According to the international association of certified home inspectors or internachi most types of insulation have a life span much longer than homeowners might think.
Roof insulation life expectancy.
Housewrap wrap tape and spray foam last 80 or more years while loose fill foamboard cellulose fiberglass rock wool and loose fill all last 100 years or more.
A properly insulated attic keeps the home warm keeps energy bills low and protects the roof and home during a heavy snowfall.
Different types of insulations have different life expectancies so you may be able to estimate how long yours will last if you know when it was installed.
Built up roofing bur.
Cellulose insulation can last for decades fiberglass insulation up to 100 years and spray foam could outlast your home.
Foam roofs have a life expectancy of 10 to 15 years but can last twice as long if recoated after every five to ten years.
If kept dry undamaged and away from uv rays all of these insulating materials have a lifespan of 100 years or more effectively the life of the house.
For the most part maintaining attic insulation is pretty easy.