Typical Gambrel Roof Pitch

Gambrel roof framing geometry calculator inch this gambrel roof fits in a semicircle and starts as the top half of an equal sided octagon.

Typical gambrel roof pitch.

Lower slopes don t handle wind driven rain as well. A gambrel or barn style roof is simply a gable roof with a change in slope partway up the roof. To calculate a gambrel roof select gambrel roof from the roof type dropdown list or click on the appropriate toolbar button to calculate a. Determine a pitch for the top slope of the gambrel roof the rise in inches per foot from the midpoint connection to the peak.

Check overhang to calculate rafter overhang equal to the lower level cut at the full rafter depth. Anything less than this will ultimately result in a roof that leaks if you plan on putting shingles on it. Thus a 4 12 pitch would be a 33 slope. A 4 12 pitch is around 18 5 degrees but not exactly.

Most of your pre made trusses that are designed as a gambrel consist of roughly a 20 12 bottom pitch and a 4 12 top pitch. Steeper slopes increase the sail effect that makes them susceptible to wind. To see how pitch impacts the look of a garage and changes cost click the design center button on our pole barn kits page. 7 12 or a rise of 7 inches per foot is a common top gambrel pitch.

Move slider or directly enter angle to alter sweep angle of lower rafters and change the shape. A 30 degree roof slope 7 12 pitch is the right pitch to aerodynamically handle high wind. Roof pitch refers to the amount of rise a roof has compared to the horizontal measurement of the roof called the run. Besides its unique appearance a gambrel roof also serves to maximize the usable floor space in the attic area.

This means that for every 12 horizontal run you must have at least 3 of rise. There really isn t a standard however i know exactly what you mean about the squatty appearance of your modern gambrel trusses. You can also divide the rise over run multiply by 100 and get a percentage. Make that pitch 12 7 a drop of 7 inches per foot from the connection to the wall.

So you have a really steep bottom pitch and a really flat top pitch.