A method of determining the unmodified temperature, T1, for elimination of thermal strain from the load testing is presented. It is based on the fact that the intersection point of two T–ε lines for a test point shows zero stress (or strain) and coincides with the known zero stress at the neutral axis of the structure, if the test point is set at the axis. The abscissa of this intersection point indicates the unmodified temperature T1. The method has been applied to the load test on a suspect beam in a 4‐storey building. The conclusion was reached that although the suspect beam was weaker than normal, it could take the assigned load without any remedial measures. This conclusion was verified by the practical evidence of normal service for more than five years.The method is applicable to certain types of structures at the mo