Does Rock Wool Insulation Contain Asbestos?

If you have blown-in insulation in an older home, it is possible that it is a rock wool-style of insulation. But does rock wool insulation contain asbestos? It may, as some companies added asbestos to insulation at the time of manufacturing, but some did not. An asbestos inspector can help you determine what you have.

Determining if My Rock Wool Insulation Contains Asbestos

This is more complicated than it may seem at first glance. It is important to understand the difference between branded and non-branded rock wool insulation.

Non-Branded Rock Wool Insulation

Many types of blow-in insulation carry the name rock wool insulation (also called mineral wool insulation). Its texture is fibrous, almost resembling cotton fibers. Typically it has a light gray or white color.

Many companies over the past several decades sold rock wool-style insulation. It consists primarily of basaltic rock melted at a high temperature before the manufacturer spins it into fibers for use as insulation. Because it is made of rock, it is resistant to fire. Some companies chose to add asbestos to further enhance its fire resistance, while others did not.

Branded Rock Wool Insulation

The Rock Wool Manufacturing Company began operation in 1943, creating blown-in rock wool insulation, which it branded as Rock Wool. (Confused yet?)

If you know that your home contains Rock Wool-branded insulation, you may have a problem. The Rock Wool Manufacturing Company was one of the companies that sometimes added asbestos to its product. With Rock Wool-branded insulation, you should seek testing. 

Because of lawsuits related to the inclusion of asbestos in Rock Wool’s insulation, the company filed for bankruptcy in 1996.

Can You Spot Asbestos Insulation Without Testing?

What does asbestos insulation look like? Unfortunately, it is nearly impossible to determine if rock wool insulation has asbestos by sight alone. Ultimately, the best way to find out whether your rock wool insulation is dangerous is to hire a professional inspection company.

Why Asbestos in Insulation Is Dangerous

Asbestos is a potential cancer-causing material. What does asbestos look like? It consists of fibers that resemble cotton; however, when manufacturers place it into products, it may no longer look like cotton. It is almost impossible to look at a product around your home and know if it has asbestos.

Regardless of the product in which it appears, asbestos can be dangerous. Even if it no longer resembles cotton, it still can release microscopic fibers when disturbed. If you disturb rock wool insulation and it contains asbestos, you could release the dangerous microscopic fibers into the air without realizing it.

When fibers become airborne, someone could inhale them without knowing it. You would have no symptoms at the time of exposure. A couple of decades later, though, you could develop a type of cancer related to asbestos exposure, such as mesothelioma or lung cancer.

Although the fact that asbestos causes cancer was well known by 1950, the Environmental Protection Agency (EPA) did not ban the use of new asbestos products until 1989, which is why any homes built in the 1980s or earlier could have products containing asbestos.

What Should I Do if I Might Have Rock Wool Insulation?

If you suspect rock wool insulation that contains asbestos, do not disturb it. Instead, call a local asbestos testing company to do an inspection. As long as no one disturbs the material, it will not release fibers into the air; however, you do not want to ignore the problem, as someone could disturb it accidentally, creating an exposure.

Cost to Test for Asbestos

The asbestos testing cost averages almost $500. It can be as high as $2,000 if the testing is highly involved or requires the inspector to enter hard-to-reach spaces of your home.

Additionally, if you believe there could be other products that contain asbestos, you may want the inspector to look at the entire house and every potential source of asbestos. This drives up the cost for the inspection, but at least you will know whether the home is safe. 

Other Areas of Your Home That May Have Asbestos Materials

Where is asbestos found? Attics, walls, siding, ceilings, floors, and other locations all could have items that contain asbestos in an older home. Beyond rock wool insulation, some materials in your home that may have asbestos include:

• Siding: What does asbestos siding look like? It has a greater feeling of density than modern siding, and it often has two or three nail holes along the bottom of a panel.

• Flooring: Flooring tiles installed before 1990 could have asbestos in them, but testing is the only way to know for sure. Removal of asbestos floor tiles is an option, as is encapsulating them.

• Floor adhesive: Black floor adhesive, also called black mastic, may contain asbestos, especially if the flooring installation occurred before 1990.

• Pipe insulation: Wrap-style insulation around hot water pipes may have asbestos. What does asbestos pipe insulation look like? It has a gray-white cover over a material that resembles corrugated paper.

• Vermiculite insulation: Loose-fill vermiculite insulation could have an asbestos contamination. It almost resembles Styrofoam packing peanuts with a square accordion shape. Learning how to remove vermiculite insulation safely may require the help of a pro.

• Ceiling: Older popcorn ceilings and ceiling tiles could have asbestos. Removing a popcorn ceiling or a tile ceiling requires the help of a pro when it may contain asbestos.

How Does a Pro Remove Rock Wool Insulation?

Typically, a professional removes rock wool insulation that may contain asbestos by vacuuming it using a machine with special filters to pull fibers out of the air. It is also possible that the pro will seal off the area with plastic and then remove the insulation by hand into sealed waste containers.

Professionals from a local asbestos removal company will make use of special clothing and breathing gear to work safely. You almost certainly will not have access to the same level of safety gear as the pro does, which is why DIY removal is not recommended.

An average asbestos removal cost is about $2,200, but you could pay anywhere from $450 to $6,000, depending on the amount of insulation involved and the ease with which the pro can access the areas.