How to Use a Screen Installation Tool

screen installatoin tool
A screen installation tool has a concave and a convex roller, one on each end. home-cost.com

If you are installing a new screen or making a screen repair to a metal-frame screen or a screen door, you will need a special tool used to install the vinyl cord, or spline, that secures the screen inside the channel of the screen frame. This tool is called, simply enough, a screen installation tool. It's also called a screen rolling tool or a spline roller.  

Why You Need a Spline Roller 

A spline roller may be a uni-tasker (a tool that has only one job), but it's one of those tools that makes an easy job easy.

And if you don't have one, that easy job is sure to turn into a comedy of errors (and swearing). 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, flat edge (this is the convex wheel) and the other has a grooved edge (this is the concave wheel).

The concave wheel is used only with metal screen, to push the new screen into the channel of the screen frame before you install the spline. You have to pre-shape the screen into the channel so that the spline will go in willingly. The convex wheel is used to press the spline -- with screen beneath it -- into the channel. With fiberglass screen, you can do this in one motion; no pre-shaping is necessary. 

Regardless of the screen material, no other tool in the house can do what a spline roller does. A pizza cutter might seem like a good substitute, but it's too sharp, and the wheel is too big for proper control and leverage.

So don't try a pizza cutter. Or a screwdriver, which will not tighten the screen evenly and will surely leave you with many frustrating holes in the screen and a badly marred spline. 

How To Install Screen Spline

After cutting the new screen to size (a few inches larger than the frame) and, if it's metal, using the convex wheel of the spline roller to press the screen into the frame channels, it's time to install the spline:

  1. Starting at one corner, press the end of the spline into the corner of the screen frame, using the concave (grooved) wheel of the spline roller. You can use the entire bundle of spline and cut it off when you're done. 
  2. 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. Also, move the roller with short strokes, going in one direction. Try not to go back and forth.
  3. Press the spline into corners, as needed, with a small screwdriver. Be careful not to cut through the screen with the screwdriver. 
  4. Work your way around the frame in one direction. Again, the spline will tighten up the screen. 
  5. When you reach the starting corner, cut the spline with scissors or a utility knife and press the end into the channel. Trim the screen flush to the outside of the spline with a utility knife to complete the job. 

Tip: 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 size of spline as the original.

If the new screen is thicker than the old, choose one size smaller for the spline.