I am installing an interior railing next to a set of stairs. I am capturing the balusters between the upper rail and a lower rail. When researching how high I can install the lower rail, all I see our references to exterior deck railings, which require that the space can be no more than the space through which a 6 inch ball could pass. Is this requirement true for an interior stair rail as well?
Thanks, Mark
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Replies
4"
It's 4 inches. I don't know where it says 6" any more, even for exterior. It used to be 9" but a kid could fall through that. Then it was 6" but a kid could get its head stuck. Check, but the height might now bee 42".
Thanks ... I’ll check with the inspectors.
Height
42" would be the height of a guard rail. A stair hand rail does not have to be that high. 34 - 36 if I'm not mistaken.
Mark
bestt bet is contacting your local inspection office.
but here is a diagram I found which says less than a 6” sphere can pass through.
Of course, the copy won’t make it here.
we've worked on the less than 6” sphere rule at the largest part of the triangle under the guardrail portion of a stair tread. The sloping area under the bottom rail in a baluster top and bottom rail system.
.
Thanks ... I’ll give them a visit tomorrow.
Check the IRC. Just to be clear, there is a difference between a hand rail and a security rail.
Check the IRC. Just to be clear, there is a difference between a hand rail and a security rail.
IRC Stair Building Code (2006) didn't specifically address your application but as Calvin stated it did address your bottom rail when it was installed on a set of stairs and it was 6 inches. Besides checking the IRC code your local inspector will be able to tell you if your location uses the IRC or a State/location variance. Not all states/locations follow the IRC.
My sincere thanks to all of you who responded. I didn’t get the chance to call the inspectors today, but I plan to connect with them tomorrow and let you know what I find out about which code is used, and what the code says as far as the opening and the height of the top rail.
Here...
handrail 34-38” .
Come to think of it.
If the bottom rail slopes, I think there is an exception to the 4" rule below the rail on the riser side of the tread. It would be hard to make the balustrade other wise.
A guard requirement is different from that of a hand rail and the confusion is when both functions are combined on stairs. The height of a hand rail can be from 34" to 38" and personally I would go with 34". Different requirements though for a guard rail which needs to be 42" above the stair tread.
The maximum clearance is measure between the balusters is 4" and you can avoid problems with the step rail to tread gap by not having the lower rail at all but instead having the balusters go all the way to the tread from the top rail - so long as you don't have fully carpeted stairs.