In Internet language, "lurking" is frequenting Web sites, sometimes even leaving anonymous postings, and hovering around an online community without coming forward and letting everyone know you're there or who you are. Asbestos acts the same way. It lies hidden, persists in hanging around in a house, but doesn't announce itself. Responses to both types of lurkers range from annoyance to outrage to fear to "who cares?" Living peaceably with a virtual lurker is one thing, but what about living with asbestos? In most cases, it's probably best to actually leave asbestos alone, but once it starts intruding on your health and safety, it's time to call in a professional.
Beginning in the late 1970s and continuing through the late 1990s, asbestos products in the United States were banned and phased out, but any that were used before the bans went into effect remain in place [sources: CPSC, Howard University]. Asbestos has links to diseases ranging from mesothelioma and lung cancer to asbestosis -- all serious and often deadly diseases -- so recognizing where it remains and when it needs to be dealt with is important [source: EPA].
Although asbestos occurs naturally in mineral form and is a strong, heat-resistant fiber, it's also a tiny and potentially deadly component used to strengthen man-made materials. These asbestos containing materials are called ACMs. At a size "700 times smaller than human hair," an asbestos fiber isn't something you can see on your own or detect by poking around for it -- and overwhelmingly, the advice is don't go poking around for it, because breaking up an ACM will release the toxic particles [source: Princeton University].
How then can you find where or whether it's lurking about, and how should you treat it? Let's look at some common asbestos hide-outs in the home.
Using asbestos-containing products for caulking around doors and windows was common until the 1970s, when using asbestos in building materials was banned in the United States. Caulk benefited from the weatherproof and insulating strengths of asbestos, but it poses health risks when worn, flaking or being replaced. Older homes might have old caulking with asbestos or remnants of it around windows and doors, though homes from the past 20 years likely do not [source: Howard University].
Until the asbestos bans, using asbestos products to improve gasket seals on furnace doors, such as those on old coal chutes, for example, also was common due to their heat resistance and ability to form and hold a tight pressure seal [source: CPSC, et. al]. Removing or cleaning old oil or coal furnace doors or making structural improvements around them can release particle chips from these dried seals, releasing asbestos dust.
If buying or renting an older home with decades-old caulking or basement coal chutes and stoves, enlist the services of a professional to check for asbestos before replacing or removing any parts.
Picturing something fried is one way to understand terms related to asbestos in roofing and siding. Fried foods or burnt materials are dry, crumbly or crispy and rough around the edges. They are usually easy to break up or apart. Something "nonfriable" is not easy to break down because its fibers are strong and tightly held together. A nonfriable material can become "friable" with wear and tear, though, and can come apart with applied pressure [sources: Merriam-Webster, MDH].
Most cement or asphalt composites used in roofing and siding are generally considered nonfriable, but those with a large paper make up are friable because they come apart with pressure. Both types release breathable particles of asbestos when cut into or removed by tearing and pose a health hazard [source: MDH].
Checking materials for asbestos is sometimes just a matter of looking for markings or product numbers and researching. With care and help from trained professionals, siding and roofing with asbestos products can be removed or covered, but they typically pose a low risk if intact and left alone [source: Woods].
While metal pipes and ductwork are great heat carriers, additional outer wraps or treated coatings help keep more heat en route to the vents where air comes out to heat rooms. Adhesives also block air from escaping from seams where air flow systems are joined to the furnace or to more lengths of ductwork. As with gaskets and caulking, products with asbestos were common when reinforcing ducts and pipes because they'd contain the heat without deteriorating under the high temperatures [source: CPSC].
Old systems of steam piping and even some hot water plumbing are wrapped in asbestos-containing "blankets" that pose serious risk when removed or cut without the help of a professional who uses protective measures to damper the release of particles. Any systems in older homes, even if they appear intact, can be evaluated for cracks or deterioration by a trained asbestos inspector. Disturbing the materials or self-testing is not advisable. If wear is found, ductwork and piping may be covered, or encapsulated, and sealed in [source: EPA].
Many public and commercial buildings -- from classrooms and hospitals to offices and stores -- have asbestos ceiling tiles. They were a practical choice for fire resistance and insulation properties, and their popularity spread to housing construction. Banning asbestos started in the 1970s, but experts agree that it is likely part of many homes built before 1981 [source: Goodwin].
Obvious forms of asbestos ceiling tiles are the 9 by 9 inch (22.86 by 22.86 cm) or 12 by 12 inch (30.48 by 30.48 cm) white or off-white panels held up in a grid system. Adding or removing a tile involves pushing it up from the grid frame and angling it down and out or up and in place. Basements in homes, in particular, might feature the tiles because of their soundproof qualities and low cost. It's estimated that 5 to 10 percent of the ceiling tiles in the U.S. contain asbestos [source: EPA].
Ceiling tiles made with asbestos are a lower risk because the asbestos fibers are tightly woven within the tile. As with other asbestos materials, however, removing, breaking or cutting can release harmful particles from the fibers. When left in place, tiles can remain as is or be treated with sealant to protect them from wear or breakdown [source: Asbestos.com].
Many people who have looked to buy or rent an older home have ruled out choices because of ugly wall coverings. Removing layers of old paper that have hung in there, adhering to walls for decades, is a remodeling project of major proportions. It involves lots of time and elbow grease. In homes papered before 1980, it can even be downright dangerous to undertake wallpaper removal because many vinyl papers before that time contain asbestos [source: EPA].
If intact, wallpaper may be best left alone, but if there are signs of cracking and curling, a professional can test the paper and adhesive behind the paper for asbestos and recommend options for removal or remediation. Sealing the walls with paint and other coatings will prevent deterioration of the paper and keep any particles from releasing into the air even with breakdown. Often it is best to just paint over it but it's still advisable to get professional advice on which products work best to contain the mess.
Asbestos is naturally very heat resistant and nonflammable, so it was a great choice for protecting surfaces around furnaces and wood burning stoves. Dense papers, thick boards and sheets of special cement all composed with asbestos fiber are prevalent in U.S. homes built before about 1980, and asbestos-containing disks for covering stovetop heat elements also abound [source: Princeton University].
Upgrading stoves and heating systems in any way that involves removing or disturbing the fireproofing surrounding the units themselves should involve the help of a trained asbestos expert. While these surrounds were designed to protect the walls and floors from heat damage, they are now some of the more dangerous asbestos sources to humans if broken down without protective measures. Often, homeowners decide to live with the outdated and sometimes funky looking old heat stoves and furnaces in order to avoid the release of asbestos from the surrounding materials, and generally, just leaving them alone is a safe way to keep the asbestos contained.
Similar to wall coverings and ceiling tiles, floor coverings made with asbestos have very tight fibers. Vinyl sheet, rubber and even some asphalt flooring can be made with asbestos, and even the adhesives used to secure them to the subfloor might include a compound made with asbestos. According to the EPA, you can assume that floor tiles installed before 1981 contain at least some asbestos [source: EPA].
Flooring with asbestos generally has a low percentage of it and can be covered up safely [source: Princeton University]. However, whether in sheets, tiles or poured form, it should be evaluated by a trained asbestos specialist if it is cut or cracked -- especially if there is the presence of dust from any broken areas of the floor. And even if the floor appears to be intact, any construction or remodeling projects, or the removal of building elements that meet with the floor, such as a furnace or wall baseboards and trim, can dislodge particles from the adhesive or flooring itself around cut or disturbed edges. Call a professional before starting work to ensure you won't release any old particles.
Sandpaper is a seemingly harmless and very helpful tool in smoothing surfaces and adding finishing touches to the interior of a home, but in some cases, it releases invisible and damaging particles into the air and onto household surfaces. Joint compounds, putties and cement patching products manufactured before 1981 are common sources for asbestos [source: EPA]. With its strength and tight fibers, asbestos was a highly effective mineral for improving the binding and covering properties of materials used in joining sections of wall, ceiling and floor, as well as for smoothing out sections of rough walls or patching holes.
When left alone or covered properly, this asbestos is safe and contained, but something as cosmetic as sanding or as major as structural shifting (over time or due to rehab or earthquakes, for example) can lead to cracks and particle exposure. If you're considering home repair and improvement on homes from the decades before the mid-1980s, an inspector can perform sample tests to detect asbestos that might lie beneath the surface.
A major use for asbestos over the years was for insulating. Walls were filled with asbestos insulation to block noise in multi-unit housing and apartments and to contain warmth in single-family dwellings. Attic insulation often used a product with vermiculite ore, which proved to have natural veins of asbestos running through it. And even water pipes were better insulated with concrete compounds strengthened by asbestos. Houses built between 1930 and 1950 are highly likely to have one or all of these forms of asbestos insulation, and even houses up through 1990 may have some vermiculite [source: EPA].
Asbestos-containing insulation can be coated, or encapsulated, or even wrapped in protective coverings to seal it from potential deterioration, or it can be removed, depending on the recommendations of asbestos experts [source: EPA]. Any cracked piping or crumbling spots of a wall or attic should be tested for asbestos, but as with other areas, it is best left alone altogether until assessed by professional.
Although textured paint and molding compounds were included in the bans on asbestos products, walls and ceilings all across the U.S. bear evidence to their popularity before then [source: EPA]. Popcorn walls and swirly-icing-like ceiling confections are -- depending on personal taste -- usually fairly ugly but also very common. Asbestos treatments were sprayed on walls and ceilings as an inexpensive and easy decorative overlay, and they often covered up underlying problems before the dangers of asbestos itself were discovered. Layers of thick and bumpy adhesives and paints also dampened noise, and this thick treatment has led many homeowners to just paint over rather than engage in full-scale wall demolition. Choosing to remove or sand down the surfaces would lead to the release of asbestos on a wide scale and should not be entered into at all without professional help and planning.
If you love the home but don't have the funds for a safe and potentially costly remodel, you may have to just embrace the ugly to keep the even uglier asbestos contained.
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More Great Links
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- Goodwin, Carl. "Asbestos Awareness Training." North Carolina Office of State Personnel. March 29, 2000. (April 15, 2011)http://www.osp.state.nc.us/emprsk/asbestos/topic2.html
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- International Association of Certified Home Inspectors, Inc. (InterNACHI). "International Standards of Practice for Inspecting Residential Properties." Nachi.org. 2011. (April 19, 2011)http://www.nachi.org/sop.htm
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- Mesothelioma & Asbestos Awareness Center. "Vinyl Wallpaper." Dec. 28, 2010. (April 15, 2011)http://www.maacenter.org/asbestos/products/vinylwallpaper.php
- Minnesota Department of Health (MDH). "Asbestos: Homeowner Information, Roofing and Siding." 2011. (April 15, 2011)http://www.health.state.mn.us/divs/eh/asbestos/homeowner/roofside.html
- MSN Real Estate. "Disclosure: What Sellers Need to Know." 2011. (April 19, 2011)http://realestate.msn.com/article.aspx?cp-documentid=13108441
- Princeton University. "Asbestos Fact Sheet." Princeton.edu, Environmental Health and Safety (EHS). April 13, 2006. (April 15, 2011)http://web.princeton.edu/sites/ehs/workplacesafety/asbestosfactsheet.htm
- United States Environmental Protection Agency (EPA). "Asbestos." EPA.gov. June 18, 2010. (April 16, 2011)http://www.epa.gov/asbestos/
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- United States Environmental Protection Agency (EPA). "Asbestos in Your Home." June 7, 2010. (April 15, 2011)http://www.epa.gov/asbestos/pubs/ashome.html
- United States Environmental Protection Agency (EPA). "Asbestos NESHAP Adequately Wet Guidance." Dec. 1990. (April 16, 2011)http://www.epa.gov/region4/air/asbestos/awet.htm
- Woods, Amy Lamb. "Keeping a Lid on It: Asbestos-Cement Building Materials." Technical Preservation Services, NPS.gov. Aug. 2000. (April 15, 2011)http://www.cr.nps.gov/hps/tps/recentpast/asbestosarticle.htm