I have a heating duct that empties up into the room at the perimeter of the
house where it is cantilevered 18" over the 1st floor.
The duct ending is run between the two joists and is missing insulation.
Can anyone think of a way to cut from inside the register opening to put
insulation into the cavity? There isn't much room for a drill, even a
The only other option is to drill/cut from underneath outside. But that
would involve removing the vinyl soffits, etc.
Any ideas would be appreciated.
How do you know it is missing insulation if you can't get at it?
The metal is probably fastened to the floor wiht a few roofing nails
if it's installed the way I have seen most. Getting it up and out
will depend on the dimensions of the register verses the size ofthe
flex that is attached to it. If you can manage to pull it out through
the hole you coul stuff in some insulation and then put it back.
Otehrwise you are ging to have ot remove something.
Is the ceiling finished in the 1st floor room under the cantilever
section? 18" isn't very far to reach and stuff insulation if you can
access the joist cavity from the 1st floor room.
If the register is fed from flexible duct you might be able to move it
back and access the cavity from above, but flexible duct is also usually
Otherwise, removing the soffit under that area is going to be your best
That sounds like the best thing to do, that foam goes everywhere, the
only question is whether to use regular expanding foam, or one of the
variants that do not expand as much.
I did not mention that I have hardwood floors. So I can't really drill down
without having to patch the wood floors, which I'd prefer to avoid.
But that is definitely something I should consdier. I know I can buy
face-grain oak plugs that should match the grain.
Not endorsing the spray-foam idea without seeing it, but is this
register flush to floor, or set into the baseboard? Either way, there
is usually enough room under the removed register to drill a small
hole or two, and have the register cover it. It doesn't have to be in
the actual floor- it could be at a 45 degree angle just inside the
opening. If the foam doesn't seal it, a dab of aluminum tape will. The
hoses on those spray cans are pretty tiny. If you go that route, I'd
use the low-expansion stuff, lest you collapse the duct, or blow out
the soffit, or the ceiling of the room below. But do the math first- a
joist bay is 14.5 inches wide x 7.5 (or 9.5 or 11.5) inches tall, by
however long the overhang is. Swag a number for how much space the
duct takes up, and make sure you get enough foam, and that the hose is
long enough to reach deep in there.
Having said all that, going in through the soffit is the proper
approach. If it is vinyl soffit, and there is no old wood soffit above
it, they are usually pretty much snap-in-place panels, held at most
with a self-tapping screw in a blind spot. Get on a stepladder, and
push up on it- it should be self-evident how it goes together. Is the
floor cold over the entire overhang? You may need insulation bats all
the way along that run, not just where the duct is.
Stuff like this, I recommend doing it right and getting it over with.
It won't be as bad as you think.
aem sends, on Google until 29th...
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