A practical flyscreen repair and replacement decision starts with the affected item, its condition and the surrounding materials. Fit suitable mesh and spline to an accepted sound frame, or install a compatible ordinary supplied screen and check its fit.
Signs: the window does not close, catch or sit evenly as it did before or the window is stiff, loose or no longer moves through its normal range. Causes: movement, dirt or damage around the relevant hardware or normal wear in accessible moving hardware.
Measure the existing screen and show how it sits in the opening. Overall dimensions alone may omit clips, recesses or clearance. A customer-supplied replacement should be checked against the fixing arrangement before purchase, especially where the old screen is missing.
Mesh needs suitable tension without distorting the frame. Corners and long sides should be checked during fitting, following the material requirements. Over-tightening is not a way to strengthen an old frame, and loose mesh may reflect a retaining-channel problem.
Handle the screen by its frame and follow mesh care instructions. An insect screen is not a security barrier or fall-prevention device. Limits: Ordinary insect mesh and compatible screen frames only. No security screens, fall-protection claims, specialist glazing or inaccessible high-level work.