By Anne Schade, Revere Copper
However, in the universe of rainwater goods, copper occupies only a relatively small segment of the market. Further, the segment that copper occupies varies considerably from region to region and, even within a region the percent of gutters formed from copper will vary considerably. Why is this?
Several things contribute to the answer:
- Architectural style or preference
- Regional traditions and acceptance
- Product availability
- Myths and misconceptions regarding copper
- Local building codes
And, perhaps the most often cited reason:
Architectural style or preference: While the natural weathering of copper from bright and shiny “new-penny,” through its oxidized brown and statuary colors, to a mature green patina compliments many designs and styles, such transformations do not “work well” on all structures. There are cases where it is preferable to paint gutters to match the fascia so they “blend and hide.” While copper can certainly be painted to match almost any color or hue, why use copper when other metals “hold” paint as well.
Regional traditions and acceptance: Although there are buildings with copper gutters in every state (and probably several in every major population center), the tradition of copper craftsmanship is strongest in New England. There are many reasons for this; not the least of which is that the first copper rolling mill in North America was established by Paul Revere in Canton, Mass., in 1801.
New England, however, is not the only region where copper rainwater goods are popular. Other areas where copper is readily accepted include: the Coastal States from New England to Florida to Texas and, from the Pacific Northwest to southern California. The use of copper also is well established in the “old industrial corridor” from Boston through New York, Pennsylvania, Ohio, Michigan, Indiana, to Chicago.
Likewise, there is a tradition of copper use in Canada from Halifax, through the Maritimes, Southern Quebec to Eastern Ontario. There is also a “copper island” in and around Vancouver.
This is not to say that copper is any more limited to these areas than is Spanish tile limited to Southern California — it is just that these are areas where it is easy to locate copper installations.
Product availability: Although major manufacturers of rainwater goods ship their products to distributors and installers throughout the United States and, local contractors can form copper gutters on brakes and roll-forming machinery, it can be difficult to purchase copper gutters.
Why? The answer is like the question regarding the chicken and the egg: there is no demand for copper gutters so building supply houses do not stock them or the copper sheets and “gutter coils” from which they are made. Then, since there are no copper gutters available, few architects or owners think to ask for them and fewer contractors offer them.
Myths and misconceptions regarding copper: It is amazing how many people in the construction field believe:
- Copper expands more than other metals
- Copper is a soft, weak metal
- Copper attracts lightning
NONE of the above are correct!
The coefficient of expansion for copper (0.0000098 per degree F) is the same as that of type 302/304 stainless steel; the coefficient for aluminum is 50 percent greater (0.0000138) while coefficient for zinc is almost double that of copper (0.0000164). Of the materials commonly used for gutters, only mild steel (galvanized, Galvalume, etc.) has a lower coefficient of expansion than copper (0.0000070).
When subjected to temperature changes gutters must transfer expansion movement from a fixed point (outlet or downspout) to a point of release (an expansion joint) without buckling. The ability of a gutter to do this is a function of its columnar strength.
During the early 1940’s Revere Copper of Rome, N.Y., conducted tests that established the columnar strength of a gutter is dependent on its temper, thickness and shape. When a copper gutter is properly designed and correctly installed, it has more than enough strength to withstand the forces of nature without failure. (A complete description of the tests conducted, results, plus suggestions for the design and installation of copper gutters can be found in Revere Copper Products sheet copper design manual Copper and Common Sense.
It is true that copper conducts electricity (as does aluminum) but, it does NOT attract it! If a copper roof is struck by lightning, it is typically because it is the tallest/highest item in the immediate area — not because it is copper.
Local building codes: In a well-intentioned but, completely misguided effort to protect the environment, at least one western municipality passed an ordinance to prohibit the use of copper for roofing and rainwater goods. While the ordinance gained widespread support among environmentalists, it was based entirely on supposition and wholly unsupported by scientific tests.
Subsequent tests, which were sponsored by the international copper industry, developed a model that can accurately predict the amount and fate of copper in run-off from architectural applications. However, municipalities that have enacted anti-copper regulations have been reluctant to re-visit their earlier decisions. As a result, there are locations where new copper gutters cannot be installed.
Cost: Perhaps, more accurately, the perception of high costs is, by far, the single greatest obstacle to the greater use of copper for gutters.
Admittedly, copper gutters are more expensive (initially) than their counterparts made from painted steel and/or aluminum. But, when it is considered that copper may well be the only material that can provide 50- to 100-years of maintenance-free service and that copper has a high salvage value, is there really that much difference in cost? Actually, a cost savings is more likely to be seen.
The case for Copper Gutters
So having explored why there are not more copper gutters, let’s take a look at some of the reasons a contractor, architect and building owner should insist on copper rainwater goods: durability, compatibility, self-healing properties, harsh environmental exposures, multiple sources and methods of fabrication, large selection of products and styles, custom designs, environmental issues, recycled value and, of course, cost.
Durability: With the possible exceptions of adobe, thatch and stone, no building material in common use today has a longer or better “track record” than copper. It is unclear when copper was first used for gutters but, at least 3,000 years before the great cathedrals of Europe were rising (many with copper roof, flashings, and gutters), the Egyptians used “wrought copper pipe” to transport water at a burial complex located in Abusir in Northern Egypt. (The pipes, believed to date from the reign of King Sahure, the second King of Egypt’s 5th Dynasty, who ruled from 2517 to 2505 B.C., were discovered during a 1994 archeological dig.)
Compatibility: When selecting roof flashings and gutters there are at least two “compatibility issues” to consider:
1) Will the expected life of the flashings and gutter be at least equal that of the roof?
2) Is run-off from the roof (and flashings) compatible with the gutter?
What is the sense in installing a “high-end” slate (real or simulated), tile, architectural-grade shingle or other 50- to 100- (or more) year roof, if the flashings are made of a material that is subject to corrosion (unless it is maintained with paint or other coating)?
What is the best material for flashing high-end roofs? — Hands down it is copper!
Copper is a “noble” metal at the high-end of the galvanic series. In this position, copper is highly resistant to corrosion from other materials. However, run-off from copper will attack metals at the lower end of the series: aluminum, mild steel, galvanized steel, Galvalume and zinc.
Self-healing properties: Unlike painted products, if left alone, the aesthetics of copper are “self-healing.”
Scratches, nicks and other physical damage that expose the unprotected base metal of aluminum or steel gutters must be repaired (field painted or replaced) or corrosion may follow. Similar damage to copper rainwater goods is not a problem.
Within a very short time period (hours), of being exposed to the atmosphere copper begins to oxidize. As time progresses the oxide film builds and thickens to protect the copper from further deterioration. Depending upon the severity of the scratch or “ding,” age of the copper, how far its natural patination process has progressed and the local weathering factors, the damage may disappear within a few weeks or months.
The important thing, however, is that copper requires no help or maintenance to preserve its aesthetics and weather-proofing function.
Harsh environmental exposures: No metal is better suited for use in marine and harsh urban or industrial environments than copper. Rather than review long dissertations on the tests to determine the durability of copper just consider the Statue of Liberty.
On October 28, 2011, Lady Liberty will celebrate her official 125th birthday. For all that time she has stood in one of the harshest urban, industrial, marine environments in the world — New York Harbor.
Multiple sources and methods of fabrication: While some architects, building owners and contractors may be unaware of products and services available, there are many manufacturers and distributors of copper gutters and downspouts throughout North America.
Although they may not be aware of it, any contractor who has a jobsite roll former for producing seamless half-round or K-style gutters can manufacturer copper gutters. In addition, sheet metal contractors can form most rainwater goods using nothing more than a brake and hand tools. (Although it may require more work and skill, a simple hand, box-brake is sufficient for most shapes. An “auto-brake” may speed production but isn’t normally required to make copper gutter sections.)
It is unlikely that you will find copper gutters in a “Big Box” building supply store. But, go online and Google “copper gutters” — you will be amazed at the results. [I just did and got “About 613,000 results (0.11 seconds).]
Large selection of products and styles: The majority of copper rainwater goods are fabricated from plain, “red” copper. However, for aesthetic purposes other finishes are available from the copper mills. These include tin/zinc alloy coated copper and pre-oxidized copper.
Tin/zinc alloy coated copper (Revere FreedomGray) is an ideal product where a durable, gray, environmental and human health friendly gutter system is wanted. The soft, “weathered pewter” color of FreedomGray is somewhat lighter and brighter than weathered lead but, FreedomGray and the run-off from it are “lead-free.” Certainly this should be a consideration when designing and installing rainwater collection and control systems on schools, public buildings, residences, etc.
Revere ContinentalBronze pre-oxidized copper is an excellent choice for gutters and downspouts that must appear to have a uniformly aged color (statuary bronze) at installation or shortly after.
Eventually all newly exposed plain or “red” copper will develop a uniform brown or bronze coloration, the rate at which this color forms is dependent on local (micro) environmental conditions and degree or severity of exposure. All other things being equal, sloping surfaces (roofs) age faster than vertical surfaces (walls and downspouts) which, in turn, weather faster than soffits, the bottoms of gutters, and other “reverse slope” applications.
While the natural oxidation process used to create ContinentalBronze only “turns the clock ahead,” in the case of gutter bottoms, downspouts and other “sheltered” locations, the time may be significant.
Custom designs: No architectural metal is easier to cut, bend and solder than copper. As a result, architectural sheet metal shops will be happy to produce custom gutters, collection boxes, leader heads, downspouts and other decorative and functional rainwater control devices out of copper. Many contractors not only work with copper as a business, but design and create interesting artworks as a hobby!
If an architect is not involved, an owner or contractor need spend only a few minutes on line to locate many manufacturers of “custom” copper goods who are more than happy to ship “ready-to-install” anywhere. There is no reason today a remote lodge in the rainforests of Costa Rica cannot have the same quality-crafted rainwater control system as a mansion in Newport, R.I.
Environmental issues: Despite myths and misconceptions to the contrary, architectural copper is an environmentally friendly material. In fact, because of its source, manufacturing process, durability, recyclable properties and appearance, copper has been referred to as “The first green metal” (literally and figuratively).
The architectural copper produced by Revere Copper Products, Inc. for use in the fabrication of rainwater goods contains “90- to 95-percent recycled copper” (feedstock), harvested from sources within 500 miles of the Revere plant in Rome, N.Y.
Recycled value: Recycling and reusing copper and copper alloys is not a new, 21st century idea.
Although their existence was documented by Pliny the Elder, no trace of the bronze plates that covered the Colossus of Rhodes have been found. Why? Because the metal was salvaged, melted and re-used. (According to at least one account, when the Arabs captured Rhodes in 654, the remains were sold to a Jewish merchant from Edessa.)
From the Middle Ages until at least the early 19th century, in times of war it was common to melt copper from roofs, church bells and other items to make cannons. After a war the cannons were melted and bells re-cast.
This continuous process of use, recycle and re-use of copper is not only possible but also practical because copper is easy to work with and does not “down-cycle.” Smelting and refining is not required to convert clean, “bare-bright” copper “scrap” into new, high quality sheets and coils for the construction, electrical and other markets.
As a result, nearly all of the copper that has been mined (from the Bronze Age to the present) is believed to still be “in service” today.
Cost: If a copper drainage system is correctly designed and correctly installed, it can provide many decades (centuries?) of maintenance-free and trouble-free service. The first cost of the system will be its last cost.
When the structure serves it useful life and is demolished or is modified in such a manner that the original rainwater system is of no further use, the copper will be salvaged and recycled. While it is impossible to predict the future value of copper, in the past, when 50- to 100-year old copper was recycled its value often exceeded its original cost.
For assistance in the design, specification, and installation of copper rainwater systems contact firstname.lastname@example.org
In conclusion: Rainwater goods of copper are not only practical and aesthetically pleasing; they are also cost effective and environmentally sound. Further, copper gutters can be an integral component of a rainwater harvesting system. In the case of existing, institutional or commercial buildings, simply rerouting the existing down-pipes from a storm sewer to a properly sized storage tank can provide thousands of gallons of water suitable for landscaping, sanitary and other gray-water applications.
Anne Schade is the manager, architectural services at Revere Copper Products, Rome, N.Y.