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Asking the question: What do lines on a railing system mean?

Two-Line? Three-Line? How about some guide-lines!

  •   Posted on September 24, 2019

The number of “lines” in a given railing system is critical to the overall project design, but the terminology often leads to confusion. So, what does two, three, four, etc. line railing ACTUALLY mean?

All design aspects of an aluminum railing system are critical to the overall look of the project, be it railing type, finish, size, or otherwise. The question at hand, the meaning of those numbers in front of “line” in a railing system, is simply put another characteristic of the overall design of a railing project.


The short answer to the question is actually fairly simple. The number of lines listed refers to the number of horizontal runs of top/bottom railing included. Cables in cable railing are generally not counted as lines in this traditional sense, nor are horizontal pickets in a system designed with them.

A comparison of two-line and three-line aluminum railingTwo-Line and Three-Line Railing

Most railing lines are generally utilized as either two or three-line installations. In rare instances, a fourth line will be added for stylistic effect. Some manufacturers, installers, or end-users may change up the terminology a bit instead of using the number-line format. A key example is referring to three-line railing as railing with a “double top-rail” as opposed to three-line. Additionally, a one-line railing is much more commonly referred to as a handrail as that is the only viable use for such an item.


Any railing systems where top/bottom railing differs from the infill material, direction, or size will typically adhere to the above guidelines. However, when the infills of a railing are the same as the top and bottom rail, each horizontal line is counted in the number-line format. At Superior Aluminum, Pipe Railing fits this bill. Each line of pipe railing is made of the same 1.5” Schedule 40 pipe, meaning all horizontal runs are counted in the number-line format.

Showcasing pipe railing lines and how they are countedEach Horizontal Line is Noted on Pipe Railing


The amount of “lines” in a given railing system is just one of many factors affecting the overall design. However, railing lines are an extremely critical element of the project overall. Changing the number of lines can dramatically affect the overall aesthetics of a project so it is important to understand the concept before placing an order.

If you still have questions about railing lines or railing design in general, please contact us or call 937-526-4065. If this has been the final piece of the puzzle you needed to pull the trigger, you can get a quote now!


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