Most architects agree that the best rain gutters are made of copper, with stainless steel perhaps a close second. Copper is so durable that it is used on most government buildings that have lifetimes measured in centuries, not years. Unfortunately, Hemlock Lodge at Natural Bridge State Resort Park was not designed to last centuries. It is a more humble structure, perched on a hillside in eastern Kentucky, with a useful life rated in decades.
Because Hemlock Lodge is not some grand historical structure, many people think that it was not wise use of public monies to adorn it with what might be the largest, most beautiful, and most expensive gutters in Kentucky. The cost was around a quarter-million dollars and people wonder why this money was not put to better use, such as more patrolling of Natural Bridge Cave to minimize the (alleged) problems of vandalism.
It's obviously in the taxpayer's best interest that public buildings to be constructed with low-maintenance materials, but when copper is selling at the highest price in U.S. history, it's use for guttering seems questionable. Most commercial buildings are fitted with heavy gauge, primary aluminum gutters. When installed properly by professionals, this commercial grade aluminum guttering can be expected to last for decades, and possibly a century or more. After all, World War II airplanes are still flying and their skins are made of aluminum.
The bad reputation that often accompanies aluminum is mainly due to the use of thin, lower-grade aluminum in many residential gutter systems Often improperly installed by under-trained contractors, these inferior gutters fail prematurely because of low mechanical strength and poor chemical resistance. Aluminum alloys are more brittle than copper, and their coefficient of expansion is greater, so more skill is required to properly install aluminum gutters.
In most environments, copper and aluminum both have excellent resistance to atmospheric contaminants. The biggest enemy of aluminum is mercury, but in most places in the world - and certainly in eastern Kentucky - mercury levels in the air are so low that the life of aluminum gutters will not be shortened because of it. Some metallurgists suggest that the life of discarded soft drink cans could be as much as 10,000 years, so we can expect at least a few decades out of properly installed aluminum gutters!
The use of copper for gutters, rather than aluminum, equates to half the carbon footprint, and this seems appropriate in a place dedicated to the preservation of natural resources. But this benefit of copper over aluminum will, unfortunately, be quickly offset by the thousands of aluminum soft drink cans annually sold in the Park.
In any event, justified or not, Hemlock Lodge is now outfitted with hundreds of feet beautiful copper gutters, flashing, hangers, and downspouts.. Park management will now have to decide whether extra night patrols will be needed in order to keep copper thieves from stealing it!