# Under ground duct work



## JohnH1

I have a customer we cleaned the duct work due to a huge ammount of dust in the home. 
The video inspection after showed the duct system is developing pin holes and sand is entering the system. 
Anyone know of a sealing system that can be used similar to Areoseal?
I have a pipe and sewer relining company calling me back tomorrow to discuss relining the duct similar to relining water piping. Anyone ever try something like this?:001_unsure:


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## JJDH

I dont have an answer directly, we often will abandon the underground ducts and install things in the attic, or convert to upflow and have a central return. That is the best bet.Relining may or may not work and will change the dynamic of the system.


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## JohnH1

Two days in a row with the different jobs. Both under the slap duct work. We had to put the neg air machine outside on both jobs and ran the suction hose inside. So much sand, dust and dirt the filter system couldent handel it. it would plug up instantly. Pulled the filters and dusted the back yards up.
I did find a robatic system that can spray mastic inside the duct system to seal the holes ( at least temporally untill it rotts further) Cool tool but big $$. The only problem is that it wont fit 6" round pipe. There has to be another way.


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## JohnH1

Here is a pic of the duct under the slab. I am still wating on The guy that makes the mastic spray tool to call me back about Just selling me the spray tool and I may be able to mount it to my camera wheels. I think that may fit. Here is a link to a video of the tool. Let me know if you guys think this may work. http://www.lloydssystems.com/downloads/hardcast.wmv


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## JohnH1

Wow I did not expect the cost of the sprayer. To customize one that could fit in a 6"round duct and be able to make it through a 90deg elbow $8,000 to $9,000 Then to include the robot/car $10,000. I guess I am quoting new overhead duct work.


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