Screen spline and flat screen spline

Spline is a available in quite a variety of shapes and sizes. The average hardware store stocks only a couple of sizes. Most likely the frame you have to work on requires the size they dont have.

Your local glass shop may well sell you the right size you need, just rememeber to bring a sample of the old that you removed so you can be sure to get the size right. If you still cant find the right size, check the link at the end of this page.

Spline comes in rolls that look like electrical wire, except it is solid all the way through. Often you will see "Polyfoam" which is like foam rubber except with very small air bubbles. It is available in sizes measured in decimals of an inch. For Example #140 is .140 of an inch.

The most common sizes or diameters in Southwestern Ontario, Canada, where I live are .160, .180, .200 and .250 inches diameter. I believe the above sizes are pretty common across North America too.The sizes used depend on who the predominant supplier of windows was when most of the houses were built in your area.

The .250 size replaces the 1/4" aluminum spline that was used in houses built in th e fifties and sixties. This size is particularily easy for the do it yourselfer to roll in.

Spline is made in many different materials . There is EPDM which is a kind of hard rubber, there is also hollow core vinyl. Hollow core vinyl can be stretched as you roll it in, which helps if the diameter is just a little too big for the frame you are working on. Polyfoam is best for the beginner though because it can be used in wider variety of frame styles and is easier to roll in.

There is also "T-spline" that is used a lot in the very thin screen frames used in aluminum storm doors. This is usually made of extruded vinyl and its cross section has the shape of a letter "T". It also is available in the same size descriptions as polyfoam. When you roll this in you have to get the flat top of the letter T to lay down in the spline channel. That way it locks the screen material in place much more surely than regular polyfoam spline. With the T stuff however, you have to have exactly the right size, otherwise it just will not work.

Some window manufacturers have used weird and wonderful shapes in their custom screen doors in the past. Some of them have used glazing vinyl to hold the screen cloth in. Your local glass shop can probably help you sort out these situations and get you the right material.

Screen Spline size and usage chart

Spline size (inches)	Fraction	Notes
.120 round	1/8"	used in some patio screen frames
.160 round	11/64"	Very popular round black screen spline 500 Roll' - used in many screen door frames
.160 T spline	11/64"	Used in window and screen door frames, "T" shaped spline locks screen cloth down tighter than round spline.
.180 round	3/16"	Very popular - Used in both window and screen door frames
.180 T spline	3/16"	Very popular in storm door screen frames because of its low profile.
.200 round	13/64"	Used in window and screen door frames
.250 round	1/4"	Direct replacement for old aluminum box spline and round steel spline used in the 1950's and 1960's
.250 T spline	1/4"	Used mostly in storm door window frames due to its low profile and because of its ability to hold the screen in tighter than round spline.