Some screens lift straight out. Some have springs, tabs or plungers. Others have twist locks or clips. Some need the window itself removed first. Occasionally you'll come across a screen that seems to have been made just 1 mm too large for its opening. I've been cleaning windows professionally for 25 years, and I've come across a lot of different designs.

There are probably over a dozen different fly screen designs out there. But they all fall into three broad types, and knowing which one you're dealing with changes everything. Type 1: Sits inside a groove in the aluminium window frame These screens live in a channel that runs around the inside or outside of the frame. When the channel is on the inside, to get them out, you often need to remove the sliding window first, then the screen slides or lifts free from the