After you finish the Silo series, if you're wishing for more, there are some short stories in the same universe in an anthology Hugh Howey edited:

https://en.m.wikipedia.org/wiki/The_Apocalypse_Triptych

I generally prefer long-form fiction, but very much enjoyed most of the stories in the Triptych books, and they led me to other, similar authors whose work I also enjoy.