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Community and Q&A

Mastic inside of supply plenum?

56man1000 | Posted in Green Products and Materials on

I had a New Goodman hvac split system installed. That I bought online. Supply plenum on top of air handler was coated with DP 1030 mastic on outside and… THE WHOLE INSIDE.  Says on container: Water Based, Non-Toxic, No Voc’s, but I also heard that mastic should not of been put in the air stream. I have extreme chemical sensitivity’s so have to be very careful about these things. And I’m concerned whether should leave it or have it replaced by another a/c contractor. This SO CALLED CONTRACTOR, was from Craig’s list. Took money and run kind of guy. I am not using it at this point until I find out if it is safe. The system seems to be running fine quiet & cooling great.  Just concerned about the mastic issue.  Thank you, Dale

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  1. Expert Member
    BILL WICHERS | | #1

    I don't think this is a safety issue, but I've never seen it done before. Mastic is typically applied on the outside of the ductwork only, and usually only at seams -- not over the entirety of the duct.


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