Preserving Original Roof Features of Your Historic Building
Milwaukee County. Slate roofs (as seen in this photo) are not only a character-defining feature of your house, but also have life spans of up to 100 years. Source: WHS - State Historic Preservation Office.
The roof on your historic house or building was designed to fulfill your roof’s main job: to protect your whole building from water penetration. Any major change you make to your roof configuration could cause drainage issues that result in moisture damage to your building. The original roof configuration is also an important character-defining feature of your historic house or commercial building. Any alteration you make to the original shape of your roof will dramatically change your building’s appearance and compromise its historic character. This loss of historic character will also have an impact on the appearance of your street block.
To retain the integrity of your roof, you should preserve and maintain all elements of your original roof, including its design, materials, features and the flashing along the masonry or wood frame walls.
Preserve Your Original Roof Design and Materials
Milwaukee County. An example of a hipped roof. Source: WHS - State Historic Preservation Office.
The earliest 19th century Wisconsin houses and buildings were designed primarily with a hipped roof or a gable roof. From the 1860s to the 1880s, Mansard roof forms were popular on houses and buildings built in the Second Empire style. Other roof forms used for historic houses included gambrel, pyramidal and conical as well as variations of hipped and gable designs. By the 1880s and throughout the 20th century, most commercial buildings were constructed with a flat, sloping roof.
Mitchell Building, 1876
Milwaukee, Wisconsin. Mansard roofs are a common characteristic of the Second-Empire building style as seen at the Mitchell Building. Source: WHS - State Historic Preservation Office. View the property record: AHI 27229
The earliest roofs were covered with materials such as wood shingles, slate and metal. Wood shingle use was gradually phased out in favor of more fireproof materials. Commercial roofs were first built of wood shingles, metal standing seam, slate and rolled roofing materials. By the early 20th century, new materials such as asphalt and asbestos shingles became widely used along with cement tile and clay tile. Many of Wisconsin’s historic houses and buildings continue to retain their long-lasting historic roofing materials, such as slate and standing seam metal.
Preserve Your Original Chimney
Before central heating and air conditioning systems were introduced, most houses were heated with a fireplace or stove that was vented through a chimney. Houses were built with both an interior and an exterior chimney of brick or stone. The exterior wall chimney was placed along an outside wall to vent the wood and coal smoke from the fireplace. The interior chimney served the same function, but it was designed to retain more heat in the interior of the house. Kitchen stoves sometimes served both heating and cooking functions. Stoves were often vented out the roof through smaller masonry chimneys known as flues.
The original function of a chimney changed in the 20th century, when coal-, oil- and gas-powered furnaces were introduced. In some cases they were used to vent furnaces, while others were used to vent gas logs or wood stoves. Chimneys were often designed to complement the style of the house. Many of Wisconsin’s historic houses display decorative chimneys. Chimneys are an important part of the design and character of many historic houses. If your historic house has an original masonry chimney, you should preserve and repair it as necessary.
To heat a commercial building, a stove was sometimes placed in the middle of the building with a metal flue extending to the roof. Other stoves were placed along the interior wall and attached to flues running up the wall to the roof. On other buildings, a fireplace was built into the walls, especially for upstairs offices or apartments. Most of these early heating systems were replaced by the mid-20th century with a central heating system. The heat was distributed via ducts installed beneath the floor or suspended from the ceiling. Most original flues and chimneys are no longer functional and have been capped or even removed from the roofline.
Chimneys are generally not a prominent feature on a historic commercial building. Most commercial buildings vented heat via a brick flue located along a side or rear wall where it was not very visible. On some commercial buildings, the chimney was treated as a decorative feature with corbelled brickwork, but this type of design is not common. If your historic commercial building still retains a chimney or flue at the roofline, you should consider preserving it as original building feature.
Preserve Your Original Skylights
Your historic commercial building might have a skylight, especially if it has only one or two stories. Skylights were installed on many buildings to provide natural light to the interior of the building. These skylights could be quite large and were built with wood or metal frames and glass panels. Many of these skylights were removed or covered with added materials in the 20th century when modern lighting was introduced. Skylights were also taken out of buildings to meet fire code regulations if they were not built with fire-resistant glass.
If your building has an original skylight, you should try to preserve and maintain as a character-defining feature of your building. In some cases, a new skylight may also be appropriate. For example, if you are renovating upper floor space into offices or apartments, a skylight can be one way to add additional light into the building. However, if you introduce a new skylight, its design should be clearly identifiable as a non-historic element of your building. Your added skylight should not be readily visible from the public right-of-way (sidewalk) on the opposite side of the street, and it should be concealed behind roof parapet walls.
Preserve Your Gutters and Downspouts
Waukesha County. The K-style gutter and downspout is the most common type of water drainage system used on buildings today. Source: WHS - State Historic Preservation Office.
Gutters and downspouts are important utilitarian elements of historic houses and buildings. Gutters and downspouts are important to building maintenance of buildings because they provide proper drainage and prevent water damage to roofs, walls and foundations. You should regularly inspect and maintain your gutters and downspouts to protect your house or building from water damage.
The gutter styles most traditionally used through the mid-20th century were box or built-in gutters. You should preserve and maintain your built-in, box or hidden gutters as needed. If you can find no evidence that your house or building had external gutters, or if the original design of your gutters is unknown, you may consider adding K-style (sometimes called ogee) gutters.
Follow Best Practices
Dane County. Shown here is a new standing seam metal roof. This type of roof can be installed when an original terne metal roof fails. Source: WHS - State Historic Preservation Office.
When you are making repair and maintenance decisions about your historic roof, follow these best practices:
- Retain your historic roof shape and features. Preserve your roof’s original size, shape, pitch and style features (such as cresting and finials). Also preserve your original roof features such as parapets, cornices and chimney flues. Do not introduce new features that would detract from the historic appearance and character of your house or building.
- Place new roof elements where they will not be visible. Make sure that new roof elements, such as skylights, solar panels, decks, balconies and satellite dishes, are not visible from the sidewalk on the opposite side of the street. These elements should also be placed so they do not obscure your roof’s original features.
- Do not remove or alter your original chimney. Preserve your original chimney as an important architectural feature, even if it is no longer functioning. Do not cover your chimney with stucco or other veneers unless they are the same as the original. From a historic preservation standpoint, concrete, slate, unglazed terra cotta and stone caps are considered appropriate.
- Use gentle methods to care for your chimney. If your chimney needs to be cleaned, use gentle cleaning methods. If your chimney needs repointing, use a soft, historic mortar mix that matches your original mortar.
- Rebuild your unstable chimney to match the original as closely as possible. You can rebuild your chimney or add support if it becomes unstable or damaged. The most sensitive treatment would be to disassemble and reassemble your original chimney using the historic brick. Match your repairs to the historic materials, shapes, mortar, material color and brick patterns of your chimney. Physical structural supports may include metal straps or brackets anchored to the roof framing. If your chimney is not character-defining and becomes deteriorated and unstable, you can remove it for safety reasons.
- Install and maintain gutters, downspouts and splash blocks. Retain your existing box or built-in gutters, and keep them in good working order. Repair deteriorated or damaged gutters.
- Install replacement gutters of an appropriate type. If your original gutters are beyond repair, the most appropriate replacement design for hanging gutters is half-round gutters. For buildings dating from or influenced by designs from the 1940s or later, K-style gutters are also appropriate.
- Locate downspouts away from architectural features and on the least public elevation of the building. Visit your roof regularly to check that water is draining properly and downspouts are properly placed. Your downspouts must protect your house or building but not detract from its historic character. Ensure your downspouts drain away from your foundation and does not affect neighboring buildings.
- Keep your original skylight or add an appropriate new skylight. Preserve and maintain your original skylight or use an appropriate design for an added skylight. The most appropriate styles are those that lie flat or flush with the roofline. Place your added skylight in an inconspicuous area where it will not detract from the historic appearance of your building. You can place it on your rear roofline or behind gables, parapets or dormers. Ensure your skylight is not readily visible from the sidewalk from the opposite side of the street.