sealing foundation from pests
I have a mid-60's ranch on a slab in eastern MA. I have a large mouse problem in my walls and attic. I am 99.9% that their prefered path in is via openings and gaps near the sill and under the exterior sheathing. I have had extensive termite damage, so I am sure there are access points from termite damage that we have not yet uncovered. (we have worked our way 60% around the house,fixing as we go).
The sill is only a fir 2x4 on the slab, with the 2x4 wall foot plate on top. The slab is only 1 - 6" above ground level depending on what part of the house you look at. Ground slopes away. Most of house is under 2' roof overhang, except for two side walls.
My concern - If I stuff the voids under the exterior sheathing with copper mesh and expanding foam to block access to the sill, am I risking any kind of water - moisture damage - as I would now be blocking any run-off escape or 'breathing room'?
Re: sealing foundation from pests
I know this is not what you are asking but might be helpful. The foam is not go for rodent control, they will eat it. I am not saying not to use it for insulation purposes. The mesh will work. If you block the entry and exits they will end up in the living areas. You need to rid yourself of the mice before you do any of that. I don't think stuffing with mesh will solve the problem. They will find away around it. If you staple it up and as a "fence" you will be better off. I also recommend just using snap traps the [URL="http://www.victorpest.com/store/rodent-control/m154"]old fashioned kind [/URL]not the ones with fake cheese. At 50 cents a piece you can just throw them away. Place them on cardboard and you need not even touch a mouse. Also 2 parallel to the wall facing away so the pedal is the first thing they touch. You don't even need to put any bait on but it helps. After they are gone and you seal things up continue to use the snap traps inside. I don't like poison they die in weird places. If they die in the wall you will end up with an odor and possibly maggots and the end result is flies in your house. Continue to be vigilant with the traps. Use them outside too. If the problem is that bad did you just let it get away from you or are you in a location that is more susceptible to rodents?