On 7/25/2020 1:35 PM, trader_4 wrote:
On Saturday, July 25, 2020 at 1:40:17 PM UTC-4, dpb wrote:
....

One _PRESUMES(!!!)_ the ply is simply fastened to the underside of the
porch floor joists and is there simply as the backing for the ceiling
formerly there.

Any idea if there's any insulation there or not?

That's a good point, now that we know that it's under a porch,
which presumably isn't heated. With no insulation if it's a cold
climate condensation from the bathroom shower will be a problem.
And it will be wasted heat going out too. Sounds like that should
be investigated and if there is no insulation, then that's
reason to remove the plywood that's there and put insulation in.
Could possibly do a drop ceiling after that. Me, I'd just do drywall,
but for whatever reason she doesn't want that. It's odd that someone
put plywood up first, then drywall. Usually when you see stuff that
doesn't make sense, there is more that was done that's wrong too.
I wonder what condition this was all in before starting the renovation?

....

None of this will be anything at all approximating "normal" building to
Code; that's pretty apparent in that they put a bath under the porch in
a basement that's barely 7-ft, if that.

If you look at the picture showing the shower head, there's only a
couple inches above it to the ceiling; no way to put in any dropped ceiling.

Undoubtedly the ply was put in to separate off the outside porch
solidly; there's no telling whether there's a solid rim joist on it or
not, even, for sure. One would hope there is, but when the owner says
the house is of so little value the property when and if sold would be
for land value only; the house would be undoubtedly be razed, who could
even begin to guess just what it consists of?

Concrete board would be ok, but in this location drywall is just not
going to cut it for long, even if do manage to ventilate it some and
stop condensation besides the inside humidity. Those would help prolong
the inevetable, but it's still agonna' happen in such a confined area.

--