No, they are not the same, but they are both related to the construction of tornado shelters. FEMA 361“Design and Construction Guidance for Community Safe Rooms” is a guidance document, but FEMA does not regulate building construction. ICC 500 “Standard for the Design and Construction of Storm Shelters” is written by the International Code Council® and is referenced in the International Building Code in all Editions since 2009.
Many SDI manufacturers have single swing doors that are 4’0” x 8’0″, and pairs that are 8’0″ x 8’0″, listed with the Florida Building Commission. Special sizes are also permitted by the code to be analyzed by a Registered Design Professional if they fall outside of existing approvals.
As a general rule, the closer a building is located to the coastline, the higher wind speeds it is expected to experience. The wind speed and debris impact zones for Florida are defined by a map that is found within the Florida Building Code.
Hurricane resistance ratings are expressed in pounds-per-square-foot (PSF) values, and unlike fire ratings, there are no standard increments. In addition to the PSF values, they are either listed with or without “missile” impact ratings. In this instance, a missile refers to a 2 x 4 piece of lumber weighing 9 lbs. that is fired at the door at 35 miles-per-hour. A door assembly must withstand 3 impacts in order to have a missile impact listing. A typical door listing would be expressed as;
- Design Pressure Rating +75/-65 PSF
- Large Missile Impact – Yes
This listing indicates that the door assembly is rated for 75 PSF when loaded against the stops of the frame, and 65 PSF when loaded away from the stops of the frame
Some manufacturers have options for aesthetic finishes on these doors, but due to the severity of the testing requirements, almost all tornado shelter doors are very heavy-duty steel designs.
Yes, SDI members offer door assemblies certified to FEMA 361. These openings must be tested and installed as a system including the hinge, door, frame, anchors and latching hardware. The architect or specifier should investigate the doors available that would satisfy the requirements for those openings.
Openings, specifically hardware, have been tested to comply with FEMA 320 and 361 that have the bottom bolt engaging into the hardware rabbet of the frame. This eliminates the bottom rod engaging into the floor and can be single acting function that would comply with ADA requirements.