Overview. WE SEAL DUCTS FROM THE INSIDE OUT! You can see a water leak, but an air leak is invisible. Duct leaks can be difficult and costly to find with ductwork hidden between the walls, floors, and ceilings of any residential home or commercial building. The older, traditional use of mastic (a messy caulk-like substance) or taping of leaks not only is less effective than Aeroseal, but also can be very labor-intensive and expensive and can only be applied to ducts with physical access. Other substances break down over time, but the Aeroseal sealant does not and even has a 10 year warranty to back it up. Do-it-yourselfers might attempt their own fixes, but what about those ducts you or your HVAC specialist can’t see or access? Let Aeroseal handle the entire job and you won’t be tearing up your home or worried about incomplete seals. Aeroseal pinpoints and covers leaks, in roughly an hour, from the inside out with a success rate of up to 98%. Aeroseal is the most effective, affordable, and viable method of sealing air duct leaks on the market.