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Monday, February 10, 2020

Roof Styles

The roofer's nightmare
When we think about houses, it goes without saying we're also thinking in terms of "...a roof over our heads. That's unfortunate in that the roof of a house also has a tremendous impact upon the style and era of the house. Otherwise we have little more than walls, doors, and windows. And while each of these may denote a particular architectural style, taken alone, none of them is all that important as to architectural style style. For several years now, I've written as to various housing styles from glass houses to cave houses. All of these have roofs, of course, but this is as closest I've come to a general review of housing styles.

A glossary of roof components.
The onion dome, possibly
the most complex roof
design ever conceived.
A roof serves several purposes other than protecting a house and its occupants from the elements. However, different roof shapes have different pitches, supporting structures, numbers of panels, and even materials, among other features. As such, the roof shape and style will depend on the look and feel desired, costs, needs, preferences, and local weather conditions. Roof shapes differ greatly from region to region. The main factors which influence the shape of roofs are the climate as well as the materials available for roof structure and the outer covering. Roof terminology is also not rigidly defined. Usages vary slightly from region to region, or from one builder or architect to another. But before we can have a serious discourse on roofs, it's vital we understand the nomenclature. We probably all know what a rafter is, but are you familiar with the term, "rake." If not check out the chart above. Although each term is quite specific, some if not most are not words we use in everyday conversation. By the same token, there are some very basic types of roofs (below) which are used in more than one style of housing architecture. Each one is discussed in some detail on down below.

Common roof types
An example of a gable roof.
Gable roof--Gable roofs shed water and snow easily, allow much more ventilation, and can provide additional space in the form of attics or vaulted ceilings. However, gable roofs can be problematic when used in high wind areas, particularly if the frames have inadequate structural support or when there’s too much of an over-hang. In an area that exper-iences high winds, the need for proper braces and roof inspection after a storm becomes quite important. Clay or concrete tiles, asphalt shingles, metal, and cedar shakes are some of the roofing materials you can use for a gabled roof. Though a 40° angle of pitch is recommended for snowy areas, using metal shingles or standing seam could help prevent leaks if the roof features hips and valleys.
The Mansard roof, named for the 17th century
French architect, François Mansart
Mansard roofs have low-pitched portions that are not suitable for areas that receive heavy snowfall. Because of the embellishments and de-tails featured, mansard roofs usually cost more than the more traditional types. How-ever, the added character and space can make up for any extra cost incurred. Since this type of roof is uniquely de-signed, the use of a unique material is bound to make a mansard roof much more special. Metals like zinc and copper are great choices for the roof’s steep portion. While zinc and copper can cost more up front, they are excellent long-term options because they will require minimal maintenance. When installed in a diamond pattern, wood or slate shingles can make mansard roofs stand out. Overlapping composition shingles aren’t, however, a good option. But you can use regular-patterned asphalt shingles on the roof’s steeper portion. Regardless of the material used, the roof’s low-slope part needs to be properly flashed and waterproofed. Types: Mansard roofs come in a variety of shapes, the most common being straight-angle, convex and concave silhouettes.

Frank Lloyd Wright's Winslow House features
a hip roof.

Hip Roof--Hip roofs have four sides with slopes of equal length that come together at the top, forming a ridge. Thanks to the inward slope of these four sides, hip roofs are sturdier, more stable, and can last longer than gable roofs. In fact, hip roofs are an excellent choice for both snowy and high wind regions. The slant allows hip roofs to shed snow and water easily. You can also add a dormer or crow’s nest for extra living space. You can use almost any roofing mat-erial for a hip roof. Options include shingles, metal, and tiles. Hip roof designs are more complex and require more building materials than gable roofs, making them more expensive to build. Along with improper installation, the addition of a dormer could lead to the formation of water leaks in the valleys and several other issues, hence the importance of proper construction and maintenance. As mentioned before, this roof is very similar to the bonnet roof. The main difference is that the four sides of the roof meet at a ridge or a flat spot, instead of coming to a point at the top. This enhances the practicality of the roof type.

A pyramid roof.
Pyramid roof--is a variation of the hip roof except that rather than a ridge down the length of the roof, the slope origin-ates from a single high point in the center, sloping in all four directions. Pyramid roofs were quite popular in the early de-cades of the 20th century but are seldom used today.
The saltbox roof, named for its resemblance to
the colonial kitchen storage container for salt.

The Saltbox is sometimes called a house style, a house shape, or a type of roof. It's a modification of a gabled roof. Rarely is the gable area on the front, street-facing façade of a saltbox. A saltbox roof is distinctive and characterized by an overly long and ex-tended roof in the back of the house—often on the north side to protect interiors from harsh New England winter weather. The shape of the roof is said to mimic the slant-lid storage box that colonists used for salt, a common min-eral used to preserve food in Colonial New England. The house shown here, the Daggett Farmhouse, was built in Connecticut in the 1760s. It is now on display at Greenfield Village at The Henry Ford in Dearborn, Michigan.

The Dutch colonial housing style often features
aa gambrel roof.
Gambrel Roof--Although it is almost the same as the mansard since both have two slopes, the gambrel or barn roof features two sides instead of four. Same as the mansard, the gambrel roof’s lower sec-tion has a steep, almost ver-tical slope and a much lower upper slope. Although the name is synonymous with Dutch Colonial and Georgian style houses, gambrels are often used on log cabins, farm houses, and barns. The gambrel is not only easy to frame out but offers extra living space as well. This design involves fewer materials and is simple to construct, meaning significantly lower costs up front. The gambrel uses two roof beams and gusset joints. In addition to being one of the greatest roof shapes for storage buildings and outdoor sheds, gambrel roofs have a shape that provides more room for storage without occupying more space than any of the other designs. However, since this open style is susceptible to extreme pressure, it's not recommended for heavy snowfall and high wind areas. When installed in areas with extreme weather, reinforced trusses should be used to support the upper pitch. This type of roof is very similar to the Mansard Roof. This Dutch-inspired type of roof is made up of four slopes, two on each side of the home. The lower slope is a much steeper vertical style than the upper slope, which might or might not be visible from below

Flat roofs lend themselves to contemporary
modern housing styles
Flat Roof--As the name suggests, the flat roof looks completely flat to the naked eye. They do, however, have a slight pitch, one that enables water run-off and drainage. Although flat roofs are mostly used for commercial buildings, they are also great for resid-ential houses. This is one of the easiest types of roof to identify because it is very common–and flat, as its name implies. Flat roofs are easier to construct than any other roof type. They are safer to stand on, and they are generally more accessible for maintenance and repairs. The main drawback to this type of roof is that it does require more maintenance than other types, largely because the lack of slope can tend to accumulate debris. Other than the fact that they can work well in both low and high rainfall areas, flat roofs offer an unmatched amount of outdoor living space. While flat rooftops can be used as a site for partially enclosed penthouse rooms, gardens, or patios, the design also allows the installation of heating and cooling units as well as PV solar panels. Compared to pitched roof designs, flat roofs require fewer building materials and are easier to construct, both of which help lower costs. Though this type costs less to install, they can be more expensive than pitched roofs in the long run because of ongoing maintenance, repair, and replacement costs. Also, the low pitch makes them more susceptible to leaks, which means flat roofs might not be an excellent choice for high rainfall or snowfall areas. Materials that are continuous and do not involve any seams are the best option, especially since flat roofs must be waterproof. Tar and gravel, metal sheets, PVC, roll roofing, rubber membrane, and TPO are the most common materials.

The bonnet roof often involves a house with a
wraparound porch.
A bonnet roof-- features a double slope on all four of its sides. The lower slope is less steep and more angular than the upper slope and extends over an open-sided raised porch. The design of the roof of-ers great shade and pro-tection. The roof’s design is an opposite to the standard man-sard roof due to its upper slope being far steeper than the bottom slope. Bonnet roofs are also known as a kicked-eaves roof. Kicked eaves are a roof enhancement that gives the home a visor effect. Modified gable roof, modified hip roof and a belcote roof are also common names for a bonnet roof. Bonnet roofs are generally seen on homes that have porches around the perimeter of the building.

A contemporary modern style house often
utilizes a shed roof similar to this one.
Shed Roof--Think of a shed roof as a flat roof at a steeper slope. You can also think of it as one half of a traditional gable roof. Whereas a hip roof and other popular roof types have at least two sides, the shed roof has a single slope that can vary in steepness depending on the design. This style was once used mainly on sheds, but it's becoming more popular on residential homes. Sometimes, the entire roof is a shed-style roof. On other homes, only a section of the structure uses a shed roof. You might use a shed roof on a new addition to your home even though the rest of the house has a hip roof or another design, for example. It's a simple and inexpensive way to roof the newer section. Since the shed roof has just one flat surface, it's a very simple design that makes it easy to build. Your contractor doesn't have to worry about various surfaces meeting, multiple ridges or lots of valleys that make the job more challenging. That means your contractor can build your roof much faster than many other roof styles, and you have a clean, simple look when it's done. The simplicity of the shed roof design also makes it more cost effective. This style uses fewer materials, which cuts down on that part of the cost. It's easy for roofers to build, so they can complete the job faster for less labor time, and there aren't any complex parts of the job to make the price skyrocket. Roofs with multiple valleys introduce more places for leaks to happen and more potential places for pooling water. The shed roof eliminates those additional seams and pooling spots to better shed the water and keep the roof safe from water damage.

The jerkinhead roof style of the Harriet Beecher
Stowe House, Hartford, Connecticut.
Jerkinhead roof--The Harriet Beecher Stowe House in Hart-ford, Connecticut has a hipped gable or jerkinhead. A jerk-inhead roof has a hipped ga-ble. Instead of rising to a point, the gable is clipped short and appears to turn downwards. The technique creates a less-soaring, more humble effect on residential architecture. A jerkinhead roof may also be called a Jerkin Head Roof, a Half-hipped Roof, a Clipped Gable, or even a Jerkinhead Gable. Jerkinhead roofs are sometimes found on American bungalows and cottages, small American houses from the 1920s and 1930s, and assorted Victorian house styles.

Factory made skeletal roof support designs. Notice they all rely heavily
upon the triangle for their strength.
There are any number of additional roof styles to numerous to mention. Some are derived from the ones depicted above, or are combination of the most common styles. Below you'll fine images which describe their various features more accurately than I can with mere words. Except for doors, roofs are the most important element in the house. The roof is the major determinant of a house's style, not just as shelter from the elements.


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