We're going to put spray foam insulation in our new west-facing sunroom because there's not a lot of wall space to put in batting and we need every R-value we can get. We talked to a spray foam guy today and he said:

1. The foam R-value is 14, but he said it was 40% better than R-14 fiberglass because it blocked all air flow. Is this true?

2. We've got ridge vents in our roof, and he said they'd spray the foam directly on the rafters, covering up the opening to the ridge vent. That sounds rather counterproductive. Don't we need to allow the air above the ceiling but below the roof to have a way to escape?