Topic: Gutters and Downspouts
For the purpose of these guidelines, gutters and downspouts refer to systems that are built into or attached to a structure (or auxiliary structure garage, canopy, etc.) to facilitate the orderly conveyance of rainwater or melting snow from the roof.
The Secretary of the Interior’s Standards for Rehabilitation and Guidelines for rehabilitation state that:
“Deteriorated historic features shall be repaired rather than replaced. Where the severity of deterioration requires replacement of a distinctive feature, the new feature shall match the old in design, color, texture, and other visual qualities and, where possible, materials.”
The Secretary of the Interior’s Standards for Rehabilitation and Guidelines for Rehabilitating historic Buildings recommend against:
“Removing an architectural metal that is un-repairable and not replacing it; or replacing it with a new architectural metal feature that does not convey the same visual appearance.”
The following guidelines concerning gutters and downspouts are provided to assist in the interpretation and application of the Secretary of the Interior’s Standards and Guidelines.
The place and style of gutters on historic homes and other buildings varies greatly. Some buildings were clearly built with gutters and downspouts. These systems may be needed to carry water away from foundations and avoid infiltration of water into basements. On the other hand, gutters can create hazards in the winter as they build up with ice and carry tremendous weight. For adequate functioning in both summer and winter, gutters and downspouts must be designed in accordance with accepted standards for size, placement, and method of attachment.
Some structures were designed to carry water off the roof edge where it would drip to the ground, and no gutter/downspout system was used. In other structures, gutters were built in. In some, they were mounted at the roof edge. Some types of gutter styles, available at the time of original construction, may not be common today.
Repairing or replacing original style gutters can be an expensive proposition, whether they are the built-in or add-on type. When gutters are built in, the normal appropriate repair is to rebuild the original built-in style, which will involve custom work. When gutters are the add-on type, they were usually not integral to the architectural style of the structure and may be easier to repair or replace.
The first consideration with add-on style gutters is to decide whether they are necessary at all. In many cases, simply re-grading and removing excess vegetation around the house in order to direct run-off away from the foundation will make gutters and downspouts unnecessary. Therefore, Re-grading should always be considered. Not every house was intended to, or should, have gutters and downspouts.
Proper gutter and downspout systems are designed to accommodate the volume of water collected on the roof during a heavy rain. The volume of water to be drained away dictates the size of gutters and downspouts. Using a system which is too small will be a poor investment, since it will not function properly and may be easily damaged in heavy rains and in winter ice conditions. There are standards for the appropriate size of gutter needed in relation to the size of the roof that can be obtained from contractors and architects. In certain cases, the detailing on the eaves of the house may also dictate a larger size gutter than what is actually needed for the water volume in order to be compatible with the size and placement of other details at and near the roof edge.
Shape, Style and Properties
Built-in, “K Style” and “Half Round” gutters all have a historical presence on homes in historic districts depending on the architectural design of the roof/eaves of the house. The appropriate application of any gutter system is directly related to the overall roof design to ensure the practical long-term success and economy of the roof drainage system.
- “K Style” Gutters Designed Originally for Roofs with Flat Vertical Edges
These roofs are commonly seen on Colonial Revival and other structures popular from the 1910’s through the 1930’s. The “K Style” gutter is shaped to be mounted against the flat fascia board, and to mimic classical crown moldings. In effect, it replaces the detailing common on tapered roof edges discussed under (2) below. The plain flat back of the “K Style” makes it appropriate only when placed against the flat fascia board original to many “revival” style houses. It is not appropriate in situations where it needs to hang free beneath the roof edge.
Original crown moldings or other detailing should not be removed in order to fit a “K Style” gutter against a flat vertical board. Installations rely on a vertical fascia board on the eave to support the base of the gutter. This will allow the gutter to be pitched along its length for drainage. The drawing illustrates a “K Style” gutter installation appropriate to a house with vertical fascia boards on the eaves.
Eaves Without Gutters or With Half-Round Gutters
Two types of eaves which may never have had gutters are common in the historic districts of Grand Rapids: tapered eaves and eaves with open rafter tails. They are designed to allow water to drip off the edge without flowing backward and down the face of the building.
In cases where a gutter is used, the half-round design is normally appropriate because it is intended to hang free of the trim details and rafter ends.
In some cases, the open rafter tail is cut vertically (parallel to the side of the house). In such cases, it might be physically possible, but NOT appropriate to attach a flat vertical board to the rafter tails and then attach a “K Style” gutter. This would normally be unacceptable.
Two types of built-in gutters, which are common in the historic districts, are illustrated. One type is visible from the ground because it is built on top of the roof surface. The other type is largely out of sight because it is built within the eave structure below the level of the roof. These allow all of the detailing of the roof edge to be seen.
Built-in gutters that are integral to a historic property are an important characteristic of the property and should be preserved.
Rectangular downspouts typically accompany “K Style” gutters. Round downspouts are typical to Half-round and built-in gutter systems.
Built-in gutters are usually constructed of wood, covered in metal. Other gutters should be made of metal (usually galvanized steel, copper or aluminum) and should be of adequate strength for the installation intended. Seams should be minimized. Plastic or vinyl materials are generally not appropriate.
Claims for exemption from this policy because of economic hardship must be based on the cost of the work in relation to the market value of the property after rehabilitation. The fact that an appropriate solution is significantly more expensive than an inappropriate one does not, in itself, indicate an economic hardship.
The Commission generally does not require specific materials to be used, such as copper, as it often was on historic properties due to its durability. Unfortunately, copper is now more expensive than available alternatives. Galvanized steel and aluminum gutters may be strong enough to handle the water volume in many cases. Vinyl will usually not be strong enough to handle water and ice loads on historic houses.
As noted earlier, costs can sometimes be saved by dispensing with gutters altogether.
In some cases, the Commission may approve a solution that is structurally adequate but otherwise inappropriate for areas of a building that are not very visible if cost is a problem, while requiring the appropriate solution for more visible areas.
It is also noted, however, that visually inappropriate solutions are often structurally inadequate as well, because the gutter cannot be supported in the manner for which it was designed. This is often true of the “K Style” gutter when it is not attached to a vertical fascia board but is hung in the way half round gutters are designed to be mounted. The “K-Style” may need to be of heavier aluminum and/or be supported with more hangers than usual to be strong enough in such an application.
These guidelines were approved on January 11, 2001, by the Michigan State Historic Preservation Office under the provisions of Michigan’s Local Historic District Act (1970 PA 169, §5(3); MCL 399.205)
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