Copper Roof Pros and Cons for New England Homes

What are the advantages of a copper roof?

The biggest advantages of copper are longevity and low upkeep. Copper does not rust, and its patina protects the metal, so well-installed copper on churches and public buildings has served for a century or more with little beyond flashing and fastener repairs. Copper is also relatively light. A typical 16-ounce copper sheet weighs about 1 pound per square foot, far less than natural slate, which matters on older New England framing. It can be formed into curves, cones and domes that other materials cannot follow, which is why it shows up on turrets, eyebrow dormers and cupolas. Then there is appearance. Copper's color moves from bright to brown to green over the years, and on a Victorian, a Shingle Style house or a Federal-era home, that change can look like it was always meant to be there. Copper is also fully recyclable at the end of its service.

What are the disadvantages of a copper roof?

The main disadvantage is cost: copper is a commodity metal, its price moves with world markets, and it is among the most expensive residential roofing materials you can choose. Installation adds to that, because copper work calls for skilled sheet-metal mechanics, soldering and careful detailing. The second drawback is that copper changes. Some owners love the brown and green stages; others are disappointed when the bright penny look fades within the first year. You cannot reliably freeze it at one stage without ongoing coating maintenance. Third, copper affects what is around it. Runoff can stain light siding, trim and masonry, and water draining from copper onto aluminum or galvanized steel can corrode those metals. Copper also has to be fastened with compatible materials. Finally, copper is soft compared with steel, so it can dent from falling branches or careless foot traffic.

How does copper handle New England winters?

Copper handles cold, snow and freeze-thaw cycles well as a material, because it stays ductile at low temperatures and does not rust when meltwater sits on it. Winter problems on copper roofs are usually design problems rather than material failures. Smooth metal sheds snow, and copper is no exception. On a copper roof over a porch, entry or walkway, sliding snow and ice need to be considered at the design stage, and snow retention may be part of that conversation. Ice dams are a separate issue. They form when heat escaping from the living space melts snow on the upper roof and the water refreezes at the colder eaves. No roofing material prevents that by itself; insulation, air sealing and attic ventilation are what address it. Copper is sometimes used along eaves on older buildings, but the root cause still has to be fixed inside the house.

Is a copper roof a good choice on the coast?

Copper is generally a strong choice near salt water, because it does not rust and has a long record on coastal buildings. Salt air on Cape Cod, Nantucket, Martha's Vineyard, the North Shore, Newport and the Maine coast will push the patina along faster, which some owners treat as a bonus. The coastal caution is about the whole assembly, not the copper sheet. Fasteners, clips, flashings, gutters and anything the roof drains onto all need to be compatible with copper, or salt and moisture will speed up galvanic corrosion where dissimilar metals meet. Aluminum is the other common coastal choice for the same reason: it does not rust in salt air either. The difference between the two is mostly cost, appearance and how each one ages, not whether it will survive a waterfront location.

Is copper worth it, or is copper-colored aluminum a better fit?

Copper is worth it when the house, the budget and the owner's taste all point toward a roof meant to last generations and age visibly; for most whole-house projects, a copper-toned aluminum roof gives a similar first impression for far less. Interlock offers both, so this is a design choice rather than a sales pitch. Solid copper makes the most sense on landmark or historic homes, on small roofs such as bays, porches, cupolas and entries, and on projects where the patina is the point. Interlock's Copper Penny color on aluminum makes sense when you want a consistent copper tone that will not turn green or streak your siding. If your house is in a historic district, check with your local historic district commission before choosing either, since some commissions have specific views on metal roofing and on replacing original materials.

Common questions