Bar spacing is a crucial element in wrought iron work. There are two main approaches, and neither is inherently right or wrong. The “fixed” spacing method is faster and simpler to execute. On the other hand, the “variable” or “justified” spacing takes more time but results in a more polished and visually appealing finish.
Fixed spacing method
This is one of the most common methods used by online suppliers of wrought iron railings. Typically, website descriptions mention a 100mm spacing between bars or bars spaced at 100mm. This means there is a 100mm gap between each upright bar. While this sounds straightforward, it can lead to issues. Specifically, the gap between the wall and the first upright bar, as well as between the last upright bar and the wall, may not be 100mm.
In fact, the gap between the wall and end bars depends heavily on the length of the metal railing. It results from the leftover space after calculating the railing gaps. This gap will never exceed 100mm and is typically smaller.
Why use this method of spacing? The answer is simple: speed of construction. With a bit of skill, the right tools, and some time, you can easily create a spacing tool. This tool lets you quickly and easily position cut upright bars, making them ready to weld without any complex calculations. Just ensure that the end bars have equal gaps relative to each other. Making a high quality and accurate spacing tool takes time. But once made it can be used over and over again to produce consistently accurate spacing between upright bars
This also provides access to pre-manufactured parts, many of which are designed for use in a 100mm gap. Components such as scrolls and rings, being pre-manufactured, are more affordable than custom-made parts. Therefore, the fixed spacing method is clearly the most cost-effective option.
Variable or justified spacing method.
This method is significantly slower because it requires manually marking the position of every upright in the wrought iron railing. Essentially, you determine the maximum acceptable gap between uprights, then use calculations to find the exact spacing. For example, instead of a 100mm gap, you might end up with 96mm, depending on the length of the railing. But this gap will be constant from the wall to the first upright and all the way through, with the same gap at the end. This variability makes it impossible to create a standard gap tool for the bars, resulting in a much longer construction time compared to using fixed spacing.
Visually, it appears far more impressive than fixed spacing, and you often exclude pre-manufactured parts simply because your gap ends up less than 100mm. The biggest downside, of course, is the significantly increased construction time—often by as much as 50%. It’s perfection, but it comes at a cost.