Mouse-proof exterior of home?

[Dave K.]

We have mice that get into our split-level home in Minnesota. They fall into
the walls in our lower level, can't get out, die & then rot and stink up the
house.

Last fall, after talking to an exterminator and finding out what they do, I
went around the outside of our house inch by inch, at ground level, and
filled every hole I could find with steel wool. I found some big holes where
our masonite siding connected in corners, and I found holes where the siding
stopped and the chimney bricks began. Wherever I could, I reached up under
the siding to try to feel holes, but in many cases there were gaps between
the siding and the foundation, and I couldn't reach up very far to see if
there were holes higher up.

Anyway, because I did fill some larger holes, I thought I had sealed up the
house and was hopeful that the mouse problem was over. We didn't find any
mice (or the dead mice smell) in our house at all the following winter,
spring and summer.

The last couple weeks, however, the same thing as last fall is happening and
mice are in our walls again. I checked the holes I plugged with steel wool,
and they are still plugged. I think my only remaining option to mouse proof
my home now is to somehow fill the gap between the siding and the cement
foundation because I can't figure out any other possible place that they can
enter. The gap ranges from something you can fit a pencil into to something
you can fit a finger into.

Anyone have ideas on how to quickly and easily fill this gap between the
siding and foundation? It will be a painstaking process because I'll have to
do maybe 50 feet around the perimeter of the house. Can I use the expanding
foam, or will that push out the siding and wreck it? Would the minimal
expanding foam work? I've heard that mice can chew through any of these
foams ... but I figure that maybe I can at least fill the gap, and in a few
months, see where it gets chewed through ... then I'll be able to narrow it
down a little bit, and know where they are getting in. Or maybe there is
something better than foam that will either help me figure out where exactly
they are getting in or that will help seal up the gap between the masonite
siding and foundation. For instance, if I bought some cedar trim boards, and
glued them to the bottom of the siding and the cement foundation, to block
the gap, would that work? Is there any glue that will work on wood boards,
masonite siding and cement?

Any ideas on how others have filled the gap between their siding and
foundation, or ways to figure out where exactly the mice are coming in,
would be greatly appreciated!!! I'm not looking for mouse-trap advice ...
I'm looking for ideas on how to mouse proof the exterior of the home so they
don't get in at all. Thanks for your help!!

[t***@adelphia.net]

Dave, what I think has happened is the mice have chewed new holes to gain
entrance into your home. The meaning of the word Rodent is a gnawing animal.
They have to continuously gnaw of their teeth when they close their mouths
will pierce their brain killing them. What I would recommend would to be use
a combination of the minimum expanding foam with steel wool. Place the steel
wool in the opening to be sealed and then stick the tip of the foam into the
steel wool and let it expand into the steel. That was when mice try and chew
through it they will ingest some of the steel wool and it will kill them by
causing their stomachs to bleed. It sounds to me like you have done a good
job, it is just to a point where it needs to be either touched up or re-done
to keep these pains out of your house. The best thing you can use is a
product called "Stuff It." I think you can buy some on
www.doityourselfpestcontrol.com This stuff is made of brass and the mice
cannot chew thru it. It has larger "links in it so when the rodents start
chewing their teeth will get caught and they have a hard time getting away.
Then they will not come back again.

I hope this helps in some way...

[Eric Lee Green]

Post by Dave K.
Any ideas on how others have filled the gap between their siding and
foundation,

A word of warning -- this gap between siding and foundation is necessary
in order to allow water to drain that gets behind the siding (siding
protects the Tyvek or asphalt-impregnated felt that provides the
actual waterproofing, it is not, in itself, necessarily waterproof).
Interfering with water drainage can cause your house to rot, especially
under the windows where water typically gets behind the siding and
weeps downwards. So if you intend to block this gap, block it with something
that'll let water behind the siding escape.

I don't have any suggestions regarding your mouse problem, other than
to get a couple of cats. (Even my sedentary lap warmers, never
confused with mighty hunters, managed to eliminate my mouse problem
when allowed to roam outdoors, albeit they left the rodents as gifts
on my doorstep rather than actually eating them). You might put baits
out in outbuildings 10 yards or more from your house, in hopes of
reducing the neighborhood mouse population before they get to your
house.

I've never seen a mouseproof wooden home. Just one where the mice have
been killed before they get into the home.