1 June 1998
STRUCTURAL CONSIDERATIONS FOR METAL ROOFING
1. PURPOSE AND SCOPE. This document prescribes the criteria and procedures for
designing metal roofs for buildings.
2. APPLICABILITY. These instructions are applicable to all USACE elements responsible for
designing military construction projects.
(1995) American Society of Civil Engineers-Minimum Design
Loads for Buildings and Other Structures
AISI Specification for the Design of Cold-formed Steel Structural
Aluminum Construction Manual Series, Section 1 Specifications
for Aluminum Structures
ASTM E I592
Standard Test Method for Structural Performance of Sheet Metal
Roof and Siding Systems by Uniform Static Air Pressure
National Roof Contractors Association Manual
Sheet Metal and Air-Conditioning Contractors National
4. METAL ROOF TYPES.
a. General. Metal roofing consists of cold-formed, corrugated, fluted, or ribbed metal sheets
attached to the exterior of a building to serve as the exterior covering of the structure. Metal
roofing may be either structural or nonstructural. The structural metal roof is designed so the
roofing panels support all out-of-plane applied loads. Forces in the plane of the roof, diaphragm
loads, are typically resisted by supplemental decks or X-bracing. The nonstructural roof depends
upon a substrate to carry the applied loads. Metal roof types may be further subdivided into
types with lapped side seams and exposed fasteners, types with standing side seams and
hidden metal clip fasteners, and hybrid types, such as those with snap seams or battens that fall
somewhere in between. There are many types of metal roofing produced by the metal
manufacturing industry and care must be exercised during design to ensure that the type
specified is compatible with the main structural framing system or substrate.
(1) Detailing. Generic details of valley, expansion joints, flashing, underlayments, roof
penetrations, curbs for mechanical equipment, eaves, ridges, intersections, and other unique
situations of the roof system must be provided, along with necessary supporting framing, to
assure viable roof performance. Excessive details to avoid are roof panel configurations and