Preservation by Prevention: Gutters and Downspouts

A gargoyle with a spout in its mouth eases the flow of water out of the gutters.

A gargoyle with a spout in its mouth eases the flow of water out of the gutters.

Gutters and downspouts are critical components of a building’s water protection system because they are the most effective method of collecting rainwater from the roof and directing it away from the building’s foundation. Gutters have existed for thousands of years in one form or another, and they probably have always necessitated a hated task of building ownership – cleaning. In addition to cleaning, periodic maintenance of your gutters is necessary to ensure that they keep the water flowing and out of your basement.

Gutter History

The most common gutter style in America today is the aluminum, K-style gutter, which is formed to fit flush against the eaves with a contoured profile turned to the outside of the building. These rolled metal gutters, however, have only been available in mass-produced form since the Industrial Revolution of the 19th century. Rolled steel gutters were initially the most popular type of mass-produced gutter, with aluminum gutters taking over the market in the 20th century. These gutters, which hang from the eaves, are called external – or hanging – gutters.

This wooden gutter from a house in the Alps was cut from a log.

This wooden gutter from a house in the Alps was cut from a log.

Prior to the advent of the K-style gutter and until the 1950s, the most common external gutter was the half-round gutter. Half-round gutters were traditionally made from wood and copper, which could be lined with lead to increase their water resistance. Half-round gutters remain available and are most commonly used in historic restoration projects and for custom building. They are somewhat more expensive than K-style gutters, but they are more resistant to the detrimental effects of ice and snow and move water efficiently.

Many historic buildings use internal gutters instead of external ones. Often called box gutters, internal gutters are recessed troughs constructed in the plane of the roof near the eaves. Though originally constructed of wood, advances in construction practices made it standard to line them with metal, often lead. Box gutters are advantageous because they usually have no effect on the property’s appearance since the interrupted roof plane is not visible from the ground.

A scupper brings water from gutters to a decorative leader box and leader, or downspout.

A scupper brings water from gutters to a decorative leader box and leader, or downspout.

Gargoyles and other devices originally provided a way for water to exit the gutter, allowing gravity to carry it to the ground. A major advance in gutter technology was the addition of downspouts – or leaders – to the gutter system. It has been speculated that the first downspout installed in the United Kingdom was at the Tower of London in 1240, in an effort to protect a new coat of whitewash. Downspouts from internal gutters often have decorative leader boxes where the scupper brings water from the gutter to an external downspout. Downspouts may be internal to the building, running through the walls and into a cistern or underground drainage system. Internal gutters and downspouts are risky installations because leaks send water into the roof, ceilings, or walls, significantly increasing the importance of regularly maintaining these systems.

Gutter Maintenance

Gutters and downspouts require regular maintenance to ensure that they are not blocked and are watertight. Gutters need to be kept free of leaves, branches, pine needles, and other debris from the roof. While these objects may not prevent water from flowing along the gutter until it is totally clogged, the debris can quickly block the junction between the downspout and gutter, effectively acting like a stopper in a drain. Downspouts can be checked for clogs by running water from a hose down them. Clogs in downspouts can be broken up and cleaned out with a long probe. Where downspouts meet the ground, they should empty into pans or tubes that direct water down a grade sloped away from the foundation to prevent pooling near the foundation.

Regular gutter maintenance also requires making sure that the gutters are pitched properly and that all joints in the gutters and downspouts – and between gutters and downspouts – are tight and sealed. This is particularly important for internal gutters, where leaks along the length of the gutter can send water directly into the building’s structure. The hangers or brackets holding external gutters along the eaves should also be checked periodically.

Snow guards break up the snow as it slides off of this slate roof.

Snow guards break up the snow as it slides off of this slate roof.

In colder climates, snow guards along the roof edge are a good idea as they prevent gutters from absorbing the brute force of snow sliding off the roof. Gutters in cold climates can also fill with ice, making them ineffective as water from melting snow comes off the roof. Instead of flowing through the gutter and out the downspout, melted snow rolls over the ice, becomes super-cooled, and forms beautiful but treacherous icicles along the eaves. The weight of the ice can pull the gutters off the building. And, while gutters do not cause ice dams, they can become part of an ice dam because of their location along the colder eaves. If you do get an ice dam on your roof, one specialist recommends melting a hole in it with hot water from your water heater – provided by connecting a hose to the drain cock – to release the melted snow behind the ice dam.

An ice dam and gutter ice have damaged this K-style gutter.

An ice dam and gutter ice have damaged this K-style gutter.

Keeping your gutters clean and in good repair will do a lot to protect your historic home. Functional gutters and downspouts keep water from washing down the wall of the building, which prevents deterioration of the painted sheathing and saturation of all building materials. Gutters and downspouts also help keep water out of your basement and away from the foundation, protecting the building’s structural stability. In short – though we may hate the tradition, it is critical to get up on a ladder to clean and repair your gutters every six months.

Sources

Harris, Cyril M., ed. Illustrated Dictionary of Historic Architecture. New York: Dover Publications, Inc., 1977.

Morrison, Jim. “Inspector’s Corner: Rain Gutters and Ice Dams … by Jim Morrison.” My Realtor Karina. (Accessed August 19, 2009).

The Old House Web. “Gutters and Down Spouts.” Old House Web. (Accessed August 18, 2009).

Park, Sharon C. “Preservation Brief 31: Mothballing Historic Buildings.” National Park Service. (Accessed August 18, 2009).

Park, Sharon C. “Preservation Brief 39: Holding the Line, Controlling Unwanted Moisture in Historic Buildings.” National Park Service. (Accessed August 18, 2009).

The Society for the Protection of Ancient Buildings. “A Brief History of Gutters.” The Society for the Protection of Ancient Buildings. (Accessed August 18, 2009).

Stevens, Ned. “History of Gutters.” Ned Steven Gutter Cleaning. (Accessed August 18, 2009).

Young, Robert A. Historic Preservation Technology. Hoboken, New Jersey: John Wiley & Sons, 2008.

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