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Handrail Extension at botom of stairs

S

slester

Member
Joined
Aug 30, 2013
Messages
1
Location
Delaware
Current IBC, NFPA 101, ANSI A117.1, and 2010 ADA require the stair handrail to extend one tread beyond the last riser. There is no longer the requirement for the additional 12" horizontal extension.

Can anyone provide background as to why this change was made?
 
Guidance on the 2010 ADA Standards for Accessible Design

http://www.ada.gov/regs2010/2010ADAStandards/Guidance2010ADAstandards.htm

2010 ADASAD Sections 505.10.2 and 505.10.3 of the 2010 Standards require handrail extensions at both the top and bottom of a flight of stairs. The requirement in the 1991 Standards that handrails extend horizontally at least 12 inches beyond the width of one tread at the bottom of a stair was changed in the 2004 ADAAG by the Access Board in response to public comments. Existing horizontal handrail extensions that comply with 4.9.4(2) of the 1991 Standards should meet or exceed the requirements of the 2010 Standards
 
The original intent was to assist with the decent based on forward momentum

Based on studies that it really did not help with falls and complaints, the extra extension was removed.
 
I'm not sure the horizontal extension is required in California anymore. See below. A horizontal extension looks like only one of several options... what do you think?

CBC 2013:

11B-505.10.3 Bottom extension at stairs. At the bottom

of a stair flight, handrails shall extend at the slope of the

stair flight for a horizontal distance equal to one tread

depth beyond the last riser nosing. Such extension shall

continue with a horizontal extension or shall be continuous

to the handrail of an adjacent stair flight or shall

return to a wall, guard, or the walking surface. At the bottom

of a stair flight, a horizontal extension of a handrail

shall be 12 inches ( 305 mm) long minimum and a height

equal to that of the sloping portion of the handrail as measured

above the stair nosings. Extension shall return to a

wall, guard, or the landing surface, or shall be continuous

to the handrail of an adjacent stair flight.
 
JBJ707

California does not have very good code writers and unfortunately refuse to use the style manuals that ICC and legacy code orgs used for so long. In order to get where you need to go for handrail extensions, you need to wind through all conditions stated in all the handrail sections to compile what is applicable. I.E. if you are at a stair switchback, then the rail extension is satisfied by the "or" for continuous to the handrail of adjacent stair flight since the other code section mandates a continuous handrail for the stair switch back. So in a lot of cases, the "or" is what will govern but must be part of a code section directly addressing the condition. (went to DSA training a while ago) WHEW!!!
 
jdfruit,

Thank you for your response. I understand what you are saying, but I'm not finding anything in the code that would require that I add the additional 12" horizontal extension at the bottom of a flight of stairs- other than figure 11B-505.10.3. It appears that the additional 12" horizontal extension after the sloped extension is just one of several options given by the language of the section above. For example, I have a sloped handrail extend past the last riser for the length of one tread, and then I shall either: 1. continue with a horizontal extension, OR 2. have the handrail be continuous to the handrail of an adjacent stair, OR 3. return the handrail to a wall or guard, OR 4. return the handrail to the walking surface.

Even CBC section 1012.6 "Handrail extensions" states: "Where handrails are not continuous between flights, the handrails shall extend horizontally at least 12 inches (305 mm) beyond the top riser and continue to slope for the depth of one tread beyond the bottom riser." with no mention of a horizontal extension beyond the sloped extension at the bottom of the flight.

Now I've been designing for an extra 2+ feet at the bottom of a run of stairs for years to account for both the sloped extension and horizontal extension as shown in the figure, and I wouldn't design a new stairway in a new building otherwise. But I'm in a situation in an existing building where I'm trying to fit in a few steps up to an existing platform, and the bottom horizontal extension is killing me due to space constraints. (already installing a sloped pathway to the platform on the other side of the room)
 
You can parse it any way you want; however the stated intent by DSA when proposing the 2013 CBC amendments was to not make any changes in content or intent with no enhancements or reductions compared to the 2010 CBC. The handrail horizontal extensions were required in the 2010 and are still required in the 2013.

If you extract this statement from 11B-505.10.3 (italics indicate the CA inserted language) the handrails are clearly required to extend horizontally.

...At the bottom of a stair flight, a horizontal extension of a handrail shall be 12 inches (305 mm) long minimum and a height equal to that of the sloping portion of the handrail as measured above the stair nosings. ...
 
See, I read that as either 1. a qualifier for IF one uses a horizontal extension, or 2. horizontal extensions are required.

You are absolutely right that California has terrible code writers.

I'll have to go with the most strict reading until a judge weighs in, or someone who can write clearly adjusts this language. (which will never happen...)

Thanks again-
 
As per the ANSI A117.1-1998, it would appear that the language never required this additional 12” horizontal extension, it only stated “If provided” then it had to meet the requirements as noted in that section. This all went away in the ANSI A117.1-2003 Standard:

ANSI A117.1-1998 505.10.3 Bottom Extension at Stairs. At the bottom of a stair flight, handrails shall extend at the slope of the stair flight for a horizontal distance equal to one tread depth beyond the last riser nosing. Such extension shall continue with a horizontal extension or shall be continuous to the handrail of an adjacent stair flight or shall return to a wall, guard, or the walking surface.

If provided

at the bottom of a stair flight, a horizontal extension of a handrail shall be 12 inches (305 mm) long minimum and a height equal to that of the sloping portion of the handrail as measured above the stair nosings….
 
What are you California jurisdictions requiring? I would love to eliminate the horizontal projection required in Chapter 11 and go with 1012.6.
 
Here is the CBC for stair handrails with the added CA language for the 12" horizontal extension required. The extension has been kept in the CA code as compared to ANSI & 2010 ADA that have eliminated the 12" horizontal extension.

11B-505.10.3 Bottom extension at stairs. At the bottom of a stair flight, handrails shall extend at the slope of the stair flight for a horizontal distance equal to one tread depth beyond the last riser nosing. ... At the bottom of a stair flight, a horizontal extension of a handrail shall be 12 inches (305 mm) long minimum and a height equal to that of the sloping portion of the handrail as measured above the stair nosings.
 
Revised language from July 1 2015 CBC Supplement:

11B-505.10.3 Bottom extension at stairs. At the bottom of a stair flight, handrails shall extend at the slope of the

stair flight for a horizontal distance equal to one tread depth beyond the last riser nosing. The horizontal extension

of a handrail shall be 12 inches (305 mm) long minimum and a height equal to that of the sloping portion of

the handrail as measured above the stair nosings. Extension shall return to a wall, guard, or the landing surface, or

shall be continuous to the handrail of an adjacent stair flight.

Looks like they really want those 12" horizontal extensions. I guess it only amounts to a surcharge of a minimum of 4 extra s.f. of building area at the bottom of every stair run in the state. That's a lot of extra square feet statewide - think of all the construction jobs created by this one code detail! /sarcasm
 
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