Originally Posted by Hoff77
Please help! I am building a 12x12 shed with a gambrel roof. I need to figure out how to calclulate the length and angles for the gambrel roof. I want it to be 3 ft high in the middle. Can anyone let me know how to calculate the measurements and angles?
I don't know about the 3 ft in the middle but I found the easy way is to get a level concrete floor and lay out the 12 ft square and pop a chalk line this will make a square now come over on the bottom and make a mark at 3 ft 6 ft and 9 ft at the 3 ft mark and the 9 ft mark make a 45 degree angle toward the outside them pop a chalk line all the way through the roof line this will give you the lower roof rafter then to get the top rafter get the height in the center them pop a line to intersection of the top of the 3 ft and the 9 ft line this will give you the top the angles should be 30 degree and 60 degree