I am selecting the wall and hit attach top/base then select the roof. Won't attach... any ideas?
Why ont wall attach to roof?
Looks like the Wall misses the Target. If it doesn't, try splitting Wall in two and then use Attach.
...looks like you need more of an overhang over gable side.
...you might want to do your roof sketch like this, using Slope Arrows to define the rake:
