In a previous article, the author proves that the value of the root number
varies in a family of elliptic curves indexed by one parameter $t$ running
through $\mathbb{Q}$. However, a well-known example of Washington has root
number $-1$ for every fiber when $t$ runs through $\mathbb{Z}$. Such examples
are rare since, as proven in this paper, the root number of the integer fibers
varies for a large class of families of elliptic curves. Our results depends on
the squarefree conjecture and Chowla's conjecture, and are unconditional in
many cases.