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Stairs - risers

I

Inspector Gadget

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Joined
Mar 5, 2020
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Location
New Brunswick
Morning. Wanted to touch base with my Canadian colleagues regarding open stair risers, and how .... committed other AHJs are with regards to enforcing the requirement for a closed riser.

I've been lenient on exterior stairs on homes, and on part 9 buildings without a ton of risers.

But I'm thinking of being more vigilant.
 
Public stairs I was always looking for 100%% compliance (obviously)

Private stairs, I was more lenient, only looking to ensure the openings were acceptable. Check out 9.8.4.9. in the 2020 for some guidance.
 
Inspector Gadget said:
Morning. Wanted to touch base with my Canadian colleagues regarding open stair risers, and how .... committed other AHJs are with regards to enforcing the requirement for a closed riser.

I've been lenient on exterior stairs on homes, and on part 9 buildings without a ton of risers.

But I'm thinking of being more vigilant.
Click to expand...
what is the article preventing open risers?
 
Mac Moonfire said:
what is the article preventing open risers?
Click to expand...

This is the thing... there's no article in NBC 2015 specifically preventing open risers in Part 9, and in fact, 9.8.8.5 has language specifically allowing open risers.

That said, in my view, the language of guards applies - if you're more than 60cm above grade, you have an opening >10cm that needs protecting.... It's a weak argument. I haven't made it.

As tmurray has pointed out, NBC 2020 has clarified the apparent *intent*. But we're not there yet in our jurisdiction.

Part 3 has a clear stance.
 
I let it go on residential, would push for closed risers on non-residential Pt9.
 
I am confused. Does the Canadian code allow open risers? Is that true in some locations and not in some locations? When you say that you “let it go” on residential but “push” for closed risers on non-residential…what exactly is code compliant?

Perhaps one of the Canadian members can clarify what is required where.
 
Open risers are not permitted on Part 3 buildings (think IBC) but is permitted on Part 9 buildings (like IRC but with small commercial as well). The question centers around if officials are enforcing guard requirements related to head entrapment on the riser spaces.
 
The stated requirement for Pt9 guards includes "flights of steps and ramps...", so I do not believe the intent is for the risers of individual stairs to be closed off.

It is kind of like the little open triangle formed by the tread, riser and bottom rail of the stair guard. It would allow the passage of a 4" sphere but in practice is never rejected.
 
Plumb-bob said:
The stated requirement for Pt9 guards includes "flights of steps and ramps...", so I do not believe the intent is for the risers of individual stairs to be closed off.

It is kind of like the little open triangle formed by the tread, riser and bottom rail of the stair guard. It would allow the passage of a 4" sphere but in practice is never rejected.
Click to expand...
9.8.8.1.
Except as provided in Sentence (2) and except at the leading edge at the top of a
flight, every surface to which access is provided, including but not limited to [emphasis added] flights of
steps and ramps, exterior landings, porches, balconies, mezzanines, galleries and raised
walkways, shall be protected by a guard on each side that is not protected by a wall for
the length where the difference in elevation is more than 600 mm between the walking
surface and the adjacent surface within 1.2m.

...I've rejected the triangular area...
 
IBC 1015.4 exception 2 allows a 6" sphere in the triangular area. Does the Canadian code have a similar exception?
 
The OP used the term closed riser. Is that one that a 4" sphere can't pass or is it solid?

Educate me: Are solid risers ever required?

Wanting to do an IRC stair with slightly less than 6" risers and 2" thick treads, for an open riser appearance.
 
IRC R311.7.5.1 limits openings in risers to one a 4" sphere can't pass through if the riser is more than 30" above the floor or grade below.

You should be OK with a full 2" thick tread, but would have to go down to a 5 1/2" riser if the tread is a 2 by (1 1/2" actual thickness).
 
Paul Sweet said:
IRC R311.7.5.1 limits openings in risers to one a 4" sphere can't pass through if the riser is more than 30" above the floor or grade below.

You should be OK with a full 2" thick tread, but would have to go down to a 5 1/2" riser if the tread is a 2 by (1 1/2" actual thickness).
Click to expand...
Thanks. I go to a mill to get it rough sawn and will plane it. I know riser will be under 6" - just not sure how many 16ths. I'm ignoring I probably can't cite where a 2"+ thick black walnut plank can span 38 or so inches for a stair tread, but the building inspector here is very "practical" and I'm unconcerned.

But is a "closed" riser a solid riser or one simply complying with the 4" where rule? Not picking on Inspector Gadget, just curious what that term means to most.
 
I've always taken open risers to mean anything that does not have a solid riser. So, even if the 4" sphere rule is passed, it would still be technically an open riser.

The code doesn't really define it one way or another though.
 
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