How to Use a Spline Roller

Installing a new screen on a door or window requires a special tool called a spline roller. When making repairs to screens, this tool is used to install the vinyl cord, or spline, that secures the screen inside the channel of the screen frame. Spline rollers are sometimes called screen installation tools or screen rolling tools, and these handy tools are used to repair metal-frame screens, screen doors, and window screens. Keep in mind that spline rollers cannot be used to repair wooden frame screens. While this tool may only serve one purpose, it's an essential component for completing screen installations—and it makes the job much easier.

Parts of a Spline Roller

A standard spline roller consists of a wooden handle with a metal wheel on each end. The wheels appear identical at a glance, but close inspection reveals that one has a thin edge grooved outward (this is the convex wheel) and the other has an inward-grooved edge (this is the concave wheel).

The convex wheel is only used when installing metal screens. This pushes the new screen into the channel of the screen frame before you install the spline, pre-shaping the screen inside the channel so the spline will go inside willingly. The concave wheel is used to press the spline—with the screen beneath it—into the channel. With a fiberglass screen, you can do this in one motion; no pre-shaping is necessary.

What Spline to Use

Spline comes in several different diameters, from 9/64 (0.14) inch to 7/32 (0.21) inch. If the replacement screen is the same type as the old material, use the same spline size as the original. If the new screen is thicker than the old screen, choose one size smaller for the spline. It's helpful to bring a piece of your old spline to the hardware store with you to compare different sizes until you find the right option.

How to Use a Spline Roller

If you're repairing the screen on a sliding door, you'll need to remove the screen door before replacing the screen and spline. Always cut the new screen to size first, leaving it a few inches larger than the frame.

If you're using a metal screen, it's important to pre-fit the screen into the frame channels before adding spline (this step is not necessary for a fiberglass screen). Lay your metal screen over the door or window frame and use the convex wheel of your spline roller to press the metal screen inside. Once your screen is prepared, it's time to install the spline as you would with fiberglass screen in the steps below.

1. Start With One Corner

   Lay your fiberglass screen over the door or window frame, then begin installing spline on top to secure it inside. Starting at one corner, press the end of the spline into its channel, using the concave (inward-grooved) wheel of the spline roller.

   Tip

   Don't cut the spline to fit each side—you can use the entire bundle of spline in one piece around the frame, then trim any extra when you're done.

2. Roll the Spline

   Move the roller along the spline, forcing the screen and spline into the frame channel. As you go, you can tug gently on the edge of the loose screen (ahead of the roller), so it stays flat, but do not pull it tight; the action of pushing the screen into the channel will tighten it as you move around the frame. Move the roller with short strokes, going in one direction. Try not to go back and forth.

3. Use a Screwdriver for Corners

   Bend the spline around each corner as you reach them and press the spline into corners, as needed, with a small screwdriver. Be careful not to cut through the screen with the screwdriver. Only touch the screwdriver to the spline itself to avoid making holes in your new screen.

4. Finish Each Side

   Work your way around the frame in one direction to finish each additional side of your screen. Continue gently holding the loose screen tight, but remember that the spline will tighten it to a degree on its own.

5. Trim Additional Materials

   When you reach the starting corner, cut the excess spline with scissors or a utility knife and press the end into the channel. Trim the extra screen to make it flush with the outside of the spline.

Keeping Spline Rollers Clean

Since spline rollers are rarely used in most households, their wheels can develop buildup from being stored in toolboxes or drawers that collect dust. If your spline roller's wheels begin to stick, simply rinse it off and wipe it down with water or a degreaser like WD-40. When using water, dry metal wheels afterward to prevent rust.

When to Replace Your Spline Roller

Some spline rollers have plastic wheels that can become cracked or damaged over time. Once one of the wheels is cracked, the tool will not function properly. Thankfully, spline rollers are typically affordable, and a new tool can be purchased at most hardware stores.