• Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by first logging in then clicking here: Upgrades

How long is a stair handrail extension when there's only one riser / no tread?

Y

Yikes

Gold Member
Joined
Nov 2, 2009
Messages
3,063
Location
Southern California
ADAS / CBC 11B-505.10.3 requires the handrail to extend at the slope of the stair flight for a horizontal distance equal to the tread depth beyond the last riser nosing.

But what do you do when your stair is essentially not a "flight" because there is no "tread"; only top and bottom landings with one single riser in between?
Are any handrails required at all? If "yes", then are only the horizontal/level extensions required? - - and if so, is there any sloping part at all?
 
Last edited:
Yikes,

Definitions:
  • FLIGHT: A continuous run of rectangular treads and winders or combination thereof from level to another.
  • STAIR: A change in elevation, consisting of one or more risers.
  • STAIRWAY: One or more flights of stairs, either interior or exterior, with the necessary landings and connecting platforms to form a continuous and uninterrupted passage from one level to another.
1011.11 HANDRAILS, Flights of Stairways shall have handrails on each side and ...

Clearly the location in question is a "Stair" as a landing - Riser - Landing, includes one riser.

IF you have a flight of stairs leading to a landing, to a single riser, to a lower landing. The continuous run over the single riser is part of the stairway, is it not.

Then there are those that contend that a single riser is not a flight and no handrail required,

however, you need to look at exception 2. which clearly spells out when a single change in elevation is not required to have a handrail. If your location does not meet the exception or another exception, then handrails are required.

As to the design configuration that is simple.

The upper landing requires the minimum 12-inch handrail extension. As to the lower, it would be the same as if there was a tread in-between, as thus a minimum of 11-inch tread depth or more (the minimum). The sloped section needs to at least meet a 11-inch tread depth slope for the riser outward.

The other options are to decrease the pitch and extend further outward, but not level.
 
Thanks, tbz.
1011.11 exception #2 is for "walkways". In California Building Code 202 there is no definition of "walkway", but the definition of "walk" implies an exterior condition.
1651780031068.png
The riser in question is an interior condition. But it does have landings that exceed minimum length requirements.

When you say: "As to the lower, it would be the same as if there was a tread in-between", is that an inference? How would that be deduced from 505.10.3?
 
So,

I am envisioning the following at your location of 2 landings with a single riser and then the handrail elevation below complies with 2010 ADA and the model IBC, which I believe because of ADA, CBC follows without modification.

The 12" upper landing is per 505.10.2

The superimposed minimum tread depth with ? on riser height, I used 7" maximum, provides you the slope of a compliant handrail, per 505.10.3.

The visually impaired advocates, don't like the old way of leveling off and running an additional 12" on the lower.

But this is what is done and required. As noted before, if a handrail was not required for a single riser between landings, then no need for exception 2 in the IBC 1011.11.


HR1R.jpg
 
bill1952 said:
or this? (assuming correct dimensions):
View attachment 8934
Click to expand...

Bill that is not a compliant handrail,

IBC 1014.6 Handrail extensions.

Handrails shall return to a wall, guard or the walking surface or shall be continuous to the handrail of an adjacent flight of stairs or ramp run.

The pointed ends as shown are not compliant handrail extensions.
 
And lets not forget to go back to: Is the single riser allowed?

1003.5 Elevation change. Where changes in elevation of less
than 12 inches (305 mm) exist in the means of egress, sloped
surfaces shall be used. Where the slope is greater than one
unit vertical in 20 units horizontal (5-percent slope), ramps
complying with Section 1012 shall be used. Where the difference
in elevation is 6 inches (152 mm) or less, the ramp shall
be equipped with either handrails or floor finish materials
that contrast with adjacent floor finish materials.
Exceptions:
1. A single step with a maximum riser height of 7
inches (178 mm) is permitted for buildings with
occupancies in Groups F, H, R-2, R-3, S and U at
exterior doors not required to be accessible by
Chapter 11.
2. A stair with a single riser or with two risers and a
tread is permitted at locations not required to be
accessible by Chapter 11 where the risers and treads
comply with Section 1011.5, the minimum depth of
the tread is 13 inches (330 mm) and not less than
one handrail complying with Section 1014 is provided
within 30 inches (762 mm) of the centerline of
the normal path of egress travel on the stair.
3. A step is permitted in aisles serving seating that has
a difference in elevation less than 12 inches (305
mm) at locations not required to be accessible by
Chapter 11, provided that the risers and treads comply
with Section 1029.13 and the aisle is provided
with a handrail complying with Section 1029.15.
 
tbz said:
Bill that is not a compliant handrail,

IBC 1014.6 Handrail extensions.

Handrails shall return to a wall, guard or the walking surface or shall be continuous to the handrail of an adjacent flight of stairs or ramp run.

The pointed ends as shown are not compliant handrail extensions.
Click to expand...
Not quite on topic but I'd it same in IRC?
 
You must log in or register to reply here.
Top