How can I fix leaking ductwork?

Fixing leaking residential heating and cooling ductwork requires a systematic approach to locate gaps and seal them using approved commercial materials or advanced automated processes. First, inspect all accessible duct runs in your basement, crawlspace, or open attic to identify loose joints, disconnected boots, and torn flexible duct sections. Second, clean dust and debris off the metal or flexible surfaces thoroughly. Third, apply water-based fiber-reinforced duct mastic paste generously over all seams and joints, reinforcing them with UL-181 approved aluminum foil mastic tape rather than cheap fabric duct tape. Fourth, for inaccessible ductwork hidden behind walls, hire a professional contractor to perform aerosol sealant injection. You can troubleshoot by feeling for air drafts. You can verify that your repair was successful when diagnostic pressure testing confirms duct leakage has been completely eliminated.