Operational Strain Modal Analysis (OSMA) holds significant potential for Structural Health Monitoring (SHM), requiring only strain respondes from the structure under investigation. Due to ther high sensitivity, Strain Mode Shapes (SMS) can serve as a robust alternative for detecting and locating structural damage. This study presents a cost-effective damage detection method using seven strain gauges installed on a glass beam. Strain responses were processed to derive SMS, which were then compared to mode shapes obtained through traditional Operational Modal Analysis (OMA), showing strong agreement. The work experimentally demonstrates the accurate detection and localization of small damages in a glass beam by combining OSMA with Continuous Wavelet Transform (CWT). This approach highlights the capability of OSMA to detect subtle damage patterns efficiently. Furthermore, the low-cost nature of the presented method makes it a promising alternative for various SHM applications, such as monitoring wind turbine blades or other critical structures. By leveraging OSMA, this work aims to contribute to the development of affordable and practical SHM techniques for field applications.