A little piece of every decade sticks with us longer than maybe necessary, and in the case of many homes across America, this is fiberglass insulation from the 70s. There are many once hip trends like colored paisley counter tops or roller disco, but all great things must come to an end, and so must the time of the fiberglass insulation. It is a terribly inefficient method of thermal insulation and it is time to get upgraded with blow-in cellulose insulation.