Gambrel Roof Slope

Move slider or directly enter angle to alter sweep angle of lower rafters and change the shape.

Gambrel roof slope.

The difference between the two is that the gambrel only has two sides while the mansard has four. In other words if you start with a say 14 12 bottom pitch your top pitch should be 7 12 or greater. Anything less than this will ultimately result in a roof that leaks if you plan on putting shingles on it. A gambrel style is often called a barn roof.

It also shows you various heights along the interior of the sloped gambrel ceiling ie. Check overhang to calculate rafter overhang equal to the lower level cut at the full rafter depth. The shallower the top pitch the more squatty it will look. 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.

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. Compare with bell roof. 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.

Gambrel roof framing geometry calculator inch this gambrel roof fits in a semicircle and starts as the top half of an equal sided octagon. A roof similar to a mansard but sloped in one direction rather than both. A gambrel or gambrel roof is a usually symmetrical two sided roof with two slopes on each side. A gambrel or a barn roof is much like mansard in a sense that it has two different slopes.

This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. The rule of thumb that i use when designing a gambrel is that the top pitch should be no less than half the pitch of the bottom. Maximum height in the center height at the pitch break how far in from the side wall a six foot height occurs etc. Similar to mansard the lower side of the gambrel roof has an almost vertical steep slope while the upper slope is much lower.

A gable roof has only two rafter or truss chord angles a top cut at the peak and a bottom cut at the walls. 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. Well let s face it it s a very attractive roof design but there are practical considerations as well. If at all possible it looks the best at exactly half.