"LJ" wrote in message
...
Discovered one vent (so far) where the "box" inside the wall was
simple cardboard. The furnace is probably 12 years old, ductwork is
probably older than that. The duct itselfs comes up about 2" short of
actually contacting the cardboard, meaning there are gaps where I can
see directly into the basement.

Was this some sort of normal hack years ago, or some nimrod's idea of
a cheap shortcut? It certainly seems dangerous to use paper products
around a forced-air gas furnace.

Is it feasible for an average handyperson to construct a new "box"
with duct board or sheet metal & mastic? I have tin snips & other
basic tools, although no way to make decent bends if the sheet metal
is too thick. Duct board is new to me. I've worked with drywall and
greenboard, however.

Thanks.

This had to be a nimrod. No HVAC person or even a self respecting
handy-person would do it that way. Air in the ducts never gets more than
125 degrees so I don't think you have a fire hazard on your hands.

The boxes as you call them are normally sold premade. They are called
register boots. If you are coming off of a round pipe, you may be able to
find what you need at the borg. If you are coming off other duct work you
may need to buy a couple of pieces to make it work.

No matter how abnormal it is tin, snips screws and patience will allow you
to connect it. You might need a hand break or seam bender to bend some of
the metal.

Colbyt