A gambrel roof is a ridged roof that has two slopes on each side--a steeper one above, a shallower one. It received its name because its shape is said to resemble the hind leg of a horse, which was once referred to as a "gambrel." Gambrel roofs are common to certain kinds of houses and barns, particular those built in the Dutch colonial style prominent in the Hudson River Valley. These roofs have several advantages.
Gambrel roofs were originally popular because the steep lower slope allowed for maximum head space, giving homes with a full-size loft space to be used as an attic or guest bedroom. The addition of dormer windows, common to gambrel roofs, adds even more space. Also, the trusses that support a gambrel roof allow for more storage space between them than traditional rafters.
Handle Wind Loads
Traditionally, gambrels were not able to be placed in areas that experienced significant wind or snowfall (or else snow would have to be cleared) because the roof was not particularly strong. However, now, due to mote modern materials, gambrels can withstand very strong wind loads.
Gambrel roofs have a complex, but visually pleasant symmetry that is lacking in certain other types of roofs. The hip roof, with its four long, shallow slopes, and the gabled roof offer little in the way of visual interest, while the hipped gable roof and the mansard roof are often too busy. The gambrel roof, with its two crooked lines, offers a statement that is simple, but elegant.
The limited framing required to support a gambrel roof takes up little space, leaving more options for the floor plan. In addition, the series of trusses that hold up the sides of a gambrel place little weight on the ceiling, leaving the architect greater options when designing the house.
Gambrels have a unmistakeably classic look, one that dates from colonial America. Modern homes that add a gambrel are placing their homes within a distinctly American tradition. The style is associated not just with the Dutch colonial style, but with the Georgian style, which was common to early American architecture. For example, the famed Thomas Riggs house in Gloucester, Massachusetts, dates from 1661 and features a gambrel roof.
Simple to Frame
Gambrels remains relatively simple to frame and construct. Traditionally, a gambrel roof makes use of two rafter systems attached by a horizontal nailer at the middle of roof, but more modern methods allow it to employ gusset joints at midrafter, which is even simpler.