I have a 1982 house in southern California with a stucco exterior. The drip cap at the bottom of the stucco walls is rusted out in many places, which allows air penetration into the walls. I assume this is adversely affecting my insulation effectiveness, in addition to allowing bugs and moisture free access.
Should I attempt to seal this? I was thinking of using expanding foam, the kind for large gaps. Are there any issues with doing that? Since it will underneath the wall, there should be no issue with UV on the foam. Although we get about 14 days of frost, we do not have any extended periods below freezing. But we do get a summer in the high 90's and 100's, so insulation is important.