How to make a DIY fly screen for your windows
Step 1 - Measure the opening of the window
To measure the opening of the window, you can either take measurements from undamaged sides of an original screen, or measure the width and height directly from the window. Allow 3mm clearance for fitting and make sure that window is square by checking that diagonals are equal.
If screen is held in tracks, measure from inside of top track to outer top edge of bottom track so screen can be pushed into top track, then settle into shallower bottom track. Buy enough track for window or windows that need screening.
Step 2 - Secure the mitre box
Screw fly screen mitre box to a bench or saw stool to hold it steady.
Step 3 - Cut aluminium frame to size
Put frame, channel-side up, in mitre box. Use hacksaw to cut a 45° angle at 1 end of frame so channel will be on inside of mitre.
Step 4 - Measure the outside of the frame
Measure length of frame piece from long point to long point (this will be the outside of a frame side) and cut a 45° angle in opposite direction. File cut metal to remove metal burrs. Cut other 3 sides of frame.
Step 5 - Join corners together
Insert corners and push frame tightly together. Check fit of frame in opening.
Step 6 - Secure fly screen mesh
Put frame, with spline channels facing up, on a flat surface. Roll out mesh over top and align weave with frame. If it’s too large, cut so there is about 50mm overhanging all around. Use spline and spline roller to force mesh into grooves to hold mesh tight. This action will also tension mesh. If it goes wrong or wrinkles, simply pull out spline and do process again. If spline is too hard to press in, try placing it in hot water first to make it more pliable.
Step 7 - Cut away excess mesh
Use utility knife to trim excess mesh on outside of spline. Add catches and clips to screen or window as necessary and fit screen in place. Repeat process for other screens.