This picture was taken during a home energy assessment. Homeowner complained that the second-story room above an unheated garage was always cold. I cut a small hole in the garage ceiling and snapped this photo. Someone had tried to put fiberglass batts (R-11 as you can see from the photo) designed for 16" wall cavities into the cavity between the 12" on center floor joists. To make them fit, they folded the batts into an inverted V shape.
The homeowner is removing all of the drywall and having the entire area spray foamed.