Standing Seam or Metal Shingles: Which Fits a North Carolina Home?

Standing seam is a roof made of long metal panels that run from the eave to the ridge, joined along their edges by raised seams that stand an inch or more above the roof surface. The panels are usually held down by concealed clips under the seams, so there are no exposed fasteners in the field of the roof. The look is clean, vertical and modern.

Metal shingles are smaller panels, each formed to show several slates, shingles, shakes or tiles. They are installed in overlapping courses from the eaves up, like a traditional roof. On interlocking systems such as Interlock aluminum shingles, each panel locks to its neighbors on all four sides and the fasteners sit hidden under the next course. The look is traditional; from the street, a slate-profile metal roof reads as slate rather than as metal.

Both can be made from steel or aluminum, and both go over a solid deck with underlayment on homes. Interlock offers both: four aluminum shingle profiles and an aluminum Standing Seam system. Our guide to Interlock roof profiles shows each one.

Standing seam looks right on modern farmhouses, contemporary homes, mountain and lake houses, and on porch roofs, bay windows and additions where a crisp metal accent sets off a shingle roof. It is a popular choice on new construction around Raleigh, Wake Forest and the Charlotte suburbs, and on lake homes at Jordan Lake, Falls Lake and Lake Norman.

Metal shingles look right on the traditional houses that make up most of North Carolina's older neighborhoods: brick Colonial Revival and Georgian homes, Craftsman bungalows in Durham and Raleigh, Victorian homes in Wilmington and New Bern, and two-story subdivision homes where an HOA expects a shingle-style roof. A slate or cedar profile keeps the house looking like itself.

Many owners combine the two: metal shingles on the main roof and standing seam on the front porch. That mix is common and usually looks deliberate. If you combine metals, keep copper from draining onto aluminum or galvanized parts, and get HOA approval for both materials. See HOA approval for a metal roof.

Standing seam handles low slopes better than metal shingles. Because the seams are raised well above the water line and the panels run continuously down the roof, properly designed standing seam systems can be used on much lower pitches than overlapping shingle-style roofs. The model residential code sets separate minimum slopes for different metal roof types, and standing seam systems are allowed on the flattest of them.

Interlock aluminum shingles need a roof pitch of at least 3/12, meaning three inches of rise for every 12 inches of run. Most North Carolina homes have main roofs well above that, but many porches, sunrooms, shed dormers and rear additions are flatter. On those sections, standing seam or a low-slope membrane is the usual answer.

If your house has several roof pitches, a good estimate will identify each one and say which covering goes where. Ask the contractor to measure, not guess. For how the code treats reroofing in general, see NC Residential Code and reroofing.

Metal expands when it heats up and contracts when it cools, and North Carolina summers put roofs through big daily swings. The U.S. Department of Energy notes that conventional roofs can reach 150°F or more on a sunny summer afternoon. A long standing seam panel moves noticeably along its length between a hot afternoon and a cool night, and aluminum expands more than steel for the same temperature change.

Good standing seam systems handle that with sliding or floating clips that let the panel move without stressing the fasteners. Poorly designed or poorly installed systems can show oil canning, the visible waviness in flat panel areas, or can work their fasteners loose over time. Panel length, clip type and installation all matter, so ask about them directly.

Metal shingles deal with expansion differently. Each panel is small, so the movement is spread across many joints instead of building up along a long panel. That is one reason shingle-style metal roofs rarely show oil canning. For the heat side of the question, see does a metal roof make a house hotter and metal roof colors for NC heat.

Both systems can perform well in wind when they are tested and installed to the manufacturer's specification, and both can fail at the edges when they are not. Ask for the published wind rating of the exact system. Interlock aluminum shingles are rated for winds up to 120 mph when installed to manufacturer specification; Standing Seam has its own documentation, so request it separately. ICC-ES report ESR-1790 covers the Interlock shingle, slate, shake and tile profiles, not Standing Seam. On the coast, the permit office or engineer sets the required wind design for the house.

Whichever system you choose, the edges deserve the most attention. FEMA's coastal guidance notes that wind uplift is greatest at the corners, then along the perimeter, then in the field of a roof. Ask how the eave, rake and ridge trim will be fastened, and whether the fastening schedule tightens up in those zones. Most metal roof failures in storms start at a loose trim piece, not in the middle of a panel.

Salt air matters more than profile near the ocean. Steel standing seam depends on a zinc-based coating that salt wears down, while aluminum does not rust. See aluminum vs steel on the NC coast.

Repairs differ too. A damaged standing seam panel often has to be replaced along its full length, which can mean working up to the ridge. Metal shingles are smaller, so damage tends to be confined to a smaller area. Either repair belongs with a roofer who has the right trim and panels.

Costs depend on the specific system, metal, gauge, roof shape and tear-off, so there is no reliable rule that one always costs more. Aluminum generally costs more than steel as a raw material, but it avoids rust near the coast. Complex roofs with many valleys, dormers and hips add labor to both. Metal Roof NC's rule of thumb is that an Interlock aluminum roof typically costs about 2.5 to 3 times a traditional asphalt-shingle roof. Prices vary job to job with roof size, pitch, tear-off and other conditions, and an on-site estimate is required for an accurate price.

Noise is mostly about what is under the metal. On a house, both systems go over a solid deck with underlayment, plus attic insulation and a ceiling, which keeps rain noise close to that of other roofs. Standing seam over open framing, as on a barn or carport, is the loud version people remember. See metal roof noise in rain.

Decide on looks and roof shape first, then compare the systems on paper. A simple way to sort it:

• Choose metal shingles for traditional houses, HOA communities that expect a shingle-style roof, and owners who want the look of slate or cedar.
• Choose standing seam for modern designs, low-slope sections and accent roofs.
• Combine them when the main roof is traditional and the porch or addition is low-slope.
• Choose aluminum for either system near salt water.

Metal Roof NC, an authorized Interlock aluminum roofing dealer, installs both Interlock aluminum shingles and standing seam metal roofing across the Triangle, Charlotte, the Triad and the coast. Ask for both on one estimate if you are unsure, and ask to see finished roofs of each type in person. More on our metal shingles and aluminum roofing pages.