I am going to insulate my floor above my crawl. I have ducting that runs between the joists in some spots. What is the proper technique for insulating these runs? Do I use thinner insulation and jam it into the little remaing space? or? Yes I have a vapor barrier on the floor, the crawl is vented, and the the face of the insulation will up towards the floor. Thanks, John P.S. I can take pictures if necessary.