The metal manuals

Professional Roofing has discussed NRCA's roofing manuals at length, but we have not explored how NRCA's manuals are used in the field compared with manuals of other trade organizations. In this article, we'll explore how NRCA's Architectural Sheet Metal and Metal Roofing Manual compares with the Metal Building Manufacturers Association's (MBMA's) Metal Roofing Systems Design Manual.

An overview

NRCA's and MBMA's manuals strive to achieve the same goal: Help roofing industry professionals design and install long-lasting metal roof systems. A look at each manual's table of contents reveals some differences in the way the organizations approach their audiences.

For example, NRCA specifically addresses architectural sheet metal, architectural metal panels and structural metal panels in separate sections. Then, the manual includes a moisture-control section, glossary and construction details. All NRCA members receive the manual as a member benefit. NRCA estimates about 8,500 roofing professionals have the manual.

MBMA, on the other hand, divides its manual by topic rather than roof system type. Its sections include system components, substrates, specifications and standards, retrofit applications, common industry practices, design practices, installation and maintenance, energy, fire protection, supplemental information, quality certification and details. All MBMA members receive its manual, as well. About 1,500 roofing professionals have the MBMA manual.

But how were the manuals meant to be used, and how do roofing professionals use them?

NRCA's manual

Jude Laperouse, president of Edward J. Laperouse Metal Works Inc., Houma, La., served on the NRCA technical committee that helped revise the Architectural Sheet Metal and Metal Roofing Manual.

According to Laperouse, "The goal of NRCA's committee work was to use our real-world experience to produce drawings and details that yield long-term performance."

Laperouse explains NRCA's details—by design—address roof systems that require a high degree of craftsmanship and attention to moisture protection.

Allen Lancaster, president of Metalcrafts Inc., Savannah, Ga., uses NRCA's manual fairly frequently.

"We use NRCA's manual for shop drawings, submittals and as a guide for roof system installation," he says. "The manual has a wealth of information and details for sheet-metal flashings."

Lancaster continues: "The joinery section provides easy-to-use details. It also includes lap joints, cover plates, concealed plates, etc., for applicable flashing details. Isometric and section views are provided."

MBMA's manual

MBMA's manual contains information useful to designers and contractors. Lee Shoemaker, MBMA's director of research and engineering, says contractors will find information in the Common Industry Practices section useful; the section discusses the responsibilities of all parties involved with a metal roof system, delivery and receipt issues, installation and other field work. In addition, the Supplemental Information section includes information about fastener types and applications.

"MBMA's objective was to put out a comprehensive manual for metal roof systems with a particular focus on good detailing practices," Shoemaker explains. "The manual contains 86 details addressing the most commonly encountered situations with trapezoidal and vertical rib metal panels. AutoCAD files are included on the CD-ROM that accompanies the manual so the details can be incorporated into project documents."

"Although we have not used MBMA's manual for submittals, we have used it as a reference manual," Lancaster says. "There is good information about metal purlin design, specification guidelines, basic metal retrofit design and structural design, as well as many details of structural standing-seam metal roof flashings for trapezoidal and vertical rib design."

MBMA wants its manual to be seen as a complement to NRCA's manual, not competition.

"MBMA never has felt competition with NRCA with regard to a metal roofing manual," Shoemaker says. "We believe the manuals complement one another. MBMA hopes to work more closely with NRCA in the future to make sure we don't have conflicting information and, perhaps, other industry groups to publish a comprehensive manual that combines all industry knowledge into one document."

Other manuals

Shoemaker points out there are other industry organizations that publish manuals. All manuals offer specialized information to roofing professionals—and roofing professionals ultimately choose the manuals that address their particular lines of work.

For more information about NRCA's manual, click here. Additional information about MBMA's manual can be found on www.mbma.com.

Ambika Puniani Bailey is editor of Professional Roofing and NRCA's director of communications.