In the intumescent fire retardant (IFR) coating char thickness and its strength play a vital role to protect the base steel structure from the fire. The IFR coating contains expandable graphite (EG), ammonium polyphosphate (APP), melamine, boric acid, bisphenol, epoxy resin BE-188 (BPA) which is used as a binder with ACR hardener H-2310 polyamide amine and multi wall carbon nano tubes (MWCNTs). A range of different formations were prepared to study the heat shielding effect and char expansion after fire test. The intumescent coating was tested at 800°C for one hour in the furnace and found to be very stable and well bonded with the steel substrate. The characterization was done by using Thermo gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and Field emission scanning electron microscopy (FESEM) after fire test. The results confirmed that MWCNTs enhanced the char resistant of IFR coating on steel substrate after fire test. © (2012) Trans Tech Publications.