The Blog

What Should I Do When My Insulation Gets Wet?

By Chuck Henrichsen on September 3, 2014

My Spray Foam insulation is wet:

You’re in luck! If you have closed-cell spray foam insulation that’s been exposed to moisture, never fear. Closed-cell spray foam insulation provides a moisture barrier and an air-tight seal. If you’re noticing water on your spray foam insulation, it almost certainly means that you’ve got a leak somewhere. But don’t worry—the water won’t have penetrated the insulation itself, and it should simply evaporate from the surface. If you can, grab and towel and wipe down any excess water you see to help protect the wooden support or permeable parts of your home.

My Fiberglass insulation is wet:

Don’t worry—things could be worse. The individual fibers in fiberglass insulation are made from water and recycled glass, so it won’t absorb the water. Even when it gets wet, the fibers themselves remain structurally sound and functional.

Unfortunately, however, when water accumulates in the air pockets of fiberglass insulation, it drastically reduces its insulating function. Water easily conducts heat, so when the warm air of your home presses up against the insulation, it will quickly be conducted straight out of your home. This is a problem that needs to be fixed.

What should you do? Try to help your insulation dry out. If it’s in your attic or your crawl space, placing a dehumidifier or a fan in the area will help to dry it out. If you can, lift out the batts that are affected and move them to a warm dry area to dry, being careful to wear gloves, protective clothing, eyewear, and a mask so that you don’t inhale the fibers. Carefully watch your insulation for the next couple of weeks. If it starts to have a funny smell, it’s a sign that the water that contaminated the insulation was dirty. You’ll need to replace it all.

My Cellulose insulation is wet:

When your cellulose insulation gets wet, you need to sit up and pay attention. Cellulose is plant fibers, in most cases recycled newspaper. While it wins plenty of points for being a ‘green’ option, it can be hard to handle after it’s been exposed to water.

The plant fibers of cellulose wick water right up. If your leak is very small, you may be able to simply remove the affected area of cellulose insulation and let it dry out (that will take a while). If the leak is more extensive, the cellulose will have wicked up the moisture and spread it throughout a large area. Unfortunately, wet cellulose allows mold and mildew to form within a few days to a week. Total removal of the insulation will be necessary. On the bright side, in some instances the cellulose batting has been successfully dried and replaced into the same space (which would have been thoroughly cleaned to prevent mold).

My Cotton insulation is wet:

Cotton insulation, as again a plant fiber, is prone to collecting moisture. It is more easy to dry out than cellulose insulation, however, and the same principles may be used when considering a wetted area of cotton insulation. If a small area has been damaged, it can be removed, dried, and replaced. It’s important to be aware, however, that if your cotton insulation has been repeatedly wetted and dried, the chemical treatments that deter fire and pests may have leached out.

If the cotton insulation has been saturated, the entire section of insulation will have to be replaced. Inquire with your insulation crew whether or not any of the insulation will be able to be salvaged. If mold has started to grow on it, you’ll have to scrap it.

My Foam Board insulation is wet:

Not to worry! Foam board insulation is made from similar materials as spray foam insulation. This makes it mostly impermeable to water, and an unlikely host for mold or mildew growth. It is important, however, to make sure that your foam board is dry. There have been cases in which foam board, as it is impermeable to water, creates a seal that traps moisture in an area of the home, such as a wall. The wooden beams and sheet rock are not resistant to water—they will become damaged and may need replacing.

If you notice your foam board has water accumulated on it, take a towel and thoroughly dry it off. Have a professional inspect the area to make sure that water isn’t trapped somewhere it shouldn’t be.

If you’re curious about other aspects of insulation, such as the varying R-value or environmental impact, take a look at our recently released free eBook download. In this we discuss all these aspects and more about the 5 most common choices of insulation in the Seattle, Marysville, Everett, and Arlington areas.

If you’ve noticed you’ve got a water issue, contact our team of insulation experts for a free consultation.

Chuck Henrichsen
President and CEO of Clean Crawls, Treasurer of E3 World Wide, proud husband and father.