Asbestos was a popular industrial material for most of the twentieth century, used because of its ability to insulate and act as a fire retardant. It is still used in some parts of the world such as India and China. We know enough about the risks now, though, that it is banned in more than 50 countries and for most uses in the U.S.
Asbestos in the home
One of the places you might find asbestos in a home is the ductwork, although you don't really know without sending a sample to a lab. A qualified inspector can tell you he or she suspects asbestos but only a qualified laboratory can tell you for sure. If you live in an older home and have rigid ductwork that has an off white or yellowish fabric like coating or covering, there is a chance it’s asbestos.
What health problems does asbestos cause?
The big three diseases listed on all the asbestos websites are:
Asbestosis is an inflammation leading to shortness of breath, coughing, and other breathing problems. Mesothelioma is a cancer of the protective membrane around the lungs. Lung cancer is well known because so many people succumb to it each year.
The World Health Organization says asbestos exposure leads to these three diseases killing more than 107,000 people worldwide every year. That's a big number. In addition, many more people die of other asbestos-related diseases or suffer various levels of disability.
The problems with asbestos have been known for a long time. The ancient Persians and Romans used the stuff and may have noticed health problems associated with its use. In 1902, asbestos was added to a list of harmful industrial substances in England. Nellie Kershaw, who worked in a factory spinning asbestos fibers into fabric, was the first officially diagnosed case of asbestosis. She died in 1924. You can find information about her on Wikipedia.
The consensus in the medical community is that asbestos is dangerous, which is why it's classified as a known human carcinogen. There's no debate on that point, and the lawyers have had a field day litigating asbestos health problems.
What should you do about asbestos in the home?
If you do find something in your home that you think may contain asbestos, there are two rules: Don't mess with it! Don’t panic!
If you see a coating on your ductwork that you suspect may be asbestos, it's probably not causing a problem if it's undisturbed. Asbestos only becomes a problem if it becomes airborne and gets into your lungs at a high enough dose.
More about asbestos ductwork.
There are no laws or building codes that require homeowners to remove asbestos containing materials from their homes. As for the health risks to your family, that depends upon the type, location, and condition of the material.
From the mid-1950's through the early ’70's, sheet metal air ducts for forced-air heating systems were commonly insulated with a fabric like material that contained asbestos fibers. Similar in appearance were other ducts that were made entirely of this asbestos containing material (ACM). In some cases, close examination is necessary to determine whether these old ducts are composed of asbestos or merely insulated with it.
The material itself is not regarded as a significant health hazard if it is undamaged, securely attached, and not exposed to routine contact. In such cases, the accepted advice is simply to leave it alone. Remember asbestos must be air borne and in heavy concentrations to cause health problems.
When metal ducts are wrapped with asbestos insulation, the ACM is on the outer surfaces, not exposed to the air stream within the ducts, providing little or no opportunity for contamination of the circulating air. If the material is intact, it should be left as is. If it becomes loose, detached, or physically damaged, patching or removal should be handled with extreme care. In some cases, if the damage is not extensive repairs can be made using tape or painting the area to prevent any of the fibers from becoming air borne. Approved respirators should always be worn.
Ducts that consist of ACM are not common, but they do exist in some homes. The interior surfaces of these ducts are covered with metal foil, preventing direct contact of the air stream with the asbestos material. However, if the ducts become punctured or torn, asbestos fibers can be released into the air stream. In that case, repair or removal by a qualified contractor. Removal of the ductwork by a qualified contractor generally entails isolating the area with poly or plastic sheeting to contain any dust or asbestos fibers, wetting the ductwork to contain any fibers, and dismantling and wrapping it with poly or plastic and taking it to the land fill.
For a comprehensive evaluation of your air ducts to determine their level of safety and functionality, it is recommended that you consult a certified, inspector. Expect him to recommend sending samples to an accredited laboratory.
Asbestos siding was very commonly used in buildings and homes from around the 1920s until the 1980's and can still be found in many older homes in the U.S. and Canada. Asbestos siding was made by adding asbestos, a naturally occurring mineral, to Portland cement. That cement was then pressed into siding shingles that came in a wide variety of sizes, profiles, and textures. They are very durable, fire-resistant, and absorb paint well.
As with any asbestos product the problem comes when the shingles are broken, cut, or crushed, and the asbestos particles are released into the air and inhaled. The other factor to keep in mind is the only way to determine whether the siding contains asbestos is to have a sample analyzed by a laboratory. Some home inspectors can give you an educated guess as to whether the siding contains asbestos, but it will be just a guess.
The presence of asbestos cement siding should not necessarily be viewed as a serious problem. There are hundreds of thousands of homes and garages with this siding material, and when it is in good shape, the health hazards are minimal.
The presence of asbestos-cement siding, in and of itself, is not a serious drawback. The National Association of Certified Home Inspectors notes the following advantages and disadvantages of asbestos-cement siding:
· Asbestos cement siding is highly fire-resistant and will not burn or melt the way vinyl and wood siding will.
· It resists termite damage.
· It resists rotting.
· It has been manufactured with textures intended to simulate the look of other cladding materials, such as wood grain.
· It is easy to clean and maintain.
· Unlike more porous siding materials, such as wood clapboard, asbestos cement siding will not quickly soak up paint, which allows it to be painted more easily.
· Asbestos cement siding is very brittle and can be easily chipped, cracked or broken.
· The use of a pressure washer for maintenance can crack the siding and lead to moisture intrusion, if the pressure setting is high enough.
· Asbestos cement can be dangerous if pulverized by sawing, sanding, breaking, etc.
· It is difficult to find replacement siding for repairs.
· This product cannot be refurbished, unlike other forms of siding. Wood clapboard, for example, can be sanded and re-painted, and cedar shake siding can be sand-blasted and re-stained. Either of these methods can restore wood close to its original state. But this is not possible with asbestos-cement siding.
· It is no longer considered aesthetically desirable.
Why removal should be avoided
Despite some inherent advantages to asbestos-cement siding, and despite the inherent dangers of disturbing it through removal, some homeowners insist on removing it. But this should be carefully considered. A better strategy may be to cover it over with new siding, which effectively seals in the asbestos material. This is usually the preferred method of dealing with asbestos building materials. Most siding companies are well-experienced at techniques for covering over existing asbestos-cement siding with new vinyl, aluminum, or a newer form of fiber-cement siding. If a siding company removes an outer layer of siding and finds an older layer of asbestos-cement siding beneath, the standard procedure is simply to cover it over with new siding rather than remove it.
Removing the asbestos-cement siding, in addition to the health hazards involved, only adds more work to your project and will cost that much more. Removing asbestos cement siding may not be a simple matter of calling up a local contractor. Depending on where you live you may need to obtain special permits and have a special asbestos remediation company perform the work. Such work can be done by a homeowner, but special procedures and disposal methods must be followed.
A home that has enclosed the old asbestos-cement siding with new siding is perfectly acceptable to home inspectors and real estate assessors, and it rarely has any negative effect on home values.
What if you find asbestos in your home? Do not panic if asbestos is found or suspected in your home. Just because your home has materials that contain
asbestos does not mean your health is in danger. If the ACM is in good condition, leave it alone and do not disturb.
Leaving ACMs alone is the least costly option.
Consider educating children living in the home about the danger of asbestos. Some helpful tips follow:
• Leave undamaged ACMs alone.
• Limit children’s access to suspected ACMs.
• Employ services of trained and licensed handlers.
• Avoid disturbing suspect ACMs.
• Do not vacuum, dust or sweep damaged ACMs.
• Do not grind, crush, pulverize or use power tools on suspected ACMs.
• Wet ACMs and wrap in plastic, if you have to transport them through the house.
My goal is to have a series of articles that deal with items that may be found on the home inspection report. There will also be articles on choosing a home inspector and a realtor. This information will be based on my experience in the construction industry as well as information I research. I welcome your comments. If you have a question or would like to see an article on a particular subject please ask.