In this paper we examine the formation of diverse social ties among international migrants to Vancouver, Canada. We look specifically at the influence of involvement in Neighbourhood Houses -- a type of voluntary association -- on facilitating diverse tie formations. Past research has found that membership in different types of associations can lead to more or less network diversity. We build on this research by considering how different types of involvement can lead to either increases or decreases in cross-ethnic or non-immigrant ties among new immigrants. We find that targeted, instrumental types of involvement in Neighbourhood Houses can lead to more diverse immigrant social ties and that general, expressive types of involvement can lead to more homogeneous social ties.