I believe you have tar paper under your siding based on your description.
How to seal wood siding to concrete.
Crawl around the exterior of your home and use a flashlight to find cracks holes and gaps.
Oil based stains penetrate the wood more deeply than water based.
Find the entrances mice use to enter your home.
Most houses in america get foam sill seal laid on top of the foundation.
Theoretically you could seal the tar paper to the foundation with foam spray caulking something similar.
Apply wood sealer with a brush roller sprayer or by dipping.
Note that there are various types of caulk.
That could be accomplished with perhaps metal flashing j molding dap230 caulking vinyl separation or other suitable stop.
A garden pump up sprayer is the simplest method.
For masonry the sealants are the go to product.
The best solution here may be to clean up that area of all debris let it be fully dry and then apply a bead of qood quality exterior grade caulking material.
This plastic foam product primarily works as a capillary break between the concrete and the framing.
Cleanup is with mineral spirits.
Sealants protect concrete and wood from moisture but do not stop water movement through the concrete from the outside.
Buy yourself a caulking gun learn how to mount and open a tube of caulk and go to it.
One of the more interesting wood sealers is the sikkens brand rubbol siding finish.
Stains are used on wood to enhance color and make them weather resistant.
This answer is not useful.
Then caulk all joints with a high grade 50 year paintable silicone or polyurethane product to prevent water from getting behind the siding.
How to seal siding to keep out mice.
Prime all bare spots with a high grade oil based primer.
Since some of the siding looks like it will need re priming and painting make sure that you use a paintable type of caulk.
When sealing wood surfaces must be free of all mildew dust dirt oil soot grease and other contaminants.
As porous as concrete is its not even ideal that treated wood meets concrete.
My recommendation in this scenario would be to trim the wood siding 1 4 inch minimally or better yet 6 to 8 above the concrete area.
Look under the siding at the area meeting the foundation of your home for holes and gaps.
You need to isolate the wood itself from the concrete.
Not a vapor barrier as you say but it prevents water that makes it past the siding from getting any further into the wall.
Tinting a standard white primer a shade or two lighter than the finish coat improves coverage.
Wood meeting concrete in a damp area is never a good recipe.
This is mostly because of the chance for standing water or leeching.
When it comes to air sealing one of the areas that we rarely see done well is the joint between the foundation and the framing.
Your first attempts won t come out very well messy lots of holes goop all over the concrete and the wood stiff fingers and sticky stuff all over your clothes and hands.
Dap230 clear makes a good water resistant caulking that can be painted and is permanently flexible.
