During the build, I noticed they used rolled fiberglas insulation. Don't know the "R" value, was thicker than what they put in the walls. They cutout 2 sections, placed one on top of the other, then placed between floor joists. They stapled the lower section to the floor joist. When they were all done with the insulation, they used a nylon netting all over the bottom. Stapled that to the floor joists. Floor joists are 2X12 under the house.
My opinion is was too loose fit, too much air travel in the joist insulated area. Is there a fix for this? Dave