Building a gambrel truss may seem to be a complicated undertaking, but there are some very simple design plans for such projects. A truss is a structure that is constructed with various triangles. The purpose of the triangular structure is to improve strength and durability of the final project. Because of the triangular pattern at the foundation, trusses often have gambrel roofs. A gambrel
. roof is one that has two slopes on either side of the structure. The lower slope of a gambrel truss structure is always steeper that the slope above it. You can find more information here: http://www.motherearthnews.com/Do-It-Yourself/1977-03-01/Design-Construct-Gambrel-Roof.aspx