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Horizontal Bar Spacing Guide
Space horizontal bars so the opening between them stays under 4 inches. With our 5/8″ round horizontal bars, that means 7 to 9 bars on a stair and 9 to 11 bars on a balcony, depending on how far apart your newel posts are. The tables and diagram below show exactly how many bars to use.
Balcony and Landing Spacing (42″ Railing)
| Newel posts spaced | Bars | Opening between bars | Bar spacing (on center) |
|---|---|---|---|
| Under 6 ft | 9 bars | 3-1/2″ | 4-1/8″ |
| Under 7 ft | 10 bars | 3-1/8″ | 3-3/4″ |
| Under 8 ft | 11 bars | 2-3/4″ | 3-7/16″ |
Stair Spacing (36″ Railing, 40° Rake)
| Newel posts spaced | Bars | Opening between bars |
|---|---|---|
| Under 6 ft | 7 bars | 3-1/2″ |
| Under 7 ft | 8 bars | 3″ |
| Under 8 ft | 9 bars | 2-9/16″ |
Why more bars when newels are farther apart? The farther apart your newel posts are, the more a horizontal bar can flex in the middle. Closer bar spacing on longer runs keeps the openings under 4 inches even when someone leans on the railing.
What This Guide Is Based On
- Handrail: RO-6084 handrail (1-5/8″ tall)
- Bars: 5/8″ diameter round horizontal bars
- Stair: 36″ handrail height at a 40-degree rake
- Balcony: 42″ handrail height
- Inspection: passes the 4-inch sphere test
Your numbers may change with a different handrail height, stair angle, handrail profile or newel spacing, or if you use stabilizer newels. If your stair is different, send us your measurements for a free quote and we’ll work out the spacing for you.
Horizontal Bar FAQ
How far apart should horizontal bars be spaced?
Close enough that the opening between bars stays under 4 inches. With 5/8″ bars, that’s about 3-7/16″ to 4-1/8″ on center on a balcony, depending on newel spacing.
How many horizontal bars do I need on a stair?
With a 36″ railing at a 40-degree rake, plan on 7 bars when newels are under 6 feet apart, 8 bars under 7 feet, and 9 bars under 8 feet.
How many horizontal bars do I need on a balcony?
With a 42″ railing, plan on 9 bars when newels are under 6 feet apart, 10 bars under 7 feet, and 11 bars under 8 feet.
Are horizontal bar railings allowed by building code?
In most areas, yes, as long as they pass the 4-inch sphere test. Some local codes restrict horizontal infill because children can climb it, so check with your local building inspector before you install.