We televised some underground duct work for a HVAC company who had a customer having problems with the ducts blowing sand out of the ducts up into the house. We were able to come in clean up the dirt, sand, and debris in the lines apply our spin cast mortar system to give strength back to the weak metal elbows and connections. Finally after the prep work we came in and sealed the underground ducts with our duct armor product leaving a nice clean airflow and breathing environment.