Through an examination of building practices in the U.S. and Mexico, my collaborator, Nichola Lowe (UNC-Chapel Hill), and I ask how migrants in the construction industry move tacit knowledge across borders, how they reinterpret it in new contexts, and how they use it to challenge and amend the political structures they encounter. We find that understandings of material processes are deeply political, with implications for labor politics, industrial policy, and urban planning and design. Migrant workers use processes of tacit skill transformation to cultivate new sources of political power. In ways that were both subversive and strategic, they use the meanings they develop through their reinterpretation of materials and building structures to improve working conditions and production processes, to repurpose industry institutions, and to develop new forms of local and transnational solidarity.