Gambrel Roof Slope

The difference between the two is that the gambrel only has two sides while the mansard has four.

Gambrel roof slope.

If at all possible it looks the best at exactly half. A gambrel style is often called a barn roof. A gambrel or gambrel roof is a usually symmetrical two sided roof with two slopes on each side. Its double or sometimes triple slopes on each side of a peak provide more space inside the roof which is attractive to homeowners too.

A gambrel or barn style roof is simply a gable roof with a change in slope partway up the roof. This means that for every 12 horizontal run you must have at least 3 of rise. Move slider or directly enter angle to alter sweep angle of lower rafters and change the shape. It also shows you various heights along the interior of the sloped gambrel ceiling ie.

A roof with the shallow slope below the steeper slope at the eaves. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. Similar to mansard the lower side of the gambrel roof has an almost vertical steep slope while the upper slope is much lower. Well let s face it it s a very attractive roof design but there are practical considerations as well.

Gambrel roof framing geometry calculator inch this gambrel roof fits in a semicircle and starts as the top half of an equal sided octagon. Maximum height in the center height at the pitch break how far in from the side wall a six foot height occurs etc. A gambrel or a barn roof is much like mansard in a sense that it has two different slopes. Anything less than this will ultimately result in a roof that leaks if you plan on putting shingles on it.

Check overhang to calculate rafter overhang equal to the lower level cut at the full rafter depth. A roof similar to a mansard but sloped in one direction rather than both. The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7. Besides its unique appearance a gambrel roof also serves to maximize the usable floor space in the attic area.

The usual architectural term in eighteenth century england and north america was dutch roof the upper slope is positioned at a shallow angle while the lower slope is steep. When you are designing your shed roof whether it be a gambrel gable or saltbox you should never have any roof pitch less than a 3 12. Compare with bell roof. In other words if you start with a say 14 12 bottom pitch your top pitch should be 7 12 or greater.