After returning home from a three week RV trip Saturday to discover our central AC failed while we were gone, repairs were completed late yesterday and we were able to finally move back into the house. One of the repair guys mentioned I might want to consider adding additional attic insulation as the blown-in fiberglass had compressed quite a bit over the past 20 years. He was right. I think I started out with 13 inches (R-38) but it looks like it has shrunk to no more than 6 to 8 inches on average.
I looked at purchasing cellulose insulation from Lowe's ($700 plus the free use of a blower) and doing it myself with the help of a couple of my grandsons. Then after calling a local insulation contractor who agreed to do the job for $1,000, I decided to forego the DIY option. This way if someone puts their foot through my ceiling it won't be me or a family member - and I won't pay until it is repaired.