Hope someone can give me some guidance on this one!
I removed the dropped ceiling in part of the downstairs of the 1981
house we just bought in Austin, Tx, and am having to reroute all of
the ducts in the first floor to get them up in the joists. That's not
a problem - I'm just replacing the old gray flex-pipe with new pipe of
the same diameter.
But upon pulling out the old stuff, I saw that ALL of the ductwork -
from the 12" cold air return to the two 10" main feeders from the
attic unit to the duct board distribution triangles and ducts to the
individual vents, had a think black powdery crust lining at least the
bottom surfaces of the ducts and duct board register boxes (boots?).
The crust is dry, dark gray/black, and will flake off if you scrape
it. It's kinda furry, but it's dry. We did 2 mold tests, and they
were not out of the ordinary for this kind of house. It's kinda like
just 30 years of dust and dirt accumulating in the ducts, and crusting
up. Is this normal?
Anyway, to be on the safe side of getting as much crud out of the
system as possible, I decided to replace the 12" cold air return flex
pipe and two 10" main supply ducts from the attic, as well as the duct
board distribution triangles and smaller ducts that I had to change
My question is: when I pull the big ducts off their collars on the
unit in the attic, am I going to find a big, gross mess of crust in
the boxes that connect to the unit in the attic? Will I need to
replace those as well? What about the rest of the unit itself?! And
what is this junk anyway?! I can't take on replacing the attic unit
now - just no time or money left. And it works fine. Am I going to
cause bigger problems by disturbing what is up there?
The thing is, if I'm going to replace these ducts, I have to now
because I have the 1st floor ceilings and the chase all opened up.
After I close them up, I'll never be able to replace them. Is it okay
to put the new ducts on the old plenum and intake at the unit in the
attic, then maybe replace that some other time?
Should I just close it all up and pretend I never opened it and saw
the insides in the first place?
I appreciate any help!