Asbestos Identification

One of the most common questions a homeowner asks is “how can I identify asbestos in my home?”

Recognize Asbestos-Containing Products in Your Home

The date of the building can tell you a lot about asbestos risk. Buildings made between the 1940s and the 1980s are very likely to have used asbestos-containing materials. You will find that there are many materials containing asbestos that have been produced and distributed at the time.

Check the product name on the manufacturing label and do a web search to find out if it contains asbestos. If you have the original paperwork containing all the requirements for a certain product, you can check the product name and the manufacturer and do some research into the product to see if it contains asbestos. However, any product that was supplied prior to 1984 will almost certainly contain asbestos.

If the manufacturing label has a date from between 1940 and 1984, it has a higher chance of containing asbestos material. If the building was built in the 1990s and early 2000s, cannot contain asbestos materials.

How to Identify Asbestos Insulation

Homes built in the last 30 or 40 years have hot water pipes, steam pipes, and furnace ducts insulated with material containing asbestos. The most common type of insulation contains asbestos mixed with paper, textiles, or cement materials. Most-often, this asbestos insulating product appears as a blanket-type covering around the elbows and valves of your pipes. Check the information on the product label to determine if it contains asbestos.

Types of asbestos insulation:

Loose-fill insulation
Pipe wrap
Block insulation
Acoustic tiles and spray-on insulation

Asbestos insulation manufacturers:

How to Identify Asbestos in Ceiling Materials

Asbestos was common in ceiling tiles, tile adhesives, and ceiling texture sprays from the 1940s through the 1980s. In order to identify your ceiling pattern, remove a ceiling panel from the suspension system, turn it over, and look for an item number. Do some research into the product to see if it contains asbestos.

Generally, ceiling tiles made with asbestos are 9 by 9 inches (22.86 by 22.86 cm) or 12 by 12 inches (30.48 by 30.48 cm) white or off-white panels held up in a grid system.

Companies that manufactured asbestos ceiling materials include:

More on how to spot asbestos in ceiling materials

How to Identify Asbestos in Flooring Materials

Between the 19400s and 1980s asbestos was a popular material used in floor tiles. See if you can identify your floor tile collection name or model number; loosen a tile with a putty knife and wipe off the glue and drywall paper. There should be letters and numbers at the center of the back of the tile that indicates which one of the ceramic tile manufacturers in the USA made the product.

Asphalt Asbestos, Plastic Asbestos, and Vinyl Asbestos floor tiles during this period were sold in 6"x6", 9" x 9" and in some years 12" x 12" sizes and were quite a bit thicker than most of the modern tiles.

Asbestos flooring materials manufacturers:

More on how to spot asbestos in flooring materials

How to Identify Asbestos in Roofing Materials

Always consult the product label to determine if it contains asbestos. Labels provide clear information about the product by answering two simple questions: Where does a product come from? & What is it made of?

However, some asbestos-containing roof cement, coatings, and mastics are not labeled as asbestos-containing. Information about the dates of the roofing installation may also be sufficient to rule in or out the possibility that your roofing contains asbestos.

Companies that manufactured asbestos roofing materials include:

G.W. Berkheimer Company, Inc.
Barrett Roofing Company
Bird and Son
Fibreboard Corporation
Flintkote Company
GAF/Ruberoid
Johns Manville Corporation
National Gypsum Company
Reynolds Metals Company (Atlantic Asphalt & Asbestos Company)
Rutland Fire Clay Company
Keasby & Mattison Company

More on how to spot asbestos in roofing materials

How to Identify Asbestos in Wall Materials

Until the 1980s, manufacturers added asbestos fibers into drywall sheets, tape, and joint compounds to make them lighter, stronger and fire-resistant. You have to take into account that asbestos-containing joint compound may have been applied not only up to 18" wide over drywall joints but also in patches, repairs, around penetrations or fixtures, and in some buildings as a skim coat over an entire wall surface.

Asbestos insulating board (AIB) was also a commonly used material to insulate walls in residential construction. However, it’s very difficult to tell if an insulating board contains asbestos because they come in a variety of sizes, designs, shapes, and colors. Because of the hardiness and waterproofing qualities of asbestos, areas of the building prone to wet conditions like bathrooms, and laundries may have asbestos sheeting or asbestos vinyl tiles in the walls. Old homes may also have asbestos-containing soundproofing or decorative material sprayed on walls.

Companies that manufactured asbestos-containing wall materials include:

More on how to spot asbestos in interior walls

Howto Identify Asbestos Cement

Between the 1940s and 1980s asbestos was put into cement used on the exterior buildings to help insulate them. Thus, in order to identify asbestos in wall materials, think about your building’s main construction materials. Is it constructed from brick, timber, steel, cement sheet, or another material?

Asbestos cement products were used as siding and roofing shingles, wallboard, corrugated and flat sheets for roofing, cladding, and partitions, and in the mix used on copper water pipes. Fibrous cement sheets are easier to work with than concrete and more water-resistant than drywall, flat sheets of asbestos cement found their way into the interior of homes.

Companies that manufactured asbestos-containing wall materials include:

How to Identify Asbestos in Chimneys, Furnaces, and Wood Stoves

Asbestos has been frequently used to insulate wood-burning stoves as well as oil, coal, and wood furnaces. Usually, the fibrous material is contained in fireplace mortar, cement liners, transit flues, stiff paperboard, or paper and tape used for insulating and fireproofing. Artificial ashes and embers sold for use in gas-fired fireplaces, and some door gaskets in stoves, ovens, and furnaces may also contain asbestos.

All chimneys, furnaces, and wood stoves are required to have a rating plate for compliance. If you can find the metal plate on your fire, it will provide information about the manufacturer. For wood-burning stoves, for example, the rating plate can be found inside the firebox or on the back of the stove.

Companies that manufactured chimneys, furnaces and wood stoves with asbestos include:

More on how to spot asbestos in fireplaces

How to Identify Asbestos in Texture Paint/Coating

Millions of American homes built in the last 60 years were covered with paints containing asbestos additives. Asbestos spray coating was a commonly used way to insulate a roof and sometimes the sides of buildings from between the 1940s and 1980s. It looks like a rough layer of either white or gray paint. For example, if you check the underside of your roof in your attic, you will see a layer that looks like it was sprayed on.

Manufacturers of texture paint containing asbestos include:

More on how to spot asbestos in home paint

How to Identify Asbestos in or on HVAC Ducts

Between the mid-1980s and 1980 lagging cloth and asbestos-based paper was used by the HVAC industry to insulate pipes in heating and cooling systems within homes.

If you are inspecting the heating or air conditioning duct system, look for what may be asbestos-containing insulating material on the heating system white paper wrapped on the outside of some heating and cooling ducts. However, information about the age of your home and its heating system design and history could tell you precisely if your concerns are justified.

Manufacturers of asbestos-containing ducts:

How to Identify Asbestos in Window Putty

In many homes built before 1980, asbestos was added to the putty around the windows and frames for strength and heat resistance. The type of putty most likely to contain asbestos is the intumescent one, meaning that when the putty is exposed to heat, the material swells, increasing in volume but decreasing in density.

If the age of a window is not able to be confirmed or if the window putty is not included in the building register, if you can establish that it was installed before 1984, then most likely contain asbestos.

Manufacturers of asbestos putty:

Bondex International, Inc.
DAP, Inc
Hercules Chemical Company
Porter-Hayden
Synkoloid Company (Artra Group)

More on how to spot asbestos in window putty

How to Identify Asbestos in Water Heaters

In older heating systems, asbestos was commonly used as a liner for the heating system itself. Although asbestos can be difficult to identify with the naked eye, there are certain traits that make it easy to identifiable on water heaters: asbestos can be found in the insulating blanket within the metal cover and in the tank jacket placed around water heaters.

If you saved the certificate of manufacture, you could go to the company and find out from them if they used asbestos on that model water heater.

Companies that manufactured water heaters include:

More on how to spot asbestos in water heaters

How to Identify Asbestos in Adhesives

Because of their ability withstanding to very high temperatures, asbestos-based adhesives were used to patch seal joints on pipes and boilers. Additionally, asbestos adhesives were used in wallpaper, flooring, HVAC systems, in the finishes of countertops, cabinetry, and other fixtures.

Although asbestos fibers are too small to be seen by the naked eye, when wall panels are removed, the adhesive left behind is often visible as brittle old daubs. If you’re planning a home remodeling, you should determine whether your home was built before 1980.

Companies that manufactured asbestos adhesives include:

A.P. Green Industries
Amchem, Inc. (Benjamin Foster Company)
Armstrong World Industries
Celotex Corporation
Combustion Engineering, Inc.
Empire Ace
Fibreboard Corporation
Georgia-Pacific Corporation
Harbison-Walker Refractories Company
Minnesota Mining and Manufacturing Company
Mobile Oil Corporation
National Gypsum Company
North American Refractory Company
Johns Manville
A.W. Chesterton Seal
American Biltrite
Amtico Floors
Asbestos Corporation, Ltd.
Atlas Asbestos
Congoleum Corporation
Crown Cork and Seal
Foster-Wheeler
GAF Corporation
Garlock Packing Company
H.B. Fuller
Insul-Mastic Corporation of America
Owens-Corning Fiberglass Corporation
Pecora
Uniroyal B.F. Goodrich

How to Identify Asbestos in Gutters

Asbestos guttering, also known as asbestos cement guttering, was a popular building product used prior to 1980 in asbestos cement roofs. On outdoor roofs, asbestos cement can be found on a frequent basis in the form of gutter linings. In order to identify asbestos-containing gutters, try to find any codes or markings on the material. Once you’ve found a code, look for any information that the manufacturer stamped or printed. Sometimes you can find the meaning of the code and determine asbestos content.

Companies that manufactured asbestos cement guttering include:

More on how to spot asbestos in guttering

How to Identify Asbestos in the Fences

If your fence was installed pre-1980, then the best practice is to assume that it may contain asbestos. If your fence was installed after 1984 the chances are that it is either concrete or wood pulp, not asbestos. However, even though a house may have been built after 1990, if the neighboring properties are older, then the fence could have first been installed when those properties were built.

Visual ways to guide in identifying manufactured cement sheet fences made with asbestos-containing materials:

asbestos fences usually have 7 ridges per 1 meter wide panel, whereas non-ACM usually have 5 ridges
diamond washers, bolts, and nuts on asbestos joints
capping from the same material as the sheets - if it’s metal then you don’t need to worry about the fence being asbestos
exposed hair-like fibers

Companies that manufactured cement sheet fences made with asbestos-containing materials include:

How to Identify Asbestos in Tilux Marble Finish Wall Panel

Tilux sheets were well-known asbestos products used in place of ceramic tiles in wet areas, mainly in bathrooms, kitchens, and laundries. Identifying features of Tilux products:

stainless steel strip between the sheets
floral, geometric, and speckled patterns and the pastel shades of pink, blue and green
the surface of Tilux products could be either matte or glossy

Companies that manufactured Tilux marble finish wall panel:

CertainTeed Corporation
Flintkote Company

How to Identify Asbestos in Electrical Equipment

Due to its famous resistance to heat and electricity, asbestos was a natural choice which is why manufacturers often used asbestos plastics by default for many electrical components. During the 1940s up until 1980, asbestos was used widely to help insulate electrical wires and prevent deadly fires.

Thick electrical cables were also wrapped in asbestos paper or cloth. This normally includes asbestos impregnated in some sort of textile, then wrapped or braided around the wire or cable, sometimes with a second textile wrapped around it for added durability.

Popular asbestos-containing electrical panel and wire insulation manufacturers include:

How to Identify Asbestos Siding

Many old houses have asbestos siding on their exteriors. Asbestos siding was a very popular product back in the 1950s and 1960s where siding shingles were traditionally made by mixing asbestos into the cement in order to fireproof and strengthen siding. Asbestos siding is very fragile in nature; if a tree branch falls on it, it might crack the asbestos siding panel, and it is going to be hard to find a new siding piece to replace it.

Asbestos siding has some characteristics to look for:

Asbestos siding shingles are usually 12’’ x 24’’
It may behave grooves or wood-grain patterns pressed into the cement, or they may be smooth
Each tile has two or three nail holes at the bottom of each shingle

You can inspect the siding to determine if there is manufacturer information printed on it. Companies that manufactured asbestos siding:

How to Identify Asbestos in Seals and Sealants

Until the 1980s, caulk benefited from the weatherproof and insulating strengths of asbestos. Using asbestos in window glazing and caulking to seal windows and glass panels was common at that time.

If you are not sure that your home has old caulking with asbestos or remnants of it around windows and doors, play it safe and assume that it does.

Manufacturers of asbestos seals and sealants:

Sherwin-Williams Paint Company
Quigley Company, Inc.
Minnesota Mining and Manufacturing Company
Proko Industries, Inc.
CertainTeed Corporation
Combustion Engineering, Inc.

How to Identify Asbestos in Heating Ducts

In older homes, it is common to find asbestos in heating ducts on the interior and exterior surfaces, especially around bends and connections. For example, asbestos duct dampeners – asbestos-containing woven material – that was used to create flexible joins between heating ducts or between an air handler and ductwork.

If you come across ductwork in your property and know that it was installed pre-1970, then the best practice is to assume that it may contain asbestos. In older homes asbestos paper-like material was often wrapped around the entire duct exterior rather than simply at the joints.

Manufacturers of asbestos-containing heating ducts:

More on how to spot asbestos in heating ducts

How to Identify Transite Asbestos Flues

Transit asbestos was a common product used to vent gas appliances such as chimneys, boilers, and water heaters in homes built before 1980. Since there were no other look-alike products that were not asbestos, many asbestos-containing building products are visually obvious and easy to recognize. Asbestos transite pipe heating flue vents may only be noticed by a building inspection. When deteriorated, transite pipe heating flue vents became swollen, causing blockages that in turn cause exhaust gases, along with asbestos fibers, to vent back into the home.

Manufacturers of transite asbestos flues include:

How to Identify Asbestos in Eaves

Eaves are the part of a roof that meets or overhangs the walls of a building. Prior to the mid-80s, eaves were made of asbestos fiber cement sheeting otherwise known as fibro. Over time, asbestos eaves can show signs of deterioration like discoloration, cracking, and splitting.

Manufacturers of asbestos cement eaves:

Amchem, Inc.
Benjamin Foster Co.
Armstrong Contracting and Supply (AC&S)
Baltimore Land Ennis
(G. W.) Berkheimer Company, Inc.
Barrett Roofing Company
Bird and Son
CertainTeed Corporation
Combustion Engineering, Inc.
Flintkote Company
Certainteed Corp.
Armstrong Contracting and Supply Corporation (AC&S)
Capco Pipe Company
Combustion Engineering, Inc.
Synkoloid Company

How to Identify Asbestos in Joint Compounds

A joint compound is a substance used in building construction and renovation similar to plaster used to seam seams between sheets of drywall. Modern drywall compounds do not contain asbestos.

If drywall or gypsum board was installed in your home between the late 1930s and 1980 it is possible to contain asbestos - at least in finishes, taping joint compounds, skim coats, or in systems that applied plaster over gypsum board.

Asbestos-containing joint compounds manufacturers:

How to Identify Asbestos in Carpet Underlay

It has been ascertained that the carpet underlay which is usually a black bituminous material, was commonly used at the height of the asbestos manufacturing period, between 1940 to the 1970s.

When it is time to replace your antique carpet and you think it may fall on the right date (the 1940s to 1980s), then take the proper precautions to avoid risking your health or the health of your family.

Companies that manufactured asbestos-containing carpet underlay: