As a general rule, it’s best to remove and replace your attic insulation every 10-15 years. The frequency will depend on many factors, including:
The type of insulation: Fiberglass insulation requires replacement sooner than other types.
The climate: Insulation is more likely to wear down or grow mold in warm, humid climates.
The level of ventilation: Poor ventilation will allow moisture to accumulate in your attic or crawl space.