Navigating Changes to Tornado Shelter CodesNovember 27th, 2017 | Category: Industry News
The 2015 International Building Code (IBC) mandates the construction of tornado shelters for occupants of new K-12 schools, critical emergency operations centers, and fire and police stations within the 250-miles-per-hour wind zone in the U.S. The adoption of the ICC 500-2014, ICC/NSSA Standard for the Design and Construction of Storm Shelters (ICC 500-2014) will change a building’s door and window impact testing.
In a recent webinar, ASSA ABLOY representatives spoke about the changes in tornado shelter requirements and how they will affect design professionals, project managers and code officials.
According to Kurt Roeper, director of industry affairs for codes and standards, a tornado hit a high school in Enterprise, Ala., in 2017, killing nine people. The disaster was the catalyst for legislation in Alabama mandating the requirement that all schools have shelters compliant with ICC 500-2014.
Mandatory requirements for shelter construction were first introduced in 2015. ICC 500-2014 is now the reference standard of the 2015 IBC. It requires that schools housing more than 50 students have shelters to accommodate all occupants, including students, teachers and administrators.
ICC 500-2014 requires that: “Anchorage of door, window or shutter framing to the shelter structure is required by means other than those provided in the manufacturer’s listing or installation instructions in accordance with Section 107, alternate anchorage shall be designed for pull-out and shear, and the anchor placement detailed in accordance with accepted engineering practice.
The alternate anchorage details and calculations shall be provided as part of the construction documents. ICC 500-2008 did not discuss anchorage requirements or require that any additional information on the design of anchors be provided. These requirements will help ensure that a proper load path is provided for doors, windows, and shutters.”
Another change from the 2008 code requires that tests be conducted on the maximum and minimum sized doors and windows used in the building.
The 2018 International Existing Building Code will trigger the application of the requirements to additions to existing facilities.
“All or part of 22 states are within the 250-miles-per-hour wind zone. The requirements will be mandatory when states adopt the 2015 code. Right now we’re still on the front end of the adoption curve,” says Roeper.
Design trends created by early adopters of the code include large spaces, small spaces and a hybrid of the two approaches.
Many K-12 schools are using large spaces such as gymnasiums as shelters because of the occupancy advantage. The distance students have to travel to reach the shelter could be a concern in larger schools. Thus, this approach is most often used for older students because they know how to get to a shelter within the allotted time. Smaller spaces, such as classrooms as individual shelters, are used for younger children and special needs students to prevent them from needing to relocate.
The small space method is also useful for additions to existing buildings while the hybrid method takes both situations into considerations.
According to Roeper, education construction is forecasted to peak at $63.8 billion in 2019 and will remain at least a $40-billion segment.
According to Chris Hill, product manager of exit devices at ASSA ABLOY, three types of hardware solutions can be used to meet ICC 500-2014 requirements: multi-point locks, shutters and exit devices.
ICC 500-2014-compliant shutters can be attached to windows to protect students. They remain open during everyday use to provide daylighting and views, but close during a tornado event to protect the building occupants.
Schools, police stations and fire stations all have different everyday requirements that designers must take into account.
“Schools need locks that can stand up to high use and are easy to operate so that children can get through without issue. Police stations prioritize security as their highest concern. They also require access control and protection. Only authorized individuals have access to specified areas in the facility. Fire fighters need to move fast while managing heavy equipment,” says Hill.