back to basics chapter 10 means of egress - … ibc chapter 10.pdf · 1 back to basics – chapter...

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BACK TO BASICS – CHAPTER 10 MEANS OF EGRESS

Presented at UMass, October 2013

Christopher R. Laux, A.I.A. Architect/Building Official/Consultant

Contact Information

Christopher R. Laux, A.I.A.

PO Box 636

Woodbury, CT 06798-0636

(203) 263-5787

[email protected]

Applicability of discussion

This discussion is based on the provisions of the 2012 International Building Code (IBC) No State amendments included in

discussion

This discussion is conceptual and general by nature. Time allotted does not allow for in-depth analysis of salient points – READ, READ, READ.

Disclaimer

This discussion does not pretend to include all items the code user needs to be aware of. Frequent, careful reading of the code is essential to understand its many intricacies.

The handout does not take the place of owning or reading the code.

Important Definitions

Means of egress: A continuous and unobstructed path of vertical and horizontal egress travel from any occupied portion of a building or structure to a public way. A means of egress consists of three separate and distinct parts: the exit access; the exit; and the exit discharge.


Exit Access: That portion of a means of egress system that leads from any occupied portion of a building or structure to an exit.

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Exit: That portion of a means of egress system between the exit access and the exit discharge or public way. Exit components include exterior doors at the level of exit discharge, interior exit stairways, interior exit ramps, exit passageways, exterior exit stairways, exterior exit ramps and horizontal exits.


Exit Discharge: That portion of a means of egress system between termination of an exit and a public way.

Public Way: A street, alley or other parcel of land open to the outside air leading to a street, that has been deeded, dedicated or otherwise permanently appropriated to the public for public use and which has a clear width and height of not less than 10 feet.

Egress Components Existing Buildings (1001)

It is illegal to alter or reduce means of egress (number or capacity) in an existing building below that which is required by the code.

Means of egress must be maintained per the IFC

Chapter Layout

1003 – 1013: apply to all three elements

1014 – 1019: additional exit access req.

1020 – 1026: additional exit req.

1027: additional exit discharge req.

1028: assembly MOE req.

1029: emergency escape/rescue req.

Protruding objects

Cannot be less than 80” AFF (78” for door closers and stops)

Anything lower requires cane barrier – look out for areas under stairs at lowest level; and for area under drinking fountains, fire extinguishers, telephones, light fixtures, etc. that are free-standing or that protrude more than 4” from wall.

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Occupant Load: 1004

1004.1.2, no fixed seats: Use Table 1004.1.2 to calculate # occupants by area – look out for gross or net

Note: the 2012 IBC allows exception for local BO to accept actual occupants even if lower than calculated

Can increase above Table – 1 per 7 s.f.

Occupant Load: 1004

1004.4, Fixed seats: count the number of seats; if not divided count 18” of seat length per person.

1004.3 requires posting of occupant load – this cannot be used to figure lower # of occupants than T. 1004.3

1004.1.1.1, Cumulative loads: where path of egress travel has intervening rooms or adjacent levels you must add those people

Outdoor areas: 1004.5

Usable outdoor spaces such as yards, patios and courts shall have MOE according to use (occupant load set by BO). Need not add to building’s total occupant load if not used by persons in addition to building’s occupant load (non-simultaneous occupancy)

Sizing of Components: 1005

Stairs: 0.3 inches per occupant (0.2” in sprinklered building other than H & I-2 with emergency voice alarm)

Other components (doors, ramps, corridors, etc.): 0.2 inches per occupant (0.15” in sprinklered building other than H & I-2 with emergency voice alarm)

Sizing of Components: 1005

Door capacity based on net clear width

# occ. X factor = req’d. clear width

Clear width ÷ factor = capacity

Egress Convergence: 1005.6

When exits from upper and lower levels (ie: second floor and basement) converge at an intermediate level (ie: first floor) the capacity of the MOE at that point must be sized for the two adjacent stories.

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Egress Convergence: 1005.6 Emergency Illumination: 1006

Required for 90 minutes in rooms or spaces required to have two or more means of egress and in the corridors, exit enclosures and exit discharge serving those spaces

See 1006.3 for detailed requirements

Accessible MOE: 1007

Required in new construction. Not in alterations or change of occupancy by model code.

If one exit, it must be accessible; if 2 or more exits, 2 must be accessible

1 MOE from accessible mezzanines must be accessible


Acceptable components: accessible routes; compliant interior and exterior stairs; specially equipped elevators and platform lifts; horizontal exits; ramps; areas of refuge; and exterior areas for assisted rescue.

Elevators required in buildings with accessible floors 4 or more stories above LED

Exceptions in sprinklered buildings for floors with horizontal exit or floors served by ramps


Stairs & Areas of Refuge: not required in sprinklered buildings (13 or 13R)

Platform lift: allowed as accessible MOE where allowed as accessible route

Standby power required

Cannot be in enclosed hoistway


Exterior area for assisted rescue

Required where exit discharge not accessible

No exception for sprinklered buildings

See 1007 for separation, communication & signage requirements

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Exterior area for assisted rescue Doors: 1008

Minimum 32” clear (one leaf in pairs). Maximum 48” nominal.

See 1008.1.1 for exceptions

Egress doors must swing (see 1008.1.2 for exceptions)

In direction of egress travel where serving 50 or more or Group H (deleted “serving exit enclosure” )

Doors: 1008

Special rules for revolving doors; power-operated doors; horizontal sliding doors & security grilles.

Doors in series require 48” clear plus width of door – must swing in same direction or away from each other

Must be readily openable from egress side unless specifically allowed by code

Doors: 1008

Panic and fire exit hardware: required on Group H doors; Group A or E doors serving room or space with 50 or more occ.; and electrical rooms w/equip rated 1,200 amps or more and over 6’wide

Gates follow same rules as doors – see 1008.2 for exceptions.

Turnstiles – max. 50 person egress cap. Per turnstile

Stairways: 1009

Exit stairs shall be enclosed per 1022

Exit access stairs need not be enclosed.

Generally are located in same story; in DU; between story and mezzanine; serving balconies, stages & press boxes; or in atrium or “hole in floor” (convenience)

Min. width = 44” (36” if less than 50)

Exc. for spiral; aisles; stair lifts in DU’s

Stairways: 1009

Headroom = 80” measured in line connecting edge of nosings (draw it)

Dimensional uniformity most important! Look for it in alterations and when adding or deleting floor coverings.

Exterior stairs cannot accumulate water (in any form, including frozen)

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Stairways: 1009

Enclosures under stairways:

Interior – enclosed usable space under stairs must be rated to match enclosure (1 hour for unenclosed stairs) – no access to enclosed space from stair enclosure

Exterior - enclosed usable space under stairs must be 1 hour rated. Open space under exterior stair shall not be used for any purpose.

Stairways: 1009

See special requirements for curved stairs (1009.11), spiral stairs (1009.12), alternating tread devices (1009.13), and ship ladders (1009.14 – permitted in I-3 only)

Handrails – required both sides of all stairs (see exceptions for aisle stairs, DU’s and single steps in decks, patios, walkways). New section for handrails – 1012.

Stairways: 1009

New 2012: 1009.16.2 – roof hatch openings within 10 feet of roof edge require guards.

New 2012: 1009.17 – roofs and penthouses containing elevator equipment requiring service required to have stairway.

Ramps: 1010

If it slopes 1:20 (5%) or less it is a sloped walkway – no special requirements.

If it slopes between 1:20 and 1:12 (code says 8%, but it’s really 8.3%), it’s an accessible ramp and requires landings, handrails, edge protection, guards where applicable, etc.)

Ramps: 1010

Pedestrian ramps not required to be accessible may slope as steeply as 1:8 (12.5 %); but no ramp can ever exceed that slope if used by people.

Exit Signs: 1011

Required when more than one MOE:

In rooms or spaces that require more than one means of egress

In exit access corridors & exit passageways (no point more than 100’ or listed viewing distance, whichever less, from sign)

At exit and exit access doors

See exceptions at 1011.1

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Exit Signs: 1011

1011.2 requires floor level exit signs in R-1

1011.4 requires raised character and Braille exit signs at all exit doors

Handrails: 1012 General requirements (but see exceptions):

Required both sides

Must be continuous (look for brackets)

Must be graspable (Type I or Type II)

Extensions required at top and bottom – both sides (look for on plan review - hard to retrofit)

Max. projection = 4 ½” both sides (ramp min. clear width = 36”)

Guards: 1013

Required when the difference between a walking surface and the surface below is 30” or more measured at any point within 36” of edge of walking surface

See 1013.2 for exceptions

Min. height = 42” from walking surface, ramp surface or line connecting stair nosings (see 1013.3 for exceptions)

Guards: 1013

Opening limitations (based on sphere):

0” to 36” = 4”; 36” to 42” = 4 3/8”

6” at triangle formed by riser, tread, rail

21” at I-3, F, H or S; or raised surfaces for mechanical equipment access

4 3/8” within R-2 and R-3 DU’s and SU’s

Assembly at fascia at end of aisles: 0” to 26” = 4”; 26” to 42” = 8”

Guards: 1013

1013.5: guards required at screened porches over 30” above grade

1013.6 & 1013.7: guards required at mech. equip. & roof access within 10’ of roof edge when over 30” above grade

1013.8: NEW 2012 – provides window fall protection devices for R-2 and R-3 dwellings

Exit Access: 1014 Path through intervening spaces (general):

Must be accessory to one another

Cannot be Group H

Must provide discernible path of travel

Cannot be locked

From DU’s cannot be through other sleeping area, toilet or bathroom

Cannot be kitchen or storage room

Cannot be other tenant

See 1014.2 for exceptions

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Common Path of Travel: 1014.3

The exit access distance one can travel until you have a choice of paths to two different exits.

Exit/Exit Access Doorways:1015

This section regulates number of doors from a room or space within a building; not from a building or a floor within a building (that’s 1021).

Two doors req’d. when common path of travel exceeds 1014.3; when # of occ. exceeds T.1015.1 (see excep.); in certain mech. equip spaces; and …….


New in 2012: spaces used for daycare for more than 10 children 2 ½ or less require two doors


When two doors are required, they must be remote from one another; when three doors are required, two of them must be remote:

½ the maximum diagonal of the room or space where not sprinklered

1/3 the maximum diagonal of the room or space when sprinklered


Distance between doors is measured in a straight line (center of door to center of door)

Exception: when two exit stairs are connected by a one-hour rated corridor, the separation distance is measured as the shortest line of travel within the corridor

Exit Access Travel Distance: 1016

This is the distance, given in T. 1016.2, that one must travel from the most remote part of a building to one (the closest) exit. It must be measured along the natural and unobstructed path of horizontal and vertical travel. If it involves exit access stairs or ramps, measure along the slope of the stair or ramp.

Measure TD at right angles to allow for furniture within rooms or spaces

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Exit Access Travel Distance: 1016 Corridors: 1018

Things to check for:

Is a rating required? Different for sprinklered/not sprinklered.

Minimum width? Based on number of occupants and occupancy – also check capacity (see 1005)

Dead ends – general rule 20’ but lots of exceptions.

Air movement within corridor and above ceiling.

Continuity – rated corridors must be continuous without intervening rooms.

Number of exits: 1021

This section regulates number of exits each story and an occupied roof in a building must have (two unless otherwise stated in code)

Where multiple exits are required, all occupants of story must have access to all exits

New for 2012 – regulates number of exits from each story within a building. 2003 IBC regulated entire building as a whole.



501 to 1000 occupants in a story requires three exits

Over 1000 occupants in a story requires four exits

New: Additional exits required for buildings over 420 feet in height (see 403.5.2)

Multiple exits must be remote per 1015 and must be continuous to exit discharge

Interior exit stairs & ramps: 1022

Enclosure rating (fire barriers or horizontal assemblies or both):

Two hours when connecting four or more stories (including basements)

One hour when connecting three or fewer stories (including basements)

Must terminate at exit discharge or public way

May be extended by exit passageway

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Interior exit stairs & ramps: 1022 Things to look out for:

Openings

Penetrations (new for 2012 – protected membrane penetrations permitted)

Exterior wall protection

Discharge identification – barrier at LED

Stairway identification signs (more than 3 stories)

Smokeproof/pressurized stairs (high rise & underground buildings)

Exit Passageways: 1023

Shall only be used for MOE

Width: 0.2”/occ.; 44” min.; 36” ‹ 50

Rating: same as stair/ramp extending

Termination: at LED: @ exit discharge; other levels: @ exit

Openings & penetrations: same as exit enclosures

Luminous Egress Path Markings: 1024

Only required in High Rise exit enclosures per 2012 IBC Model Code

Horizontal Exits: 1025

Shall not be only exit from area – where 2 or more exits req’d; not more than ½ in number and width shall be horizontal exits (but see exception to 1025.4)

2/3 in I-2

100% in I-3 (6 s.f. per occ. AOR for total number in adjoining compartments)


Separation: min. 2 hour fire wall;

Or 2 hour fire barrier, horizontal assembly or both

Must extend vertically throughout building

Continuous from exterior wall to exterior wall


Area of refuge:

Must be public area or same tenant

Accommodate original occupant load of refuge area plus capacity of exit doors in horizontal exit

3 s.f/occ; 6 s.f./occ I-3; 15 s.f./occ ambulatory I-2; 30 s.f./occ non-ambulatory I-2

Not same as accessibility AOR

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Exterior Exit Stairs & Ramps: 1026

Cannot be used for I-2 or high-rise

Other occ. 6 stories or less

Look for:

Open on at least one side

Min. 10’ from lot lines & other buildings

Separation from building interior (1026.6)

Exit Discharge: 1027

Exits are required to discharge directly to the exterior, at grade or with direct access to grade

50% may discharge through LED with conditions

50% may discharge through compliant vestibule

May not take both exceptions

Exit Discharge: 1027

Exit discharge shall provide access to public way

Exception for safe dispersal area:

5 s.f. per person

On same lot 50’ from building

Permanently maintained and identified

Safe, unobstructed path of travel from building

Assembly MOE: 1028

Things to look for:

Main entrance/main exit: ½ when over 300

Other exits: ½

2 MOE from balconies, galleries with more than 50

Aisle width: different for smoke protected and not smoke protected

Travel distance/common path of travel

Assembly MOE: 1028

Aisle accessway width (space between seats in rows)

Aisle walking surface: sloped or risers

Seat stability

Handrails

Guards

Emergency Escape & Rescue: 1029

Required in R-2 & R-3: basements & sleeping rooms below 4th floor

Min. size: 5.7 s.f.; 24” high; 20” wide

5.0 s.f. @ grade floor

44” fin. fl. to opening

Operate without key or tool

Window wells required at basements

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The End

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