This article investigates community-based disaster responses among informal settlers in a barangay located just outside Metro Manila in the aftermath of Typhoon Ondoy (international code name Ketsana) in 2009. People have embraced some technical measures, such as forcible evacuation, but others have continued customary practices, such as seeking refuge on rooftops where they could get trapped during floods. An important factor in this process has been the credible work of a local people’s organization, which has mediated technical expertise from outside the community. Adaptation of disaster expertise is an ongoing and unpredictable process, shaped by people’s lived experiences and the wider political, economic, and social context.