If your rigs are built prior to Heartland changing over to a laminated floor, the best and most logical way to do this is remove the vinyl flooring and using a stud finder, drive more screws into the studs. I tried shimmong the floor from below but it started to squeak again within a few months. I also did the laminate flooring at the same time. Much easier and more solid than replacing the vinyl. At least for me. I currently have a pretty large area in the bedroom that squeaks but have not attempted to fis yet. I'm hoping to be able to get it from the basement storage area with construction adhesive.