Calculation Tips for a Gambrel Roof

A gambrel roof on a barn.

A gambrel roof design is a very distinctive attribute of barns, sheds, and outbuildings. While the gambrel roof design is used for homes as well, it is mostly found in large barns and garages because of its strength over a large area. If you are thinking of a building project that involves a gambrel roof design, here are a few tips to help you calculate the angles.

Four Angles Needed

With the gambrel roof design, there are four angles that are used to make up a total of 180 degrees. Depending on the size of the roof, and the pitch of the roof, these angles will change. You want to try and use angles that are as close to 45 as you can get for both ease of construction and good strength.

Width vs. Height

A good rule to follow with a gambrel roof design is that it should be twice as wide as it is high. This will give not only asymmetrical appearance but also balance out the load of the building over a much more stable area.

Lower Pitches

Typically a gambrel roof does not have an extreme pitch to it. This is because when you have too much of a pitch you will need to go very high with the roof. Keeping the roof pitch low to a 12/12 pitch will give you much easier angles to work with.