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Solid Riser Definition

A

ADAguy

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The dictionary defines solid as without (openings?) or not?

As to commercial stairs may solid risers in fact be made of perforated (opening size limited to "x") metal or horizontal bars with spaces between, as allowed alternate methods and means where the underside of the stair is not required to be protected or the building is sprinklered?
 
While running down a stairway that may or may not be on fire, I prefer that the flames not nip at my ankles, how bout you?

Did I forget about smoke and the zombies below the stairs?

I know that's not the answer your looking for!
 
ANSI A117.1

504.4 Tread Surface.

Stair treads shall comply with Section 302 and shall have a slope not steeper than 1:48.

302.3 Openings.

Openings in floor surfaces shall be of a size that does not permit the passage of a 1/2 inch (13 mm) diameter sphere, except as allowed in Sections 407.4.3, 408.4.3, 409.4.3, 410.4, and 805.10. Elongated openings shall be placed so that the long dimension is perpendicular to the predominant direction of travel.

Not as much to do with fire as it has to do with high heels, crutches, and walking canes getting caught in the surface openings.

Ski resorts are primary example where solid treads are more of a hazard then steel grated treads
 
Nice try mt but I an referring to "vertical" surfaces of risers; I know of tread and floor surfaces.

Residential specifically addresses it but commercial uses the word "solid" and fails to provide a clarifying definition.
 
In a commercial application I've seen no risers what so ever. One set of stairs had only one stringer in the middle, it was artistic. The local county government building stairs have open risers.

Stair wells I've used have had open risers. So unless there's been a code change or the occupancy requires the risers to be closed, I think your a go!
 
Solid risers are required to prevent feet, canes, crunches excetra from getting stuck and tripping individuals.

they are now required in commerial and multifamily projects that use the stair as a means of egress. Started out in the chapter 11. Later moved to chapter 10.
 
1009.7.5.3 Solid risers.

Risers shall be solid.

Exceptions:

1. Solid risers are not required for stairways that are not required to comply with Section 1007.3, provided that the opening between treads does not permit the passage of a sphere with a diameter of 4 inches (102 mm).

2. Solid risers are not required for occupancies in Group I-3 or in Group F, H and S occupancies other than areas accessible to the public. There are no restrictions on the size of the opening in the riser.

3. Solid risers are not required for spiral stairways constructed in accordance with Section 1009.12.

4. Solid risers are not required for alternating tread devices constructed in accordance with Section 1009.13.
 
As I've previously noted mt, my question is for commercial "B" occupancies, not residential.

Mark is on point but I stlll need to know if perforated metal can be used for risers vs solid material.
 
1009.7.5.3 Solid risers.Risers shall be solid.

Exceptions:

1. Solid risers are not required for stairways that are not required to comply with Section 1007.3, provided that the opening between treads does not permit the passage of a sphere with a diameter of 4 inches (102 mm).

2. Solid risers are not required for occupancies in Group I-3 or in Group F, H and S occupancies other than areas accessible to the public. There are no restrictions on the size of the opening in the riser.

3. Solid risers are not required for spiral stairways constructed in accordance with Section 1009.12.

4. Solid risers are not required for alternating tread devices constructed in accordance with Section 1009.13.
Click to expand...
I think that this code section needs work. Stairs should never be an open riser and the four inch sphere is way too large. The op asked if horizontal bars with spaces between is legal and it is as long as a 4" sphere won't pass through. 2" is all that you need to trap feet.
 
There are 2 different issues/concerns with open risers. Most of the replies have focused on the H/C aspect, and for commercial occupancies that is probably the greater concern.

In residential settings, more specifically ResCode buildings, it has more to do with entrapment and children getting hurt.
 
1007.3 is accessible MOE, based on that I would agree with MT citing the ANSI requirement...It's not super clean, but if it is good for the tread, it is good for the riser....
 
Given the circumstances, stairs can be functional (a means of safe vertical access/egress) elements and/or works of sculpture, art or whimsy (no risers or handrails) used in either commercial or residential applications; in either case they are subject to both prescriptive and performance (based on common sense/best practices or not) requirements.

Where the requirements lack clarity (definition of solid?) it remains for the AHJ to determine if solid means (without "any" openings, or not).
 
ADA [h=5]504 Stairways[/h] 504.1 General. Stairs shall comply with 504.

504.2 Treads and Risers. All steps on a flight of stairs shall have uniform riser heights and uniform tread depths. Risers shall be 4 inches (100 mm) high minimum and 7 inches (180 mm) high maximum. Treads shall be 11 inches (280 mm) deep minimum.

504.3 Open Risers. Open risers are not permitted.

A designer has to meet all applicable regulations. A building department can approve a riser with openings limited to the passage of a 4" sphere and the design would be a civil rights violation if the stair is a means of egress stair or on an accessible route.

ICC/ANSI

504.3 Open Risers.

Open risers shall not be permitted.
 
The 4" sphere limitation is to prevent toddlers from sliding between the steps (or off the side of the steps). There's nothing to prevent them from rolling backwards down the stairs.

A secondary reason for solid risers is because some people get nervous looking through open risers on high stairs.

ADA limits the slope of a riser to 30 degrees from vertical, so that people with leg braces won't get their feet caught.

Risers with small (1/4" - 1/2") perforations shouldn't present any dangers on 1 or 2 story stairs.
 
As understood Paul, it comes down to the AHJ accepting (or rejecting) use of perforated material (based on maximum size of openings not exceeding (<4"), the smaller the better.
 
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