The research and development centre at Chandivali has converted an old studio as their office. The structure has pre-coated G.I. roof with Aluminium composite panel cladding façade. BASF was facing severe leakage problem from the junction of the pre-coated roof and the ACP cladding. Attempts made by different agencies to find out the source of leakage, went futile for more than two monsoons. We identified the source of problem and solved it with self adhesive membrane.