Gambrel Roof Components

Roof Components

• There are two components to each side of a gambrel roof: the upper slope and the lower slope. The lower slope is steep, so that snow will slide off instead of accumulate. The upper slope is not as steep, to allow for greater space underneath the roof. This is why the gambrel roof has always been a popular choice for barns and houses where space is at a premium. It allows for much greater storage or living space without the problems of flat roofs.

Examples

• English gambrel roofs have an upper slope of about 25 degrees and a lower slope of about 45 degrees, with the size of the slopes being equal. Dutch gambrel roofs have a smaller upper slope, with a pitch of about 22 degrees. The larger lower slope has a steep pitch of approximately 60 degrees.

Construction Components

• Each section of a gambrel roof is made out of a series of boards called trusses that sit at an angle to the vertical. They are bound together by horizontal braces running along the side. Opposite sides are held together by other horizontal joists or rafters. Other braces are sometimes required between the sides of the roof and the floor for support. Instead of these braces, some gambrel roofs are supported by upper story walls.

Design Components

• There are many components to the design of a gambrel roof. To make a usable design, you need to know the upper and lower slopes, the width of the upper section, the width of the lower section, the heights of the upper and lower sections and the size of the lumber available. Many of these factors depend on other factors, such as the amount of floor space you need available, the type of bracing you will use, the amount of snow that falls over the course of the winter in your area, and the strength of the winds that your roof will likely sustain. Proper design is a complicated procedure that should be left to experts. If you lack training and experience, hire an architect or purchase professional pre-drawn plans.