Most gabled roofs have eaves so you probably need to create them for your building.
How to make a cross gable roof in sketch up.
Push pull back your triangular gable.
Use the line tool to draw a vertical edge from the midpoint of your roof to the angled guide you created in step 2.
This video accompanies google sketchup for dummies by aidan chopra.
Gable roof exerise sketchup 8 avi.
1 create a roof overhang.
Easily creates roofs with various parameters in sketchup plugin name.
Draw two edges from the top of your vertical line to the corners of your roof.
Follow these steps to build a gabled roof.