Standard Windows Sun Screen Mesh Size

Some large glass patio doors have screens installed.

Window screens consist of mesh made with aluminum wire, fiberglass or synthetic fibers such as plastic or polyester. The size of the mesh refers to the number of spaces that exist within a square inch of the woven material. Different types of window screens are used for a variety purposes; for instance, smaller screens are used to keep out tiny insects such as gnats. Solar insect screens not only keep out bugs, but reflect solar heat and sun light to block up to 90 percent of sunlight and heat from entering your home during summer months.

Template

Cut a 1-inch-by-1-inch square from the center of a piece of paper to make a counting template. The mesh size is determined by counting the number of openings it has per square inch. The paper cut out will help you keep track of the line of openings as you count them. Align the edges of the cut out square with the warp or wires that form horizontal and vertical lines in the mesh. Hold the paper in place on the window screen with tape.

Count

Count the number of tiny square openings made by the mesh wires in a straight line across from the top left corner over to the top right corner. This is the first number of the mesh size called the warp or foundation of the mesh. Next, count the number of tiny square openings in a straight line from the top left corner down to the bottom left corner. This is the second number of the mesh size, called the fill or width of the mesh. These two dimensions are the size of the mesh. For instance, 18 warp openings and 16 fill openings means that the window screen mesh size is 18-by-16, which is written as "18x16" on the screen packaging.

Measure

The diameter of mesh size refers to the diameter or width of the wire or threads of the mesh. Use digital calipers to measure the diameter of the wires or threads of the window screen. Set the caliper jaws over the screen mesh and close them to take a reading and find the diameter of the mesh. If you do not have access to digital calipers, there are wire cloth or mesh calculators available online that you can use to find the wire mesh diameter.

Screen Selection

Some window screen meshes are coated or laminated with a layer of plastic, making them more durable to encounters with pet paws or inquisitive children's hands pressing on them. The standard window screen mesh is 18-by-16 and made out of fiberglass or aluminum. Patio, porch or pool side screens have a mesh size of 18-by-14. The smallest sized mesh is 20-by-20; the tightly woven mesh allows for ventilation while still keeping out tiny insects.