At present, there is no harmonized test standard to determine the contribution of tensioned solid steel braces protected by intumescent paints on fire resistance. For this reason, the adaptation of the Bridge Pavilion built in Zaragoza for the International Exposition (2008) and its adaptation to a new use made it necessary to design a test protocol that allowed determining the time equivalent to Standard Fire Resistance for those metallic structural elements. This paper presents both the methodological design and the results obtained in this specific case. The experimental scheme allowed us to verify that a thickness of 4 mm of intumescent paint guarantees a fire resistance R60, and a thickness of 5 mm guarantees the resistance R90, both cases for loaded braces. The applied protocol allowed us to check the difficulties to apply the paint on elements of reduced dimensions, concluding that the most appropriate solution was application by brush and subsequent sanding to avoid irregularities and excess paint. This information was essential when planning the subsequent application to the real case.