How to Safeguard Your Home from the Risk of Asbestos
Most people are aware that the use of asbestos in home construction has been banned in Canada due to the serious health risks it poses. But when it comes to our homes, how can we know whether asbestos is present and how to safeguard against it? This article highlights some pertinent information about asbestos that you should know for your peace of mind and planning. It discusses where asbestos can be found in the home and what to do about it.
Asbestos was widely used
The word asbestos means “inextinguishable” in Greek. It has been used since antiquity in a wide range of products such as lamp wicks, funeral shrouds, and ceremonial tablecloths, which the ancient Greeks would throw into the fire to clean.
Asbestos is a naturally occurring mineral composed of long, thin, silky strands of fibrous material that are strong and durable. It binds easily with other materials, making it an ideal reinforcement material in construction. The unique properties of sound absorption, non-combustibility, tensile strength, and resistance to electrical and chemical damage made asbestos a popular choice among manufacturers and builders from the late nineteenth century.
In the 1800s, asbestos was a major component in the machinery that powered the industrial revolution — hot engines, boilers, and piping. In World War II, it was widely used in the shipbuilding industry. In the 1900s, asbestos layered the walls and ceilings of public buildings and homes to insulate against fire and sound.
Health risks of asbestos
Although concerns about the health risks of exposure to asbestos were recognized from the late 1800s, public awareness catapulted in the 1960s when it was found that heavy, prolonged exposure to asbestos led to an increased incidence of lung disease in workers. When asbestos fibers are inhaled, they stay lodged in the lungs for years, predisposing a person to the following diseases:
- Lung cancer
- Asbestosis — scarring of the lungs with fibrous tissue
- Mesothelioma — cancer of the lining of the chest and abdominal cavity
Asbestos has been largely banned from commercial and residential construction in most of the developed world. Tragically though, it is still being mined in a small number of countries, including Canada until late in 2011, and exported to developing nations such as India and China, where it continues to ravage vulnerable workers. The World Health Organization reports that about 125 million workers worldwide are exposed to asbestos and at least 90,000 die each year from asbestos-related diseases.
Where is asbestos found in the home?
There is a strong likelihood that pre-1978 homes contain asbestos, especially in siding, floor tiles, and wall and ceiling insulation.
Asbestos is added to many products to enhance strength, and most asbestos in homes is found in asbestos-containing building materials (ACM). There are three main categories of ACM use:
- Surfacing — sprayed or troweled on surfaces for acoustical, decorative, or fireproofing purposes. Includes wallboard, plaster, textured and latex paints, and fireproofing insulation.
- Thermal system insulation — for example, furnace duct tape; insulation used to inhibit heat transfer on pipes, boilers, tanks, ducts, and other components of water systems, heating ventilation systems, and air conditioning (HVAC) systems; and in loose-fill vermiculite insulation.
- Miscellaneous — other products and materials such as resilient floor tiles (vinyl, asphalt and rubber), ceiling tiles; carpet underlays; roofing clapboard, felt and shingles; patching and spackling compounds; cements; concrete pipe; and exterior siding.
When is asbestos a problem?
When considering whether asbestos in the home may be a problem, it is important to distinguish between friable and non-friable. Friable refers to material that can be crumbled or reduced to powder by hand pressure, and can become airborne on touch. Examples include damaged pipe insulation or sprayed-on ceiling material. Non-friable refers to everything else. Although friable material releases asbestos fibers into the air more readily, non-friable materials can also release fibers if disturbed.
If asbestos is tightly bound in a product, it does not pose any risk to health. For example, dense construction materials such as insulation board, asbestos cement, and floor and ceiling tiles do not normally release asbestos fibers. It is only when these products break down through aging or when they are disturbed that problems can ensue.
Homeowners can inadvertently put themselves at risk when they undertake repairs or renovations without being aware that disturbing asbestos-containing materials can release fibers into the air. Even in well-bonded materials, asbestos can become loose and airborne when the materials are cut, scraped, filed, sanded, or removed. Here are some of the ways that fibers can be released into the air:
- sanding or scraping of vinyl floor tile during removal
- repairing or removing appliances that have asbestos insulation around them (e.g., hot water tank)
- cutting, tearing, sanding, drilling, or sawing of insulation
- breaking apart acoustical or decorative material sprayed on walls and ceilings
- sawing, drilling, or cutting of asbestos cement roofing, shingles, and siding; tampering with roofing felt
- disturbing loose-fill vermiculite insulation which may contain asbestos
- sanding or scraping older asbestos coatings such as roofing compounds, spackling, sealants, paint, putty, caulking or drywall, and textured paints
How to minimize asbestos risks
If the product is well contained and not exposed to the interior home environment, it poses very little risk. The best thing to do in this case is to leave it alone.
Unless a product is labelled as containing asbestos, you can’t detect its presence simply by looking at it. If you suspect that a material contains asbestos, and you’re planning on doing something that might disturb it, you should have it sampled and analyzed by a qualified and licensed contractor. It is not recommended that you attempt to take samples yourself. If you disturb the material by hitting or rubbing, asbestos fibers may be released into the indoor air.
Before remodelling or renovating, it’s important to find out whether asbestos-containing materials are present and if they are damaged in any way. If this is the case, and you’re planning to make changes that might disturb it, repair or removal by a professional is probably needed.
Repairing asbestos in your home
This option is usually cheaper than removal, but it may make later removal of asbestos more difficult and costly. Repair involves either covering or sealing the asbestos-containing material to prevent the release of fibers into the air.
- Covering (or enclosure) involves placing something over or around the material. For example, exposed insulated piping can be covered with a protective wrap or jacket.
- Sealing (or encapsulation) involves coating or penetrating the materials to seal in the asbestos. If the materials are soft and crumbly (friable), sealing is not appropriate. Pipes, furnaces, and boilers can sometimes be repaired in this manner.
Removing asbestos from your home
This option involves the stripping of asbestos-containing materials from surfaces or components. It should be considered only as a last resort when the material is damaged beyond repair or the disturbance of material cannot be controlled with appropriate procedures. Removal may be required when you are remodelling and making major structural changes. It is a dangerous, complex, and expensive process that must only be undertaken by a contractor with specialized training and licensing.
- Be informed about the risks of asbestos in your home. If your home was built prior to 1978, be aware that it probably contains asbestos.
- Have sampling done by a qualified professional if you suspect a product may contain asbestos.
- Do not attempt any repairs or renovations yourself on materials that may contain asbestos.
- If the asbestos product is well contained and protected, leave it alone!
- Keep in mind that asbestos should not be disturbed, sampled, removed, or repaired by anyone other than a qualified and licensed professional