Because insulation can move or degrade over time, older homes are particularly in need of insulation removal or insulation replacement. Additionally, the required thickness and installation methods of insulation in homes have changed over time. It is very typical for a home built prior to 1985 to be inadequately insulated.
Your attic is not the only place in the home that is in need of insulation upgrades. Here is a home we are working on that was in need of drastic wall insulation upgrades. It just so happens these homeowners were doing a full renovation to remove old popcorn ceilings and warped sheetrock, so we can get a good look at the difference proper wall insulation makes.
(Notice the gaps all around the wall insulation. These open spaces allow what you don’t want in your home: moisture, unconditioned air, and even pests. This thickness of insulation is no longer adequate to pass code. And, you will see that the fiberglass batts are compressed, which means reduced effectiveness.)
(This is the same wall insulated with cellulose insulation. There are no gaps, and the coverage is thick. This bedroom is going to be more quiet and cozy than ever before. Fewer bugs will be able to sneak into the room now that is has been re-insulated. Great thing, since this is a little girl’s room!)