Ask Frost King: Do I Need All Sides of the Foam Tape Exposed to Air for it to Begin Expanding?

Do I need to have all sides of the foam tape exposed to the air for it to begin expanding?
The answer is no. As long as the side opposite the adhesive is exposed to air, the product will still expand upwards. The sides can be completely covered in a tight wedge or groove, and you'll still get the benefits of expanding foam.