Does Insulation have a life span…
According to INACHI (but I don’t know where they got their source from)
As long as they are not punctured, cut or burned and are kept dry and away from UV rays, cellulose, fiberglass and foam insulation materials will last a lifetime. This is true regardless of whether they were installed as loose-fill, housewrap or batts/rolls.
INSULATION & INFILTRATION BARRIERS
Black Paper (felt paper)
15 to 30
From InterNACHI’s Standard Estimated Life Expectancy Chart for Homes - InterNACHI http://www.nachi.org/life-expectancy.htm#ixzz2cVSE8e00
That’s could be true in a conditioned attic or crawlspace I suppose.
It’s a rare event if I don’t recommend new insulation. Most I see is close to 40+ years compressed and needs covered over with new to raise the R value.