What is the function of a blind strap in window installation?

A blind strap serves an important role in window installation by acting as a stop for the top sash. It helps to limit the movement of the window's upper panel, ensuring that it does not slide beyond a designated point, which is crucial for maintaining the structural integrity and functionality of the window. This function is particularly important in double-hung windows, where both the top and bottom sashes can move. By preventing excessive movement, the blind strap contributes to the overall performance of the window, promoting ease of use and ensuring a proper seal when the window is closed. This helps maintain energy efficiency and contributes to the longevity of the window system.

While other functions like providing insulation, holding the frame together, or preventing water leakage are important aspects of window performance, they are not the primary role of a blind strap.