I found mouse or rat dropping in the garage in our 'new' house. I cleaned it up thinking that maybe it was old.
The other day I saw more droppings.
The garage door faces the back alley where our trash cans are. There is about an inch or two of a gap between the floor and the bottom of the garage door.
How do I seal this space to prevent vermin from entering the garage?
Note: the garage door swings up it does not roll up.
Install weatherstripping on bottom of garage door. From the pics, I can't tell if the garage door rolls up or swings to open.
If the door rolls up, the weatherstripping can be installed on the very bottom of the door. Weatherstripping comes in various shapes and thicknesses. Filling a 1 1/2" to 2" gap seems excessive, but possible.
If the door swings, then the weatherstripping will rub on the floor so you need a threshold mounted on the floor and directly under the garage door. Then you can install weatherstripping on the door and have it "reach down and touch" the threshold. So, when you swing open the door, the weatherstripping will "come off" the threshold and not touch the slab.
Remember, those vermin can squeeze through a very tiny hole, COMPLETELY fill the gap.
From the photo I can't tell what the scale of the door is or if the gap is due to an uneven concrete surface, but you may be able to adjust the garage door to close or reduce the gap making it somewhat harder for the Rodents Of Unusual Size to enter:
Make sure the door isn't binding anywhere. Should be fairly obvious if you disconnect the electric garage door opener, if you have one, and opening the door manually.
If you're using an electric garage door opener it should allow you to adjust the open/close distance. Look on the back or side of the unit for knobs or screws that you can turn to increase the close distance. Don't confuse them for the adjusters that control the open/close force. Every unit is different so look up the manual first if you can. If you can't find one start with a 1/4 turn at a time, run a full open/close cycle, and try again.
The spring(s) force need to be adjusted, but I don't recommend this because they can be dangerous. Find a garage door contractor.
Weatherstripping or no, the real answer is: you can't. They'll find their way into anything, even the NORAD command center :-) . Best thing to do is keep the garage & basement as clear of edibles as possible, and when (not if) mice show up anyway, start putting traps or poison in locations inaccessible to kids or pets.
There's specialized weatherstripping and door sweeps sold by this xcluder company. They produce this metal wire filled fabric and certain metal end piece crimp clamps that discourage rodents from chewing through them.
I'd try one of their door sweeps.
https://buyxcluder.com/xcluderr-residential-pest-control-door-sweep.html
