If you open up your attic and find mold growing in your insulation, it's normal to feel a little panicked. After all, mold can cause health problems like nausea and asthma, and you've probably heard horror stories about homes being completely taken over by the stuff. The good news is that moldy attic insulation is actually quite common. Most of the time, as long as you deal with it promptly, you don't have anything to be concerned about long-term. Here's what to do.
Find out how water is getting in
Before you eradicate the mold, you need to find out what's making your attic moist. Otherwise, any eradication measures will be wasted because the mold will come right back.
The most common cause of moist insulation is a roof leak. Put on some gloves and a face mask and venture into the attic. Do you see any spots where the insulation is wetter than in others? Is there water seeping in through the roof anywhere? (This would be most obvious after a rain storm.) Also, take into account the age of your roof and whether you can see peeling shingles from the outside. If you see signs of a leak or otherwise think your roof may be to blame, call a roofing contractor to investigate and make the repairs.
If you have pipes running through your attic, perhaps one of them is leaking. Have someone turn the water on in the home while you watch the pipes for any water that beads up or drips out. Call a plumber if you spot a leak.
The third possibility is that your attic is not well ventilated. This can cause moisture to build up inside, especially on humid days. Try opening the attic on a humid day; if you're greeted with a blast of sticky air, have your roofing contractor add more soffit vents or perhaps an attic fan.
Dry out the attic
Once the source of the moisture has been addressed, don your gloves and face mask again and put all of the old insulation into contractor bags. Then, put a dehumidifier in the attic and run it for a few days to ensure any residual moisture has been removed from the air.
Note: When pulling up the old insulation, note whether there is also mold on the walls, floor, and ceiling of the attic. If you do spot mold on the structure itself, you're dealing with a much bigger problem. You're best off calling a mold remediation team so you do not expose yourself to too much mold or risk damaging your structure.
Replace The Insulation
Purchase some new batts of insulation and roll them out. If the proper repairs were made to prevent additional moisture from entering your attic, this insulation should remain mold-free.