Thermocoat WI water-based intumescent paint system provides up to 120 minutes fire resistance to structural steel and cast iron. Architectural and design features can be enhanced with use of a compatible decorative overcoat system. (Range of topcoats are either water-based or 2010 compliant and safe to use in accordance with manufacturer’s instructions).
Thermocoat WI is optimised for I and C shaped steel and hollow bracing. For hollow posts, see Thermocoat WO.
How do intumescent coatings work? Heat from a fire triggers a catalytic reaction and causes the insulating char layer in the coating to expand to up to 50 times the paint thickness. This layer keeps the steel below its critical temperature for longer (time specified with the coating) maintaining the structural integrity of the steel.
Thermoguard Thermocoat WI is low-odour and water-based making it user and environmentally friendly. It’s also easy to apply by brush, roller or airless spray.
- Water based Intumescent for structural steel
- For 30 mins protection: 1 thick coat – 2.5kg 4 linear m, 5kg 8 linear m, 20kg 32 linear m – if in any doubt please contact us.
- For 60, 90 or 120 minutes protection: contact us for further advice specific to your project
Please Note: If certification is required, an intumescent enquiry form must be completed prior to purchase of the product, as this will ensure the correct quantity is applied to achieve the fire rating. The enquiry form is available to download from the ‘Data Sheets’ tab.
Important Notes for Application
Ensure steel is free from rust and millscale and primed with Thermoguard High Build Metal Primer to 75 microns DFT ( or alternative good quality anti-corrosive primer compatible with intumescent paints) in accordance with manufacturers instructions. Treat galvanised surfaces with “T” wash/Mordant solution & prime with zinc phosphate or other primer for steel.
Apply Thermocoat WI by brush, roller or airless spray as per recommended specification – important please contact us to obtain a basecoat application schedule ( a wet film gauge will be supplied with the product to help comply with the spec).
* Ensure basecoat is fully dry (hard to the touch) before applying decorative topcoat. Note that temperature and humidity will affect drying times.
Basic Drying and Overcoat Times Under Normal Conditions
Brush / Roller Application
- Surface dry: minimum 2 hours
- Recoat: minimum 4 hours
- Overcoating with Flame Retardant finish: minimum 10 hours
- Surface Dry: minimum 4 hours
- Recoat: minimum 10 hours
- Overcoating with Flame Retardant finish: minimum 48 hours