Development studies highlight the importance of scaling good practices and their replicability and transferability to face global warming. But what happens when practices originate in informal urban contexts? Should they be replicated, amplified and formalized? We explore the opportunities and contradictions that emerge in scaling disaster risk reduction in informal settings. For four years, we documented 24 local initiatives and the work of leaders in Latin America. Results show that impact depends on intermediaries, trust, dialogue and a delicate balance between conflicting objectives and different levels of involvement by externals. To succeed, initiatives must address "the problem of doing more."