There used to be a lot of rats in my attic, at least from time to time
over the years. I'd set out rat traps to control them and they've been
eliminated, at least for the time being (none for over 6 months).
Denying them entry will have to wait for some other stuff to happen here
(foundation work, etc.) but the traps have made my house discouraging to
them, and they aren't willing to try anymore.

My roof was completely replaced in November and I spent a few weeks
completely cleaning out the attic. After the tearoff, the mess up there
was huge and daunting, but I buckled down and cleaned the attic as never
before, ultimately vacuuming out every rat turd I could find, as well as
removing all the debris from the roof job.

Yesterday, there was an unfortunate accident. A workman was trying to
clear a bath tub drain clog with a waterhose-powered device that forces
water down the drain in hopes of clearing the drain. The water backed up
the roof vent, which is not uncommon. Unfortunately, the vent had a hole
the size of a dime in the attic and much water (several gallons,
evidently) sprayed over an area of about 100 square feet, most of it
dripping (or pouring) through the ceiling. Luckily, summer starts
tomorrow and the weather here is warm and dry, and with a big fan in the
attic, the lath and plaster ceiling/attic-floor barrier between the
upstairs and the attic appears almost dry already, some 15 hours after
the "accident." My problem at the moment is the smell, and it's filling
the house. The water on the lath and plaster has apparently reactivated
impregnated rat urine. I figured that out this morning after enduring
the smell all night.

I figure the smell will subside as the ceiling truly dries, but am
fearful it will not. Can I get any hints or suggestions? Maybe an
alcohol-thinned coating of shellac brushed on the lath? That's all I can
think of but there may be better ways to deal with it. Or will that
smell go away when things really dry out? Maybe it never really was not
there, but it was just subtle enough that I learned to ignore it.
There's going to be a mini heat wave here and I think the ceiling will
be dry by the weekend. Thanks for any ideas.

Dan