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RBM[_2_] RBM[_2_] is offline
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Default Installing new bathroom exhaust fan

"djay" wrote in message
I'm installing a Panasonic bathroom exhaust fan - approx fan box size is
12 X 12 inches and it's replacing a POS nutone NOISE maker that has an
opening about 8 X 10. Panasonic has an approx 1" lip on the underside
that would normally screw right to ceiling joists for new construction
(would need to add a 2X4 to make the 12" span instead of the normal 16".
Anyway, I'm in a quandary as to how to correctly install this fan.

It came with "joist spanners" that seem flimsy and possibly difficult to
install. Alternatively it has mounting screw holes in the lip. I want to
just cut out the old fan and expand the hole (I have been up in the attic
and inspected. the existing joist/electrical etc before doing so). One
side of the existing fan is already attached to a ceiling joist. I'd
still use this point as a starting point and expand the drywall hole away
from that existing joist accordingly to fit the new Panisonic box. My
goal is to just cut the hole, install an new spanner joist to snug up to
the other side of the box (would cross between the headers of the two
existing walls) and just use some longer pan head wood screws to screw up
through the "lip" with mounting holes right through the existing drywall
ceiling and into the old existing joist and the newly install joist.

So in my example above after the new hole is cut into the drywall fit the
larger fan, and new joist installed (parallel to the existing joist but
for the other side of the fan hole). I'd push the new fan up through this
hole until the mounting lip rested on the ceiling. I'd put screws in
through this lip, up into the drywall and into the joist above. Then of
course seal in the fan from above and replace the 3" exhaust duct with 4".
Does that sound doable? I guess normally this lip would be between the
ceiling drywall and joist but I can't see a downside to installing it
directly onto the existing drywall.

What do you think?

TIA Djay

Sounds fine as long as there is an adjustment to make up for that half inch
of sheetrock. Otherwise the cover will be hanging down half inch from the