Composite materials are increasingly been used in a variety of fields such as transportation, civil engineering, etc. However, despite their unique characteristics, composite materials have been known to be highly susceptible to fire. To effectively access such risks, the current research studies the intumescent surface coating thickness effect on carbon, glass fiber reinforced epoxy and sandwich composites. These specimens were subjected to 30 kW/m2 flame for 150, and 300 s using butane burner as the fire source. The results showed that tensile, flexure, impact and compression properties decreased rapidly as the heat-exposure time increased. There was a significant improvement in the post-fire mechanical properties in thermally-protected carbon and glass/epoxy laminates and sandwich structures compared to specimens without intumescent protection. This result is due to the intumescent protection and ability of the charred layer to effectively reduce the transferring of heat to the substrate.