Blown-in insulation costs range from $750 to $3,800, with an average cost of $1,725 for insulating 750 square feet of attic space.
Fiberglass insulation usually needs replacement after 15-20 years as it can become dirty, wet, moldy, and less effective.
For stapling insulation, 20-gauge staples are recommended, though 19-gauge and 23-gauge staples can also be used.