If you're planning on building a gable roof, it wouldn't be a bad idea to pick up a couple of books or read a few articles, especially if you don't have any idea how to build one. Let me see if I can help you, by providing five tips for easier gable roof framing.
1. One of the simplest types of gable roofs that you can build today would be an engineered type truss roof system. Contact a roof truss manufacturer in your area for more information. This type of gable roof system is very easy for most do-it-yourselfers to assemble.
2. Always cut two roof rafters first, before cutting anymore. It's always a good idea to double check your measurements and this can be done, simply by temporarily installing one on each side of the roof, to make sure that they are the correct length.
3. Make sure that you lay your roof rafters out according to the specifications on the plans. If the roof rafters call out for 16 inch on center rafter layout, make sure that your rafters are exactly 16 inches on center, or you will find out later that you're going to have problems with your plywood roof sheeting.
4. If your gable roof framing is going to be steeper than a 5 and 12 roof pitch or more than 22° roof slope, you could find yourself having difficulties walking on the roof. If this is the case, install a couple of long temporary 2 x 4's about 48 inches apart, to give you something to grip onto, in case you start to slip.
5. When you're installing the roof sheeting, make sure that there isn't any sawdust on top of the roof sheeting, because this makes the plywood roof sheeting extremely slippery. I use an electric lawn or garden blower to regularly clean these areas off, to avoid slipping off the roof.
If one of these roof tips were helpful to you, it was worth reading the article.