# theater aisle



## spector51 (Dec 22, 2014)

View attachment 2110


So, this configuration just does not pass the eye test but am having a hard time citing a code section or finding an actual violation.  Theater owner has had several employees and patrons hurt at the stairs.  Any here have any ideas?  This was built under the 2006 IBC.Thanks
	

		
			
		

		
	

View attachment 2110


/monthly_2014_12/572953f25233f_theatrestairs.jpg.aaf9f868857af88697529e66374deadf.jpg


----------



## cda (Dec 22, 2014)

not a stair person, but looks like it needs a step coming off the step!!!

Code section for regular stair drop??


----------



## steveray (Dec 22, 2014)

Other than you typical stair sections.....

1025.11 Assembly aisle walking surfaces.

 Aisles with a slope not exceeding one unit vertical in eight units horizontal (12.5-percent slope) shall consist of a ramp having a slip-resistant walking surface. Aisles with a slope exceeding one unit vertical in eight units horizontal (12.5-percent slope) shall consist of a series of risers and treads that extends across the full width of aisles and complies with Sections 1025.11.1 through 1025.11.3.

1025.11.1 Treads.

 Tread depths shall be a minimum of 11 inches (279 mm) and shall have dimensional uniformity.

Exception: The tolerance between adjacent treads shall not exceed 0.188 inch (4.8 mm). 1025.11.2 Risers.

 Where the gradient of aisle stairs is to be the same as the gradient of adjoining seating areas, the riser height shall not be less than 4 inches (102 mm) nor more than 8 inches (203 mm) and shall be uniform within each flight.

Exceptions: 1.   Riser height nonuniformity shall be limited to the extent necessitated by changes in the gradient of the adjoining seating area to maintain adequate sightlines. Where nonuniformities exceed 0.188 inch (4.8 mm) between adjacent risers, the exact location of such nonuniformities shall be indicated with a distinctive marking stripe on each tread at the nosing or leading edge adjacent to the nonuniform risers. Such stripe shall be a minimum of 1 inch (25 mm), and a maximum of 2 inches (51 mm), wide. The edge marking stripe shall be distinctively different from the contrasting marking stripe.

2.   Riser heights not exceeding 9 inches (229 mm) shall be permitted where they are necessitated by the slope of the adjacent seating areas to maintain sightlines.

That is going to suck to fix....


----------



## cda (Dec 22, 2014)

1. Who approved it??

2. Have the seats been changed since first approval??

Know of a few theaters that have up graded seating??? Could have thrown it off


----------



## spector51 (Dec 23, 2014)

Is the Aisle the stairs themselves or the individual row of seats.  The definitions provided in the code don't seem to help.  The riser heights are uniform and only 7 inches.


----------



## cda (Dec 23, 2014)

spector51 said:
			
		

> Is the Aisle the stairs themselves or the individual row of seats.  The definitions provided in the code don't seem to help.  The riser heights are uniform and only 7 inches.


Where does the code say a stair ends??

Plus leaving the seats is the exit access

Where do stairs end:::

https://ixquick-proxy.com/do/spg/show_picture.pl?l=english&cat=pics&c=pf&q=Round+stairs&h=768&w=1024&th=120&tw=160&fn=Patio-26.jpg&fs=479.3%20k&el=boss_pics_2&tu=http:%2F%2Fts2.mm.bing.net%2Fth%3Fid%3DHN.608027409421107597%26pid%3D15.1%26H%3D120%26W%3D160&rl=NONE&u=http:%2F%2Fcut-above.com%2F2011%2F06%2Fpatio-26%2F&udata=215b53c8115e9f6bd85b396609ab2d86&rid=LGLOLTNOTSTR&oiu=http:%2F%2Fcut-above.com%2Fwp-content%2Fuploads%2F2011%2F06%2FPatio-26.jpg


----------



## RLGA (Dec 23, 2014)

The "aisle" is the one with the steps and the "aisle accessway" is the row of seating.  I've looked at both the 2012 and 2015 IBC and there is no provision that specifically addresses this condition where the aisle accessway meets the aisle.  However, logic would dictate this is not a good situation.  Sounds like a candidate for code change proposal.


----------



## cda (Dec 23, 2014)

RLGA said:
			
		

> The "aisle" is the one with the steps and the "aisle accessway" is the row of seating.  I've looked at both the 2012 and 2015 IBC and there is no provision that specifically addresses this condition where the aisle accessway meets the aisle.  However, logic would dictate this is not a good situation.  Sounds like a candidate for code change proposal.


No step down or step up max hieght??

Seems like it is a contiuation of the steps?


----------



## cda (Dec 23, 2014)

no help:::???

1028.11.1 Treads. Tread depths shall be a minimum of 11 inches (279 mm) and shall have dimensional uniformity.

Exception: The tolerance between adjacent treads shall not exceed 3/16 inch (4.8 mm).

Depths of treads are not to be less than 11 inches (279 mm) and uniform throughout each flight, except that a variance of not more than 3/16 inch (4.8 mm) is permitted between adjacent treads to accommodate variations in construction. While this provision is the same as the limiting dimension for treads in interior stairways (see Section 1009.3), it rarely applies in the construction of stepped aisles. A more common form of stepped aisle construction is to provide a tread depth equal to the back-to-back distance between rows of seats. This way the treads can be extended across the full length of the row and serve as a supporting platform for the seats. Other arrangements might require two treads between rows of seats.

In theaters, for example, the back-to-back distance between rows of fixed seats usually ranges some-where between 3 and 4 feet (914 and 1219 mm), depending on seat style and seat dimensions as well as the ease of passage between the rows (see Figure 1028.11.1). The selection of single-tread or two-tread construction between rows of seats depends on the gradient and suitable riser height (see Section 1028.11.2), as needed for sightlines.

In comparing this section with Section 1028.11.2, it is significant to note the emphasis placed on the tread dimension. While not desirable, the code permits riser heights to deviate; however, tread dimensions must not vary beyond the 0.188-inch (4.8 mm) tolerance.

1028.11.2 Risers. Where the gradient of aisle stairs is to be the same as the gradient of adjoining seating areas, the riser height shall not be less than 4 inches (102 mm) nor more than 8 inches (203 mm) and shall be uniform within each flight.

Exceptions:

1. Riser height nonuniformity shall be limited to the extent necessitated by changes in the gradient of the adjoining seating area to maintain adequate sightlines. Where nonuniformities exceed 0.188 inch (4.8 mm) between adjacent risers, the exact location of such nonuniformities shall be indicated with a distinctive marking stripe on each tread at the nosing or leading edge adjacent to the nonuniform risers. Such stripe shall be a minimum of 1 inch (25 mm), and a maximum of 2 inches (51 mm), wide. The edge marking stripe shall be distinctively different from the contrasting marking stripe.

2. Riser heights not exceeding 9 inches (229 mm) shall be permitted where they are necessitated by the slope of the adjacent seating areas to maintain sightlines.

In stepped aisles where the gradient of the aisle is the same as the gradient of the adjoining seating area, riser heights are not to be less than 4 inches (102 mm) nor more than 8 inches (203 mm) (see Figure 1028.11.2). For the safety of the occupants, risers should have uniform heights, where possible, throughout each flight of steps. However, nonuniformity of riser heights is permitted in cases where changes to the gradient in the adjoining seating area are required because of sightlines and other seating layout considerations.

Where variations in height exceed 3/16 inch (4.8 mm) between adjacent risers, a distinctive marking stripe between 1 and 2 inches (25 and 51 mm) wide is to be located on the nosings of each tread where the variations occur as a visual warning to the occupants to be cautious. Frequently, this is done with "runway" lights. Note that this stripe must be different from the tread contrast marking stripes required in Section 1028.11.3. These stripes must be visible in lighted conditions; therefore, these stripes are not required to comply with the provisions for luminous tread markings in Section 1024.

In comparing this section with Section 1028.11.1, it is significant to note the emphasis placed on the tread dimension. While not desirable, the code permits riser heights to deviate; however, Section 1028.11.1 does not permit tread dimensions to vary beyond the 3/16-inch (4.8 mm) tolerance.

1028.11.3 Tread contrasting marking stripe. A contrasting marking stripe shall be provided on each tread at the nosing or leading edge such that the location of each tread is readily apparent when viewed in descent. Such stripe shall be a minimum of 1 inch (25 mm), and a maximum of 2 inches (51 mm), wide.

Exception: The contrasting marking stripe is permitted to be omitted where tread surfaces are such that the location of each tread is readily apparent when viewed in descent.

The exception provides for the omission of the contrasting marking stripe where the tread is readily apparent such as when aisle stair treads are provided with a roughened metal nosing strip or where lighted nosings occur. In this situation, the user is aware of the treads without the marking stripe. This stripe must be different from the marking stripe required for nonuniform risers in Section 1028.11.2, Exception 1.

These stripes must be visible in lighted conditions; therefore, these stripes are not required to comply with the provisions for luminous tread markings in Section 1024.


----------



## RLGA (Dec 23, 2014)

I've noticed that the 2015 IBC has introduced Section 1029.10 "Transitions," which address transitions between stairways and stepped aisles, and Section 1029.9.7, which addresses stairways connecting to stepped aisles. The latter section refers to aisles that have stairways that connect to a cross aisle, but the situation that is presented to us is not an aisle, but an aisle accessway.  The language in Section 1029.10 is very confusing, but could be used in regard to this situation.  This section allows a transition between stairways in straight-run aisles.  The transition requires a minimum of 22 inches.  However, many aisle accessways have a width that is less than 22 inches, and requiring a 22-inch minimum width may be impractical for the slope of the seating.

I'm considering a proposal for a code change.  How's this:

"*1029.10.2.3 Transitions at aisle accessways.* Transitions at _aisle accessways_ where the required width of the _aisle accessway_ is less than 22 inches, the transition shall not be less than the required _aisle accessway_ width."

with this added exception to 1029.13.2.1 ...

"Exceptions:

  "1. [Keep existing exception]

  "2. Where _aisle accessways_ lead to the _aisle_, the tread depths shall extend the full width of _aisle accessways_.  Provide markings for extended treads in accordance with Section 1029.10.3."


----------



## Pcinspector1 (Dec 23, 2014)

That is a pretty wide aisle access-way IMO, it appears to me the seat has been moved back away from the second step creating the double step issue.

I always have to stand up at the movie theater to allow someone to get by me because of poor leg room.

RLGA's proposal may take a seat away for a wrap-around step? But would make it safer and the handrail would not require a modification if only dealing with the two steps.

pc1


----------



## tbz (Dec 23, 2014)

I would check the original plan for the seating layout.  It looks like they changed the seats to make VIP chairs, did it remove space from behind?

Also is there access from the side that you are not showing and did they use this aisle to make removable seating for ADA compliance that has brought about more than a few of these step problems.  Most of the time a removable glass guard panel is installed allowing for someone to look through but keeps people inline from taking the fall.


----------



## cda (Dec 23, 2014)

So if you come down a stair and have to take a right turn to exit, there is no maximum drop before another step is required?


----------

