In this month’s featured article, we will walk you through some of the significant changes related to fire and smoke protection in the new International Building Code, 2009 Edition (IBC 2009).
We hope this article will provide you a quick overview of how some of these changes can affect the design, construction, inspection and maintenance of your buildings.
Clicking on the section hyperlinks within the article will provide you temporary online access to the new IBC 2009 at MADCAD.com. Temporary access will expire on 7/23/2009.
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Photo: Courtesy of Letra-Tek
IBC 2009 requires the marking and identification of fire and smoke barriers to ensure penetrations are protected. |
MARKING AND IDENTIFICATION OF FIRE BARRIERS
IBC 2009 added a new section that requires the permanent marking and identification of fire walls, fire barriers, fire partitions, smoke barriers and smoke partitions or any other wall required to have protected openings or penetrations (a requirement that used to be part of SBCCI’s Standard Building Code).
The new section
703.6 provides specific set of requirements on the location, size and wording of these markings.
SPRAYED FIRE-RESISTANT MATERIALS
IBC 2009 added new requirements for the installation of sprayed fire-resistant materials (SFRM) applied to structural members.
The new section
704.13 addresses the fire resistance rating, surface condition, temperature and finished condition requirements for SFRMs.
IBC 2009 also revised SFRM special inspection requirements in section
1704.12 and minimum bond strength requirements for high-rise buildings in section
403.2.4.
EXTERIOR WALL PROJECTIONS
For exterior wall projections such as eave overhangs or balconies, IBC 2006 required the maximum projection distance to be the lesser one of the following two methods:
• Point one-third the distance to the lot line from an assumed vertical plane located where protected openings are required; and
• 12 inches into areas where openings are prohibited.
IBC 2009 revised section
705.2 for the first method, requiring the distance to be measured from the exterior face of the wall in lieu of the assumed vertical plane of the opening.
IBC 2009 also added a third method to determine the maximum projection distance (the lesser distance of the three must be used). According to the revised section
705.2, the third method is:
• Point one-half the distance from the exterior face of the wall to the lot line where all openings in the exterior wall are permitted to be unprotected or the building is equipped throughout with an automatic sprinkler system.
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Photo: Kim Takar
IBC 2009 revised the fire-resistance rating requirement for exterior walls. |
EXTERIOR WALL FIRE RESISTANCE RATINGS
The requirement that determines the side of the exterior wall to receive rating for exposure to fire is revised in IBC 2009.
According to the revised section
705.5, an exterior wall, which is required to be fire-resistance rated, must be rated for exposure to fire from the inside if the fire separation distance is greater then 10 feet (the distance was 'greater than 5 feet' in IBC 2006).
If the fire separation distance is less than or equal to 10 feet, then the fire-resistance rated exterior wall is required to be rated for exposure to fire from both sides.
EXTERIOR WALL ALLOWABLE AREA OF OPENING
IBC 2009 revised Table
705.8 that specifies the maximum area of exterior wall openings based on fire separation distance and degree of opening protection.
Although the opening percentage values in the table have not changed from IBC 2006, the fire separation distance ranges which determine what category the exterior wall falls into -for the permitted opening percentage- have changed.
For example, the fire separation distance wording is revised from 'greater than 5 to 10 (feet)' to '5 to less than 10 (feet)', which means that a fire separation distance of 5 feet now falls into a different opening percentage category.
FIRE WALL OPENINGS
IBC 2009 revised section
706.8, and increased the maximum opening area in a fire wall from 120 square feet (in IBC 2006) to 156 square feet.
The requirement that limits the aggregate width of openings at any floor level to maximum 25% of the length of the wall has not changed.
Additionally, each opening is still required to be protected in accordance with section
715.4 which specifies the rating requirements for fire doors and shutter assemblies.
ELEVATOR LOBBY
IBC 2006 required an enclosed elevator lobby at each floor where an elevator shaft enclosure connects more than three stories.
One of the exceptions to this requirement was if the building was protected by an automatic sprinkler system, enclosed elevator lobbies were not required. However, Group I-3 occupancies and high-rise buildings were not permitted to be exempt from this requirement even if they were sprinklered.
IBC 2009 revised section
708.14.1, and added Group I-2 occupancies to the list of occupancies and building types listed above that are exempt from the sprinkler exception.
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Photo: Denis Raev
IBC 2009 revised the pressurization requirements for elevator hoistways. Elevator hoistway pressurization can be used as an alternative to enclosed elevator lobbies. |
ELEVATOR HOISTWAY PRESSURIZATION REQUIREMENTS
IBC 2009 increased the positive pressure requirements of elevator hoistways where pressurization is provided in lieu of enclosed elevator lobbies.
According to section
708.14.2.1, a minimum positive pressure of 0.10 inches of water (0.04 in IBC 2006) and a maximum positive pressure of 0.25 inches of water (0.06 in IBC 2006) is required to be maintained in pressurized elevator hoistways.
SMOKE BARRIER OPENINGS
IBC 2006 provided a specific set of requirements for doors installed across corridors in Group I-2 occupancies. According to these requirements, undercuts were not permitted in these doors.
IBC 2009 revised section
710.5 which now permits doors installed across corridors in Group I-2 occupancies to have undercuts up to 3/4 inches.
EXTERIOR CURTAIN WALLS
IBC 2006 required the voids created at the intersection of exterior curtain walls and fire-resistance rated floor/ceiling assemblies to be sealed by an approved system to prevent the interior spread of fire.
IBC 2009 added a new section to address the voids created at the intersection of exterior curtain walls and non-rated floor/ceiling assemblies. According to the new section
714.4.1, the void is required to be sealed with an approved material or system to retard the interior spread of fire and hot gases between stories.
