Stair balluster spacing

Does stair balluster spacing vary within your County/State. I contacted the building department where I live in California and they told me maximum width was 4-3/8" wide. I always thought it was 4" as I was taught. Also did any of this change as the years went on?

The spacing in 4 3/8" on stairs and 4" on railings/guards around here.

If I understand you correctly, anywhere there is a stair tread and riser the spacing can be 4–3/8" wide and guards such as upper landings, hallway guards its 4" wide max.

Correct. :slightly_smiling_face::upside_down_face:

Thank you so much. It can be quite confusing. Just curious where do you practice your craft?

I’m retired in NW MI.

What’s interesting is that the building department did not elaborate or explain that bit of information.

Thank you sir!

My pleasure.

That’s why we have jobs :slight_smile:

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Not in the least unusual.

Larry Kage’s comment is excellent as well.

This is a great graphic.


Thank you sir, for the info. I appreciate it.

This is always a sore subject of mine. I don’t remember exact time frame the standard of a 36" railing was implemented. There are a lot of homes built in the late 70’s and into the 80’s, Contemporary farmhouse was very popular style in Chester County. They were built with open floor plans, two story foyers with catwalk hallway connecting master suite to rest of the bedrooms, these have 32" high railings with spindles set at 6" centers. Spindles/pickets are finished sized 1.5 x 1.5, so spacing ends up at 4.5" opening. Disturbing to be upstairs with that 32" railing and that little extra spacing. Extra 4" height of a 36" railing may not seem like it should be such a big deal but at 6’-2", I can tell you it’s a little unsettling.



Good one, Roy!

The time frame doesn’t actually matter since you’re calling out a safety issue. I include something that says it may have been OK at the time of original construction, and homes don’t have to be updated to meet newly-enacted building codes, but it would not be allowed in a new home for safety reasons. Recommend updating in a manner consistent with modern safe practices by a qualified contractor.
“…in a manner consistent with modern safe practices…” keeps you well away from the word “code” or even “standards”, which some people (attorneys or judges) might think implies “building code”.