Can Wet Blown-In Insulation Dry Out or Must It Be Replaced?

Blown-in insulation, usually cellulose or fiberglass, loses its loft when wet. Cellulose, made from paper, absorbs water like a sponge and can stay damp for weeks. Fiberglass resists water better, but the wet weight compresses it, leaving gaps that let heat escape.

Moisture also creates a perfect spot for mold and mildew. Once mold starts in insulation, it can spread to nearby wood and drywall. The pros can often dry a small, contained wet area, but if the insulation is soaked through, drying it evenly is nearly impossible.

Replacing wet blown-in insulation is often the safer choice. New insulation restores the thermal barrier and avoids the risk of mold growth. The pros usually remove the wet material, dry the cavity, and then install fresh insulation to the correct depth.

Removing wet insulation also lets the pros inspect the surrounding structure. They can check for rot, rust, or hidden leaks that caused the water in the first place. This step helps prevent the problem from happening again, which is worth the extra effort.

Act quickly if you discover wet insulation. The longer it stays wet, the higher the chance of mold and structural damage. Turn off the water source if it's a pipe leak, and remove any furniture or belongings from the area.

Avoid walking on the wet insulation, as that can compress it further. Open windows for ventilation if the weather allows, but don't rely on natural drying alone. Contact the pros for an inspection, especially if the water came from a contaminated source like a sewer backup. Policies vary, and your insurer decides what is covered.

• Turn off the water source if you can do so safely
• Move furniture and valuables out of the wet area
• Open windows to increase airflow
• Avoid stepping on the insulation to prevent further damage
• Call the pros for a moisture assessment