All Things Gypsum
The Premier Publication: GA-600
Great care is taken to ensure that the content of the FRDM is correct and current when a new edition is created. The updating process is methodical and involves a minimum of two full member company reviews of the entire (both existing and proposed) text. From the time the updating process is initiated until the day that the initial copies are distributed to the public, it commonly takes 18 months to produce a new edition of the FRDM.
The written wordThe FRDM has been published in a format approximating the current since the early 1960s. Prior to that time, the Association published The Fire Resistance of Gypsum Plaster (1938), a simple document that contained text-only descriptions of a handful of fire-resistive systems constructed using gypsum plaster over a variety of substrates such as wood and metal lath, clay tile, concrete, masonry, and gypsum plaster board. The 1938 document evolved sometime in the early 1950s into the Fire Resistance Manual: Gypsum Lath and Plaster, a 1958 copy of which appears to be the first predecessor to the modern FRDM that contained pictorial diagrams of fire-resistive systems. Like its 1938 forerunner, the 1950s Fire Resistance Manual concentrated on the fire-resistive installation of gypsum plaster and mentioned gypsum board materials only when it discussed gypsum lath. Interestingly, the 1958 manual contained an illustration that demonstrates how gypsum retards heat transmission; this same illustration, updated to contemporary graphic standards, is still used in the FRDM and appears as Figure 2 on page 13 in the 2003 edition.
Gypsum wallboard first appeared as a focal point for fire-resistive systems in a 1961 publication titled the Fire Resistance Design Manual. This document is considered to be the first edition of the contemporary FRDM. It is also the first iteration of any of the documents that delineated systems by fire-resistance rating (one hour vs. two hour and so forth) as well as by construction type. In 1964 the document name was modified to Fire Resistance Design Data. It would retain this title until 1975 when it permanently reverted back to Fire Resistance Design Manual.
The FRDM evolved during the 1960s and 1970s to reflect the movement in construction methods away from plaster systems and toward gypsum board. Early 1960s versions show a strong partiality toward plaster; easily 80 percent or more of the systems in the 1964 edition are plaster-covered designs. By 1971, however, the opposite is true and the balance of listed systems had tilted almost entirely toward those incorporating gypsum board. Sound test data also appeared for the first time in 1966, when listed systems displayed accompanying Sound Transmission Class test results.
The majority of the changes to the FRDM since the 1970s reflect a substantial increase in the volume of incorporated supplemental information—“The General Explanatory Notes” section, for example, has been expanded from one partial column in 1978 to two pages in 2003—and format modifications necessitated by technological changes in the production and printing of documents. The number of systems in the FRDM has increased by more than 50 percent since 1983 and the entire FRDM page count has more than doubled during the same time. The document revision cycle has also been standardized since that time. During the 1970s and 1980s, the manual was revised on an irregular schedule. For the past 10 years, it has been revised and reprinted using a planned three-year cycle. Standardizing the revision process timetable helps Association member companies strategize their use and purchase of the document and facilitates staff data accumulation and printing tasks.
A review of the Preface to the 1961 edition indicates that the concept of the FRDM has remained the same for more than four decades: “The purpose of this Manual is to provide the designer with data on a wide selection of related construction assemblies—rather than materials—so that he may see at a glance their relative performance characteristics.” While the first paragraph of the Introduction section to the 2003 FRDM is a bit more encompassing—it also acknowledges code officials, fire services, and the insurance industry, for example—it carries the same message as its predecessor documents: the manual is to be used to “[compare] characteristics [allowing] the user to be more accurate in meeting design and
Filed by typeEach system in the FRDM is categorized first by construction type and then by fire rating and sound test classification. Comparable systems are arranged in close proximity within the FRDM to facilitate evaluation. Individual systems are portrayed using a format that presents relevant numerical fire rating and sound rating (if applicable) information, a textual system description, and a pictorial system representation. This basic layout has been in place for more than three decades.
Individual systems are assigned a GA file number. These GA file numbers are used solely for categorization purposes and have no numerical relationship to the system fire or sound information, substantiating test reports, or information about materials used in the system.
Systems proposed for incorporation in the FRDM come from three different sources. Most are presented to the association by a member company of the association and are independent tests that have been sponsored by or conducted by the member company. These systems often reflect the use of proprietary gypsum board materials and tend to be the most “cutting edge” systems incorporated into the document. Tests sponsored by the Association are another source of systems for the FRDM. Association-sponsored tests always produce generic systems. The two-hour floor- and roof-ceiling systems based on Underwriters Laboratories Design L 556 that are incorporated in the 2003 edition of the FRDM are examples of a fire test that was sponsored by the Association.
Tests conducted by organizations that have a close working arrangement with the association are the third source of system information for the FRDM. These tests are typically sponsored by another industry organization, usually with the financial or engineering support of the association, and always reflect the use of generic gypsum board materials. Regardless of the source, all of the proposed test reports are scrutinized thoroughly by the staff and the members of the Gypsum Association Technical Committee prior to incorporation into the FRDM. Each proposed system must comply with the written standards set for the Manual and a complete set of test data must be presented prior to consideration of a specific system.
The FRDM has gained wide acceptance and has been widely distributed since its inception. In model building code documents, for example, it is referenced as an acceptable source of information by the Standard Building Code, the Uniform Building Code, the International Building Code, and the NFPA 5000 Building Construction and Safety Code. It is referenced in the code documents of major jurisdictions in the United States such as South Florida, Chicago, Los Angeles, and New York City. Systems contained in the FRDM are reproduced liberally within architectural construction documents (the association allows designers to freely transpose individual system information into construction documents) and its use as a reference text has been documented in numerous fire design textbooks and building code commentaries. Based on current distribution levels, it is likely that more than one-half of a million copies of the FRDM have been distributed since 1961.
The current edition of the FRDM was published in April 2003 and is the 17th edition of the modern document. It contains more than 325 individual systems including new two-hour floor- and roof-ceiling systems and fully loaded partition systems. Almost 50 systems appear in the FRDM for the first time.
The FRDM is probably best described as a living document—a compendium of information presented in a useful format that is intended to evolve over time. Given the perpetually changing face of gypsum board products, it is intended that the document should grow and expand to incorporate new technologies and products as they become available. The FRDM is a valuable tool for every construction professional and should be an essential part of a company reference library. Copies are available at a nominal cost from the Gypsum Association.