. The owner’s role is to make the appearance and maintenance expectations clear, while the responsible professionals determine suitability. A manufacturer’s maximum advertised rating is not the rating of your steelwork.
Review one representative area
Before approving the visual direction, choose a representative beam or column with the architect and ask what a mock-up would demonstrate. Agree whether the review concerns texture, colour, connections or another visible feature, and write down what it cannot establish. Keep photographs and comments with the finish schedule. If a later tenant asks for a new colour, that record gives the manager a starting point for obtaining advice rather than authorizing an ordinary decorating job from memory. The appearance decision and the technical acceptance can be tracked together while remaining separate decisions made by the appropriate people.
Primary sources & further reading
Published November 11, 2026 · Fireproofing.tv editorial desk