Repairing or replacing the mesh in window screens is a quick way to stop insects such as mosquitoes from invading your home and to keep your house looking well cared for. To start, it's a good idea to clean the screens annually. For a quick clean, brush them to remove dirt and dust. For a more thorough cleaning, remove them from the window, spray them gently with a garden hose, and then brush or sponge them down with a solution of hot water and all-purpose detergent.
Small gaps in the screen can result from the mesh weave becoming uneven or stretched. That's easily fixed with a toothpick or straightened paper clip; just move the individual strands of mesh back into place.
Mesh screen comes in a variety of materials and colors. Buy replacement mesh screen that matches your existing screen, to avoid having one window that looks significantly different from the rest
There are several ways to patch holes in mesh screens, but they all result in a fairly visible repair. They are, however, good temporary fixes until you have time to replace the entire screen.
Very small holes in mesh screen can be sealed with several coats of clear nail polish or clear-drying glue (allow each coat to dry between applications, and poke a toothpick through the individual mesh holes before each coat dries). For rips, realign the individual mesh wires as closely as possible with a toothpick or awl; then run a piece of wire or low-visibility cord (such as fishing line) back and forth across the rip, as if you're sewing or weaving it back up, to close it.
You can buy mesh patches that are designed to cover holes, or you can create a patch from a piece of spare screen. The patch should be slightly larger than the hole. First, trim any loose wires from the edge of the hole, and flatten any protruding wires to create an even surface for the patch. Glue the patch to the screen around the hole using clear-drying glue or caulking, or sew the patch into place with wire or low-visibility cord (use a curved upholstery-type needle so that you can make the repair from just one side of the screen).
Replacing Aluminum-Frame Screen Mesh
You'll need a splining tool for this repair; it has a handle with a roller on either end. Several spring-loaded clamps are also useful for keeping the mesh straight in the frame.
Remove the window screen, in its frame, from the window or door. A narrow channel runs around the frame, holding a length of spline (cord) that secures the screen. Pop out the old spline with an awl or flat-bladed screwdriver.
Cut the new mesh to fit the frame, plus 2 inches extra on all sides. Lay the new mesh over the frame, ensuring that it's straight, and clamp it into place on each corner of the frame (or have someone hold the mesh).
Now insert the new mesh and spline into the spline channel. For aluminum mesh, you'll first need to use the convex (outward curving) roller on the splining tool to gently crease the mesh into the spline channel, taking care not to cut or tear it. If you're using clamps, you may need to release them on the opposite side in order to do this, but be sure to reattach them as you make your way around the window.
Clamps keep screen mesh from shifting as you roll it into the spline channel.
For all types of mesh, use the concave (inward curving) roller on the splining tool to roll the spline into the channel, taking the screen with it. Remove the clamps as needed, pulling the screen snug on the opposite side to eliminate wrinkles or bunching, but not so snug that you pull the window frame out of alignment. Cutting away excess mesh at each corner at a 45-degree angle will help avoid bunching.
The splining tool will have a tough time fully seating the spline at the corners of the frame; use a flat-bladed screwdriver to push the spline into place there. Carefully trim the excess screen with a utility knife, angling the knife away from the newly installed mesh to avoid accidentally cutting it.
Replacing Wood-Frame Screen Mesh
Remove the wooden frame from the window, and use a flat-bladed screwdriver or small pry bar to pop off the molding that's covering the edges of the screen. Run a utility knife blade through the paint around the molding, if necessary, to free the molding from the frame.
Cut new mesh to fit the frame, plus 2 inches excess on all sides. Lay the mesh over the frame so that it's straight, and clamp it to the frame or have someone hold it in place, pulling it snug. Staple the mesh to the window frame on all sides, making sure that it doesn't wrinkle or bunch.
Reapply the molding with small nails, and then carefully trim the excess screen by running a utility knife around the window frame, with the blade cutting between the molding and the frame so that you're not cutting against a wood surface that can be seen.