What is a Gable Roof?

A gable roof has two upward sloping sides that meet in middle at the ridge. To be a true gable, both sides must slope at the same angle. Viewed from the end, the shape of a gable roof appears as a symmetrical triangle. Gable roofs are the most common style of roof in the United States. They are popular in areas that receive substantial snowfall.

History

Thought to originate from the ancient practice of leaning sticks or logs at an angle to form a triangular hut, the gable roof has its roots firmly entrenched in history. During the 14th century, gable roofs became a popular sight in European cities, incorporated as dormers on elaborate chateaus and used by peasants for modest rural huts. Today, the low-pitch gable roof is a cost-effective method seen in ranch-style homes.

Types

There are two main types of gables and both form symmetrical triangles. The traditional gable has smooth straight rooflines and is very common. The second type is a crow-step gable and while it forms a triangle, the line of the roof itself features steps instead of a smooth slope. Crow-step gable roofs are traditional on European-style and Southwestern-style homes.

Geography

Gable roof pitches are generally steeper in cold climates where snowfall is substantial. As the pitch of the gable rises, so does the cost of construction. Found in mountainous locations, many feature metal roofing, encouraging the snow to slide off easily. Gable roofs with gentle pitches are favorable when price is a factor and the climate is mild.

Considerations

High-pitch gable roofs are more likely to suffer damage from high winds due to the resistance factor that increases as the slope of the roof rises. In areas prone to hurricanes or tornadoes, the end of a gable roof should be reinforced with extra structural support. Before constructing a gable roof in such a location, the homeowner should contact the local building authority for recommendations or code restrictions.

Misconceptions

Some triangular roofs are not gables. In New England, a popular roof style, first seen during the Colonial period, features both sides of the roof sloping upwards to meet in the middle, yet the roof is not a true gable because the angle of slope for each side is different. These are saltbox roofs and they are also found in solar-powered homes where the South-facing angle holds solar panels.

Potential

An architect or builder has the potential to combine numerous gables within one roof. The benefits of this type of gable roof are mainly aesthetic, as cross-gable roof construction is more expensive with the price increasing with every added gable. There is also an increased potential for roof leaks, since there are more valleys connecting the adjoining roof lines. The valleys on a roof are at greater risk of leaking, due to frequent improper flashing, incorrect nail placement and the bending of the shingles to fit the valley. An experienced roofer should install the shingles on a cross-gable roof.

Resources

• Use an online roof calculator to determine the pitch of a gable roof.