Thermoguard Thermocoat WO is a high-performance, water-based intumescent paint system designed to provide up to 90 minutes of fire protection for structural steel and cast iron. Specially developed for use on hollow sections including CHS, SHS and RHS, this coating delivers efficient fire resistance with minimal coats required - helping to save time and reduce labour costs on large-scale projects.

Its low odour and water-based formulation makes it safe for use in occupied buildings and more environmentally friendly than solvent-based alternatives. When combined with a compatible Flame Retardant Topcoat, the system enhances the look of exposed steelwork while meeting UK fire certification standards.

For open sections such as Universal Beams and Columns, use Thermocoat WI. For external steel, see Thermocoat S.

✅ Ideal for commercial, industrial and public-sector fire protection projects
✅ Compatible with decorative topcoats in BS 4800 and RAL colours
✅ Suitable for internal and sheltered external environments

How It Works:

When exposed to fire, Thermocoat WO expands up to 50 times its original thickness, forming a dense insulating char. This slows the temperature rise of the steel beneath, allowing the structure to maintain load-bearing capacity for up to 90 minutes.

📄 Fire Testing & Certification:

• Independently tested and assessed by UKAS/EGOLF accredited labs

• Conforms to BS 476 Part 21 – Fire resistance for load-bearing elements

• A Certificate of Supply can be issued upon request for building control and insurance compliance

Surface Preparation

• All steel and cast iron must be clean, dry and free from rust, oil and millscale

• Prime with Thermoguard Steel Fire Paint Primer to 75 microns DFT (or an approved anti-corrosive primer suitable for intumescent coatings)

• Galvanised surfaces must first be treated with Teamac Mordant Solution (T Wash) before priming

• Always follow manufacturer’s instructions and allow primers to fully dry before applying basecoat

Technical Data