I would like to design my roof slopes/pitches in fractions of 12, i.e. 1/4:12; 2:12; 6:12. Is there any way to do this? My industry, Pre-engineered metal buildings in the United States is completely set up to use roof slopes/pitches that are set up this way and I would like to stay similar to that system. I was hoping for a ruby script/extension that does this automatically.