Replacing a torn or broken screen is easy if it is held in place with a flat spline. A spline is a flexible strip used to ease two different materials together. Flat splines are used in window and door screens to secure the screens inside the frame without adhesives. You can find the materials to replace a screen with a flat spline in any hardware store and do the repair yourself in very little time.
Lay the window frame on a table.
Pry the flat spline out of the groove around the inside of the window frame. Use a screwdriver as a wedge to completely remove the spline from the frame.
Remove the old screen and dispose of it.
Wipe down the frame with a cloth. Remove any dirt that has gotten lodged inside the groove where the screen and spline sat.
Lay the new screen over the empty frame and cut it with scissors. The screen should extend over the frame by 1/8 of an inch on each side.
Square each corner of the screen so it no longer comes to a point. Cut the screen at a 45-degree angle to square it.
Push the screen into the groove in the frame using a screen rolling tool. Use the rounded end of the tool to get the screen in place.
Line the flat spline along the groove in the frame, on top of the screen.
Insert the spline in the groove using the concave or depressed end of the tool. Slowly press the spline into the groove.
Place screen back in window.