We moved into a 14 year old house 1 year ago and I have been crossing
items off the honey-do list at a good pace. Last week, SWMBO asked me
to look at the basement insulation, which we knew had some mice
issues. The house had sat dorment for about 6 months before we bought
it (no one crazy enough to do all this work), so the mice had free
reign. As I started pulling down the fiberglass bats, the fecal
matter kept raining down. Ultimately, I ripped all of the insulation
down and still feel that it was the right decision due to the amount
I have been researching the insulation options and need help. Our
intention is to finish the basement into a playroom for the kids in
the near future. I do not want to have to repeat the expense/time of
ripping down insulation and cleaning the mess again. Right now I'm
leaning towards gluing rigid foam board insulation inbetween the
ceiling rafters and either screwing/gluing (or both) a layer of
drywall directly to the insulation for fire safety issues. The
drawbacks of the rigid foam as I understand it are that is not as safe
in a fire as fiberglass and its more expensive, but I don't want to
create another mouse highway in my basement with fiberglass bats.
My questions are these:
1. Is the rigid foam and the method I'm considering even going to keep
the mice out (at least in between the subfloor and the insulation)?
If not it not worth the expense.
2. If #1 is yes, is attaching a layer of drywall an adequate fire
retardent (SWMBO is big on fire safety)
3. If I use this method and eventually finish the basement; I will be
installing a drywall ceiling. Is it acceptable to then install a
drywall ceiling to the rafters (since I will essentially be installing
a second layer of drywall).
Here are the other considerations:
-Poured concrete foundation approx 8.5'
-the plan is to finish the basement, but not necessarily constantly
heat it, rather just heat it when its being used (I mention this
because I've read that it isn't even as important to insulate under
the 1st floor, but might be better to spend the money insulating the
basement walls instead)
-we've had an extreminator on contract since the dog "gave" SWMBO a
mouse in the old house. They have put out poison and are coming
tomorrow (first time they'll get a great look since the insulation is
gone). Point is we have a professional involved. They did mention
that mice aren't likely to chew through drywall. They just don't like
-Basement is mostly dry but now is ready for me to seal every nook and
cranny. Also will be looking for mice entry points.
-have not found evidence of mice protrusion into the rest of the house
except for the attic
Any help/opinions would be very much appreciated.