Intumescent Paint for Structural Steel and Cast Iron

ISS Paint is an intumescent coating for structural steel and cast iron.

During a fire chemicals in the paint expand up to 50 times the paint film thickness to form an insulating char layer. The char keeps the steel below critical temperature to maintain the structural stability of the building.

One coat can provide fire resistance of ½ hour and 1hour. Two coats can provide 1½ hour fire resistance. ISS Paint is available in 5 kilo and 20 kilo containers

Steel and cast iron should be free from rust and millscale and primed with our HBP high build primer 75 microns DFT or other primer compatible with intumescent paints. Galvanized steel or Stainless Steel should be degreased and then primed with a suitable primer.

A decorative flame retardant topcoat  can be applied see Flame Retardant Paint

Technical advice and support is important in the selection and application of intumescent paints and we are happy to provided specifications and quotations - please use our structural steel enquiry form .

For certification and compliance with regulations we will supply a Certificate of Supply with each order or for each project.

The paint can be applied by brush or roller.

We recommend the use of airless spray equipment for large areas

Graco 5000 or 7500
Filter size 30 mesh
10mm hose with no whip end
Tip size : 317-319 (6" fan) - Narrow surfaces 417-419 (8" fan) - Broad surfaces
Cleaner: solvent or water depending on paint type.


Max. Relative Humidity 80%.
Min. Temperature 6°C.
Min. Surface Temperature 3°C above dew point
Max Thickness per coat; brush 600 microns
Max Thickness per coat; spray 2000 microns (S)
Max Thickness per coat; spray 1400 microns (W)

The above information to the best of our knowledge is true and accurate and based upon current test data and is supplied for your guidance only. Customers should satisfy themselves to the suitability of the product in its intended use and no guarantee is given or implied since the conditions of actual use are beyond our control. We disclaim any liability for loss, damage or other expense arising from the use of information, data or products mentioned or referred to and reserve the right to change any details or specifications without notice.