What Does Asbestos Look Like?

As a home inspector, I often get asked what does asbestos looks like. The reality is that asbestos is a mineral that is mined. It basically looks like a rock. There are six main types of asbestos but to the untrained eye, they just look like rocks.

Raw asbestos goes through a series of crushing into small pieces. At each stage, the asbestos fibers are vacuumed out and moved by air through a series of filters. Once separated by the filters, they are packaged and sold to be used in asbestos materials.

What Materials Contain Asbestos?

Asbestos was used in thousands of products before it was known to be a hazardous material. In fact, according to the Scientific American, the first known written reference about asbestos was around 300 BC. Theoprhastus, an ancient scientist, wrote about a rock that looked like rotted wood. He explained that it could be burned and not be harmed. During that time, asbestos was woven into cloth that could be burned for cleaning and whitening.

Con artists would even sell asbestos crosses and robes as relics of Jesus Christ. They would set the “relics” on fire to “prove” to their authenticity. Their gullible audience paid top dollar for these relics.

It wasn’t until the 1860’s when asbestos finally made it into building products. Its fire protection qualities made it a great material for roofs. During this era, house fires were common and spread quickly from house to house. After that, the construction industry used many asbestos containing materials into the building process.


Knob and Tube Wiring

Knob and tube wiring is a wiring system that is found in older homes (built in the late 1800’s to about 1940). It consisted of two wires. There was one hot wire, and one neutral wire. The wires were insulated with varying types of thermal insulation, such as rubber insulation, or asbestos treated cotton insulation.

Homes with knob and tube wiring may have asbestos.

Vermiculite Loose-Fill Insulation

Asbestos can be found in the attic insulation of older homes in the form of vermiculite.

Vermiculite insulation looks like pebbles, or gravel. It is poured into an attic floor, and sometimes the walls. Vermiculite does not contain any asbestos in its natural state. However, most of it in America comes from mines in Libby, Montana. These mines were near a natural deposit of asbestos. Accordingly, the vermiculite was tainted by asbestos fibers from the asbestos vein. The EPA (Environmental Protection Agency) states that you should assume all vermiculite is contaminated.

Asbestos Siding

asbestos siding is dangerous in poor condition

There are many asbestos cement products. Asbestos fibers were often mixed in with cement to strengthen it and make it fire resistant.

Asbestos siding is one of the most common asbestos cement products. It has a very distinct vertical grain pattern and the bottom can be flat or wavy. Since it is outside and non-friable, it is generally not a concern. But if it is damaged, or you want to have it removed, it can release a lot of asbestos into the air.

Asbestos Roofing

Asbestos roofing is another common asbestos cement product. They look similar to slate, but have a more fibrous look when cracked or damaged.

The photos in the slider above were provided to me by a fellow inspector, Andrew Wuench.

Just like asbestos siding, asbestos roofing doesn’t pose much of a health risk. It is outside and generally non-friable. However, most asbestos roofing is at the end of its life. Due to the occupational risk of removing it, it is much more expensive to replace than a traditional roof.

Popcorn Ceiling

Asbestos in popcorn ceilings

These ceiling treatments were the bee’s knees for many years. However, now we know now that there could be asbestos in popcorn ceilings applied before the early 1990s.

Spray-on texture, also known as popcorn texture, was a blessing for contractors starting in the 1950s. Contractors used popcorn ceilings as an easy way to hide imperfections. Additionally, popcorn ceilings are fire and sound resistant.

A simple hand touching the ceiling can release asbestos fibers into your home.

Asbestos Pipe Insulation

Due to its resistance to heat, asbestos was used to insulate hot water pipes. It is often found on boiler pipes, and hot water distribution pipes in older houses.

Air pockets created by alternating layers of corrugated and flat asbestos sheets created insulation.

Asbestos pipe insulation is considered friable and most of it today is in poor condition.

Asbestos Tiles

Vinyl floor tiles containing asbestos were extremely popular. They were very durable and easy to install. The most common size of the tile was 9×9, but there were also 12×12, and 18×18 tiles that contained asbestos. If you have a loose tile in your home and see black adhesive underneath, it likely contains asbestos as well.

The second and third photos above was provided by fellow home inspectors, Zack Gillepsie and Matt Mickinney respectively.

Asbestos Ceiling Tile

asbestos ceiling tiles do not have a distinct look

Asbestos ceiling tiles had great acoustic properties and were used in many commercial buildings such as churches and auditoriums. However, they were also used in homes for finishing the basement.

They look similar to ceiling tiles today. If your home was built, or renovated between 1950 and 1980, then it is possible that your ceiling tiles contain asbestos. 

Transite Vents

transite is like asbestos chimney

Combustion appliances such as furnaces and water heaters need vents to convey dangerous byproducts to the exterior of the home. Generally, metal vents are used. But during the asbestos boom, transite vents were used. These were asbestos cement vent pipes designed to vent combustion products to the outdoors. The benefit of course was their extreme resistance to heat and fire.

They are essentially asbestos chimneys.

The photo above was provided to me by a fellow inspector, Andrew Wuench.

Asbestos Duct Tape and Insulation

look for asbestos duct insulation
look for asbestos tape on hvac duct work

Asbestos was used in tape to seal the joints of HVAC ducts, as well as insulation that covered the dust. If your home was built around 1985 or before, the HVAC duct work might have this asbestos-containing material.

So, What is Asbestos?

Asbestos is a naturally occurring product that is great at resisting heat. As discussed, it has been used in many materials for thousands of years.

The good news is that only friable asbestos is considered to be dangerous. Friable means easily crumbled. Materials that are crumbly will release fibers into the air. Inhaled fibers get permanently stuck in our lungs. This is what causes lung diseases such as asbestosis and mesothelioma.

Asbestos products like siding, floor tiles, and transite are generally non-friable asbestos and aren’t able to cause any health issues. However, loose insulation, popcorn ceilings, and pipe insulation are friable and are a health hazard. Also, any asbestos in poor condition can release fibers.

vermiculite insulation can cause mesothelioma

How to Test for Asbestos?

There are many health risks involved with asbestos exposure including lung cancer. Obviously it is a good idea to find out if you have it in your home. Testing is the only way to know for sure if a material contains asbestos. Although you can hire a professional to test your home for asbestos, there are many DIY kits available.

Always follow the instructions that come with the asbestos test kit. Be safe and wear the proper PPE.

Generally, you only need a small sample the size of a quarter. Then, you put the sample of the material in the provided sample bag. Lastly, you send it off to the asbestos testing lab.

The asbestos testing kit below comes with all your PPE, instructions, and the lab fee.

how to test for asbestos Asbestos Testing Kit

  • Lab fee included
  • 1 Day lab Turn around
  • PPE included

What if Your Home Tests Positive for Asbestos?

If your home does contain asbestos, then your next step depends on its condition. Remember that only friable asbestos is a health hazard. If it is in good shape, then you may be able to live with it. Otherwise, if you have crumbling areas, water damage, or renovations requiring demolition work, then removal or encapsulation is your best option.

Federal regulations do allow homeowners to handle their own asbestos abatement. However, asbestos removal is best left to a professional. Asbestos contractors are trained in the safest way to to remove asbestos without toxic fibers contaminating the rest of the house.

Do Home Inspectors Check for Asbestos?

InterNACHI (International Association for Certified Home Inspectors) is the largest and most respected home inspector association. They state that home inspectors are not required to inspect, or test for, any environmental hazards. This includes asbestos ceiling materials.

That being said, many home inspectors do point out items that they suspect may be ACM (asbestos containing material). However, there are millions of products that contain asbestos and home inspectors only perform a limited, visual inspection.

Likewise, it would be impossible for a home inspector to know every material which may contain asbestos let alone test every suspected material.

Bottom Line on What Asbestos Looks Like

There are many different products in older buildings that contain asbestos. As discussed, the presence of asbestos is a health risk. Your risk of exposure is directly related to the materials condition. If you suspect you have asbestos in your home, you should definitely test it, or have it tested.

All treatment, abatement, removal, and disposal of asbestos should be handled by a qualified asbestos professionals.

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