Not sure why. But I'm having a hard time interpreting Intermediate Handrails

[CAR]

2018 Building Codes Illustrated:

"1014.9 Intermediate handrails. Where the occupant load served by a stairway becomes
significant, additional handrails may be necessary to assist stair users. The requirement is
based on the required capacity of the stair established by Section 1005.3.1, not the actual width,
and mandates that at no point shall the required capacity or minimum width be more than
30 inches (762 mm) from a handrail. See Figure 1014-9. It is difficult to determine the exact
point at which intermediate handrails are required, as the handrail projection into the required
width can vary from one design to the next. It should be noted that the measurement is to be
taken in regard to the handrail location, which is permitted to extend a maximum of 4½ inches
(114 mm) into the required width. Where the maximum encroachment occurs on each side
of the stairway, an intermediate handrail must be provided where the required width exceeds
69 inches (1,752 mm). A lesser required width would apply where the handrails do not extend
the full 4½ inches (114 mm) into the minimum required stairway width. As an additional safeguard
for wide monumental stairs, the handrails must be located along the anticipated travel
path of the stair users."

I'm working on an existing plaza project and we're redoing the stairs, redesigning a portion of the plaza as well. When I read this chapter, I'm not quite understanding, for example, If I have a 16'-8" exterior stair from the sidewalk level to the plaza level. How many intermediate handrails would I need?

 

[e hilton]

The requirement is
based on the required capacity of the stair not the actual width,
and mandates that at no point shall the required capacity or minimum width be more than 30 inches (762 mm) from a handrail.

Typical code obfuscation. Its based on capacity, but can’t be more than 30”.

 

[classicT]

You will need to determine the required width of the stairway per 1005.3.1 and provide sufficient handrails to achieve that required width. Only portions of the proposed stair that are within 30-inches of a handrail may be used to achieve that required width.

1005.3.1 Stairways
The capacity, in inches, of means of egress stairways shall be calculated by multiplying the occupant load served by such stairways by a means of egress capacity factor of 0.3 inch (7.6 mm) per occupant. Where stairways serve more than one story, only the occupant load of each story considered individually shall be used in calculating the required capacity of the stairways serving that story.​

i.e. - exterior handrails will get you 30-inches, intermediate handrails will net you 60-inches.


So, if your exterior stair is 16' 8" as indicated, and has (guesswork here) a rail at each edge of the stairs, and one in the middle, then you have a total of 120" of stairway that can be used as an accessible means of egress. 120" divided by 0.3-inches per occupant means that your stairs can handle 400 occupants.

 

[RLGA]

If this is just an outdoor space not associated with any building, then there is no requirement for intermediate handrails per the building code (unless there's another ordinance that requires them).

If the stairs are part of an exit discharge for a building, then, as previously mentioned, it is based on the occupant load from the building (or buildings if more than one) using that exit discharge pathway. Only the widths within 30 inches of a handrail can be counted toward the minimum required capacity.

For example, if the stairs have a width of 16'-8" (or 200 inches) and the occupant load they serve is 200, then you only need the two handrails that are required on each side of the stairs (30"/0.3" per occupant x 2 = 200). But if the occupant load is 400, then you would need to add an intermediate handrail, usable on both sides, that would provide another 60 inches of capacity, thus another 200 occupants.

 

[ADAguy]

For monumental stairs such as this the intermediate hand rail can then be to one side or the other, spaced at 60" on center, allowing for 30" of reach to either one when using them. Best practice would suggest that you install more than one intermediate for convience.

 

[redbird11]

OSHA says an intermediate handrail is required when the stair width is greater than 88".

OSHA does not mention occupant load. Which code wins, IBC or OSHA?

 

[RLGA]

The most restrictive would apply. However, OSHA only applies to workplaces, so most, but not all, building applications would fall under the OSHA Standards. Building departments do not enforce OSHA.

 

[mark handler]

 

[Inspector Gift]

ANSWER: 3 Intermediate handrails are required for a stairs width of 16'-8".


A handrail must be within 30 inches reach. The MAXIMUM DISTANCE BETWEEN HANDRAILS IS 60 INCHES.

Assuming the two (2) side handrails project a maximum of 4-1/2" into the stair width, and each of the intermediate handrails is 2 inches wide, two intermediate handrails work for a stairs of a maximum of 16'-1".

 

[RLGA]

ANSWER: 3 Intermediate handrails are required for a stairs width of 16'-8".


A handrail must be within 30 inches reach. The MAXIMUM DISTANCE BETWEEN HANDRAILS IS 60 INCHES.

Assuming the two (2) side handrails project a maximum of 4-1/2" into the stair width, and each of the intermediate handrails is 2 inches wide, two intermediate handrails work for a stairs of a maximum of 16'-1".

Only if the full width of the stairs is required for the indicated occupant load.

 

[Inspector Gift]

It is assumed that the 16'-8" stair width is the minimum required based upon occupant load.

 

[ADAguy]

As you have indicated then a minimum of (3) intermediates would then be required, yielding (4) equal spaces between HRs..