Spray Foam Sealant

Check HERE.

Not sure if it's approved for sale in California though...pretty nasty stuff if you read the MSDS sheets..and you know how California is with "dangerous" stuff....Dennis

On edit: it appears it's available at KMart stores in both NorCal and SoCal..according to their website....Dennis

I have been satisfied with Great Stuff from Home Depot to seal gaps at home and in our RV.

If you use it, remember, that stuff swells up a lot bigger than you think.

there are at least two varieties, on that doesn't swell up quite as much.
bumpy

Great Stuff has several different products, the normal expanding (2x), a minimal expanding foam, and a 3x expanding foam, use the one appropriate for the size holes you have to fill.

not just appropriate for the size of holes, for the effect that extreme swelling might be, pushing out side paneling, etc.
bumpy

great stull also has one now that repels bugs and rodents

spadoctor wrote:
great stull also has one now that repels bugs and rodents

I've not seen that one, I'll look for it next time.