i had the same problem, barry. you have to go under the house and measure the distance between the joists. if they are either 16in. centers or 24in. centers, you lucked out. just buy roll fiberglass insulation and stick it up between the joists, using the bendable metal holders Home Depot sells for just that purpose(they are located where they sell metal joist hangers). its a miserable job, but when your house is nice and warm, you'll be glad you did it.