Corrugated Roofing: Steel, Tin, and Corrugated Roofing Material Compared
Corrugated roofing is one of the most durable and cost-effective options for agricultural buildings, outbuildings, porches, and residential projects that prioritize performance over premium aesthetics. Corrugated steel roofing has been the standard for farm and industrial applications for over a century, and its profile has found its way into modern residential and commercial design. Corrugated tin roofing describes the same profile in older terminology, though true tin is rarely used today. Corrugated roofing material comes in multiple gauges, coatings, and profiles, and corrigated roofing (the common misspelling) searches all lead to the same products. This guide helps you choose the right corrugated product for your project.
Modern corrugated roofing is almost always steel, not tin. Galvanized or Galvalume-coated steel corrugated panels are the standard product you will find at most suppliers.
Corrugated Steel Roofing: Gauges, Coatings, and Profiles
Steel Gauge and Performance
Corrugated steel roofing is manufactured in 26-gauge and 29-gauge as the most common residential grades. 29-gauge corrugated steel roofing is the lightest weight product, appropriate for light agricultural uses, carports, and temporary structures. 26-gauge corrugated steel roofing handles heavier wind and snow loads and is appropriate for primary structures including homes and commercial buildings. The lower the gauge number, the thicker and stronger the steel. In hail-prone areas, 26-gauge or heavier is recommended for primary residence corrugated roofing material.
Galvalume coating on corrugated steel roofing panels, a zinc-aluminum alloy applied to the steel surface, provides better corrosion resistance than traditional galvanized (zinc only) coating. In coastal or high-humidity environments, Galvalume-coated corrugated steel roofing outlasts galvanized product significantly. Most quality corrugated roofing material today uses Galvalume as the base coating, with optional paint finishes on top.
Corrugated Roofing Profiles
The standard corrugated profile has rounded ridges and valleys spaced 2.67 inches apart. This profile is sometimes called “2-2/3” or standard corrugated. Other ribbed profiles like the R-panel have wider, squarer ribs and are often called corrugated tin roofing colloquially even though the products are different. The 2.5-inch pitch corrugated profile is slightly wider than standard and provides better drainage on low-slope installations. Check the manufacturer’s minimum slope recommendation for the profile you select, as corrugated panels require a minimum pitch to drain properly without leaking at lap joints.
Corrugated Tin Roofing: History and What’s Available Today
What people call corrugated tin roofing is almost always steel. Actual tin plate roofing was common in the 19th century but was phased out as galvanized steel became cheaper and more available. The term persists in rural and regional language. If you encounter a building with truly corrugated tin roofing, it is likely historic and worth consulting a preservation specialist before replacement.
Modern corrugated roofing material described as tin is steel with a galvanized or Galvalume coating. It performs identically to products marketed as corrugated steel roofing. Do not pay a premium for a product marketed as corrugated tin unless you specifically need an antique or historically accurate finish.
Installing Corrugated Roofing Material
Corrugated roofing material installs with exposed fasteners driven through the high points of the corrugations into the structural members below. Use hex-head self-drilling screws with neoprene washers to create a watertight seal at each fastener. Do not overdrive the screws or the neoprene washer will compress and lose its sealing function. Side laps between adjacent panels should overlap one full corrugation minimum. End laps on slope transitions should overlap 6 inches minimum, with lap sealant tape applied between panel layers for watertight performance.
Minimum slope for most corrugated roofing material is 3:12. Some manufacturers approve 2:12 with extra lap precautions and sealant at all laps. Below 2:12, corrugated panels are not appropriate, and standing seam or membrane roofing should be used instead.
Key Takeaways
Corrugated steel roofing in 26-gauge with Galvalume coating performs reliably for decades with minimal maintenance. Corrugated tin roofing is historical terminology for what is now galvanized or Galvalume steel. Use exposed fasteners with neoprene washers, follow minimum slope requirements, and choose 26-gauge over 29-gauge for any primary residential or commercial structure. For pricing and profile selection guidance on a specific corrugated roofing project, consult a licensed roofing contractor or metal panel supplier familiar with your region and application.
