Typical Gambrel Roof Angles

Check overhang to calculate rafter overhang equal to the lower level cut at the full rafter depth.

Typical gambrel roof angles.

The purlin method calculates cuts that bisect the angles at the roof joints. So you have a really steep bottom pitch and a really flat top pitch. Gambrel 2x4 truss measurements defined now we know all the necessary measurements to cut and make our first truss. Check overhang to calculate rafter overhang equal to the lower level cut at the full rafter depth.

There really isn t a standard however i know exactly what you mean about the squatty appearance of your modern gambrel trusses. A gambrel roof is a popular roof style on many contemporary barns and sheds. Draw a semi circle on the graph paper mark a center. Each truss piece will be 3 10 long on the top measurement and the angles cut will be 22 5 degrees off each end.

Calculate gambrel angles with graph paper and a protractor. Since the sum of the three angles in a gambrel roof is 180 degrees the angles you will need are as follows. Determine a pitch for the top slope of the gambrel roof the rise in inches per foot from the midpoint. Besides its unique appearance a gambrel roof also serves to maximize the usable floor space in the attic area.

Gambrel roofs are symmetrical with two slopes on each side of the roof. How to calculate the angle of a gambrel roof truss step 1. The easiest way to get these angle measurements on the ends will be with the use of a speed square. Move slider or directly enter angle to alter sweep angle of lower rafters and change the shape.

Gambrel roof a gambrel or barn style roof is simply a gable roof with a change in slope partway up the roof. 45 degrees where the joists meet up with the top plate or header and 90 where the joists meet in the middle at the ridge board. Move slider or directly enter angle to alter sweep angle of lower rafters and change the shape. Gambrel roof framing geometry calculator metric this gambrel roof confines to a semicircle and starts as the top half of an equal sided octagon.

You will need to make 22 5 degree angle cuts on the rafter joist ends that mate up to the top plate or header.