What is a standing seam metal roof?

What is a standing seam metal roof made of?

Standing seam panels are formed from metal sheet, most often steel, aluminum or copper, and the metal has to resist rust on its own or through a coating such as zinc or aluminum-zinc. The Department of Energy guide and Seattle's residential code say: “The most common materials for metal roofing are steel, aluminum, and copper.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30. “These materials are either naturally corrosion-resistant or made corrosion-resistant when manufactured in accordance with building code-referenced standards.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30. In Seattle, Washington, “The materials used for metal-sheet roof coverings shall be naturally corrosion resistant or provided with corrosion resistance in accordance with the standards and minimum thicknesses shown in Table R905.10.3(2).” Source: City of Seattle, Department of Construction and Inspections, read 2026-10-30.

How do the Department of Energy and the federal roofing specification describe a standing seam metal roof?

A standing seam metal roof is one of the two kinds of metal panel roof: its seams stand up above the flat of the panel, run straight down the slope, and hide the fasteners. The Department of Energy guide and the federal Unified Facilities Guide Specification 07 61 14 describe it: “There are two general types of metal panels: “exposed fastener” panels and “standing seam” panels.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30. “Standing seam panels, also known as vertical seam panels, are site made, attached to the roof with concealed fasteners, and highly resistant to wind and wind-driven rain.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30. “Apply roofing panels with the standing seams parallel to the slope of the roof.” Source: U.S. Army Corps of Engineers, NAVFAC and AFCEC (Unified Facilities Guide Specifications, on WBDG), read 2026-10-30.

How long does a standing seam metal roof last?

The Department of Energy guide says a metal roof can last up to 50 years or more, a figure for metal roofs in general rather than standing seam alone, and the federal specification for military buildings asks for a manufacturer warranty of at least 20 years. They say: “Metal roofing tends to cost more than asphalt shingles, but a metal roof can last up to 50 years or more.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30. “Metal roofs are durable, low maintenance, and can be repainted.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30. “Specify a minimum 20-year warranty unless directed otherwise by the Government.” Source: U.S. Army Corps of Engineers, NAVFAC and AFCEC (Unified Facilities Guide Specifications, on WBDG), read 2026-10-30.

What is the minimum slope for a standing seam metal roof?

Seattle's residential code, which follows the International Residential Code here, lets a standing seam roof go as low as 1/4 inch of rise per 12 inches of run, a 2% slope, while lapped metal panels without sealant need 3 in 12. The code and the federal specification say: In Seattle, Washington, “The minimum slope for standing-seam roof systems shall be 1/4 unit vertical in 12 units horizontal (2-percent slope).” Source: City of Seattle, Department of Construction and Inspections, read 2026-10-30. In Seattle, Washington, “The minimum slope for lapped, nonsoldered-seam metal roofs without applied lap sealant shall be 3 units vertical in 12 units horizontal (25-percent slope).” Source: City of Seattle, Department of Construction and Inspections, read 2026-10-30. “This guide specification is primarily for Steel Structural Standing Seam Metal Roofing Systems (SSMRS), such as Self-Supporting Systems designed to span from purlin to purlin at slopes as low as 2 in 24 1 inch per foot versus architectural (non-structural) cladding systems that require continuous support, secondary moisture protection and slopes no less than 1 in 4 3 inches per foot.” Source: U.S. Army Corps of Engineers, NAVFAC and AFCEC (Unified Facilities Guide Specifications, on WBDG), read 2026-10-30.

What gauge is standing seam metal roofing?

The federal specification sets 24 gage steel, 0.023 inch thick, as the minimum for standing seam panels, and moves the whole roof to 22 gage, 0.030 inch, where the middle of the roof faces wind uplift of 60 psf or more. It says: “For minimum thickness of panel, UFC 3-110-03 allows minimum 0.6 mm 0.023 inch (24 gage) except where heavier gage is required to meet wind uplift criteria.” Source: U.S. Army Corps of Engineers, NAVFAC and AFCEC (Unified Facilities Guide Specifications, on WBDG), read 2026-10-30. “Provide material with a minimum, not including metallic coating thickness of 0.6 mm 0.023 inch thick (24 gage) minimum except when mid field of roof is subject to design wind uplift pressures of 3 kPa 60 psf or greater, entire roof system must have a minimum thickness of 0.8 mm 0.030 inch (22 gage).” Source: U.S. Army Corps of Engineers, NAVFAC and AFCEC (Unified Facilities Guide Specifications, on WBDG), read 2026-10-30. “However, a heavier section thickness of minimum 0.8 mm 0.030 inch (22 gage) may improve aesthetic with respect to oil canning.” Source: U.S. Army Corps of Engineers, NAVFAC and AFCEC (Unified Facilities Guide Specifications, on WBDG), read 2026-10-30.

How wide are standing seam metal roof panels?

Standing seam panels are usually about 16 inches wide and run in one piece from ridge to eave; the federal specification asks for at least 12 inches of coverage per sheet, and exposed-fastener panels are wider, about 3 feet. The sources say: “Standing seam roofs are custom-made and seamed to lock the panels together, with specialized tools on-site; individual panels, typically 16 inches wide, are normally installed as one long, continuous piece from the roof ridge to the eave.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30. “Sheets must provide not less than 300 mm 12 inches of coverage (width) in place.” Source: U.S. Army Corps of Engineers, NAVFAC and AFCEC (Unified Facilities Guide Specifications, on WBDG), read 2026-10-30. “Exposed fastener panels are factory-made, typically 3 feet wide and 8 to 16 feet long, ribbed to provide stiffness, and attached using color-matching, gasketed screws.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30.

Do standing seam metal roofs have exposed fasteners?

No screws go through the flat of a standing seam panel: the federal specification allows fasteners through the panels only at the ridge, eave, rakes, penetrations and end laps, with at least two fasteners in each hidden clip. The specification and the Department of Energy guide say: “Fasteners must not penetrate the panels except at the ridge, eave, rakes, penetrations, and end laps.” Source: U.S. Army Corps of Engineers, NAVFAC and AFCEC (Unified Facilities Guide Specifications, on WBDG), read 2026-10-30. “Attach panels to the structure with concealed clips incorporated into panel seams.” Source: U.S. Army Corps of Engineers, NAVFAC and AFCEC (Unified Facilities Guide Specifications, on WBDG), read 2026-10-30. “Provide a minimum of two fasteners per clip.” Source: U.S. Army Corps of Engineers, NAVFAC and AFCEC (Unified Facilities Guide Specifications, on WBDG), read 2026-10-30. “Standing seam panels are typically attached to corrosion-resistant clips that are attached to the roof using corrosion-resistant fasteners (screws) as specified by the manufacturer.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30.

Is a standing seam metal roof impact resistant?

Hail resistance depends on the product and the metal's thickness: the Department of Energy guide says heavier gauge metal resists hail better, and the IBHS Fortified hail supplement it cites asks for metal panels rated UL 2218 Class 4. The guide says: “Manufacturers rate products for impact resistance; some materials resist impact better than other materials, and heavier gauge metal resists damage from hail better than lighter gauge metal.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30. “The IBHS Fortified Hail Supplement to the IBHS High-Wind Standards requires metal roofing panels to be UL 2218 Class 4 impact-resistant.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30. “Impact-resistant roofing is also available to help protect against damage by windborne debris and hail.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30.

What is the wind rating of a standing seam metal roof?

A standing seam roof's wind rating is a design pressure from uplift tests such as ASTM E1592 and UL 580, and it holds only if the clips are the type, size and spacing tested; the Department of Energy guide shows panels that lifted because clips sat too far from the eave. The sources say: “Provide metal roof panel system that conforms to the requirements of ASTM E1592 and UL 580.” Source: U.S. Army Corps of Engineers, NAVFAC and AFCEC (Unified Facilities Guide Specifications, on WBDG), read 2026-10-30. “Uplift force due to wind action governs the design for panels.” Source: U.S. Army Corps of Engineers, NAVFAC and AFCEC (Unified Facilities Guide Specifications, on WBDG), read 2026-10-30. “Metal panel roof covering systems are rated by design pressure.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30. “However, it should be noted that the design pressure ratings are dependent on the proper attachment of the metal panel attachment, including the type, size, and spacing of fasteners or clips, and should comply with those requirements during installation.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30. “The clips holding these metal roofing panels were set too far from the roof eave (above the red line), and the panels were lifted in strong winds (Source: FEMA 2009).” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30.

What is the fire rating of a standing seam metal roof?

Seattle's residential code counts metal sheets on a noncombustible deck as a Class A roof, the highest of the three fire classes; over a wood deck, the Department of Energy guide says the roof usually needs a fire-resistant underlayment to reach Class A. They say: In Seattle, Washington, “Class A roof assemblies include ferrous or copper shingles or sheets, metal sheets and shingles, clay or concrete roof tile, or slate installed on noncombustible decks.” Source: City of Seattle, Department of Construction and Inspections, read 2026-10-30. “Metal roofs usually require a noncombustible roof deck or fire-resistant underlayment for the roof assembly to qualify as Class A.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30. “Class A has the highest resistance to fire, and unclassified have the least.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30.

Does a standing seam metal roof need to be vented?

In cold climates, or on clear nights when the roof cools below the air temperature, water can condense on the underside of the metal, so the Department of Energy guide calls for a vented attic or battens that vent the roof, over a continuous underlayment. It says: “In regions of cold or nighttime subcooling (where the roof temperature falls below air temperature), condensation can occur on the underside of the metal roofing.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30. “Adequate roof venting should be provided, either with a vented attic or venting of the roof assembly through the use of battens between the roof decking and roof cladding.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30. “To protect the roof sheathing should condensation occur, a continuous layer of roof underlayment (felt, synthetic underlayment, or membrane) is needed.” Source: U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory), read 2026-10-30.

Sources

• Resource guide: Metal Roofs — U.S. Department of Energy, Building America Solution Center (Pacific Northwest National Laboratory); published undated; read 2026-10-30.
• 2021 Seattle Residential Code, Chapter 9: Roof Assemblies (Washington) — City of Seattle, Department of Construction and Inspections; published 2021 edition; read 2026-10-30.
• UFGS-07 61 14: Steel Standing Seam Roofing — U.S. Army Corps of Engineers, NAVFAC and AFCEC (Unified Facilities Guide Specifications, on WBDG); published 2025-08; read 2026-10-30.