This work is focused on the development of single and hybrid fibers reinforced intumescent fire-resistant coating for steel protection. The methodologies were developed to measure the heat transfer, thermal stability, char expansion rate, chemical bonding and composition of char, residual mass percentage as well as morphology of an intumescent coating. By incorporating 2 wt. of single basalt fibers in the intumescent coating, the substrate temperature remained stable at 184 oC after 60 minutes of fire test. On the other hand, the hybridization of E glass with the basalt fiber IFRC-BE55-12 in intumescent coating resulted in higher substrate temperature. Field emission scanning electron microscopy (FESEM) confirmed IFRC-B2.5�12 formulation had a compact and dense char. The thermogravimetric analyses results also revealed that thermal stability of the fibers reinforced intumescent formulations was improved and the highest residual mass of 38.7 percentage was obtained for IFRC-B2.5�12. © 2022 Informa UK Limited, trading as Taylor & Francis Group.