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Here is our photo guide and text that can help in identification of asbestos-containing wall siding products like asphalt shingles & asbestos-cement siding shingles. This document assists building buyers, owners or inspectors who need to identify asbestos materials (or probable-asbestos) in buildings by simple visual inspection. In the website sections listed below, we provide photographs and descriptive text of asbestos insulation and other asbestos-containing products to permit identification of definite, probable, or possible asbestos materials in buildings. Also see other cementious siding materials such as JamesHardie HardiPlank Siding and cementious roofing materials such as Cement-asbestos roof shingles and Corrugated Cement-Asbestos Roofing.

While an expert lab test using polarized light microscopy may be needed to identify the specific type of asbestos fiber, or to identify the presence of asbestos in air or dust samples, many asbestos-containing building products not only are obvious and easy to recognize, but since there were not other look-alike products that were not asbestos, a visual identification of this material can be virtually a certainty in many cases.

Photo Guide to Cement-asbestos Wall Shingles or Siding Products

Is it safe to buy a home with cement asbestos siding? Most cementious building materials are considered to be non-friable, and are probably less hazardous than other friable asbestos products such as asbestos pipe insulation. However removal of asbestos-containing roofing products is regulated as we discuss at OSHA Regs.

How can we tell the difference between asbestos-containing shingles and fiber-cement wall shingles?

It's tricky. But here are some ways to distinguish between asbestos containing shingles and non-asbestos fiber-cement shingles:

• Age or date of installation: installed before 1978 the shingles probably contain asbestos.

If an asbestos-cement sided home has been re-modeled such as by adding a window or door, it's likely that the old asbestos cement shingles were broken around that new opening during the construction work - expect to see newer fiber cement shingles there.

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• Asbestos products and their history and use in various building materials such as asphalt and vinyl flooring includes discussion which draws on Asbestos, Its Industrial Applications, D.V. Rosato, engineering consultant, Newton, MA, Reinhold Publishing, 1959 Library of Congress Catalog Card No.: 59-12535 (out of print).
• "Handling Asbestos-Containing roofing material - an update", Carl Good, NRCA Associate Executive Director, Professional Roofing, February 1992, p. 38-43
• EPA Guidance for Controlling Asbestos-Containing Materials in Buildings, NIAST, National Institute on Abatement Sciences & Technology, [republishing EPA public documents] 1985 ed., Exposure Evaluation Division, Office of Toxic Substances, Office of Pesticides and Toxic Substances, U.S. Environmental Protection Agency, Washington,D.C. 20460
• "Asbestos in the Home," U.S. EPA, Exposure Evaluation Division, Office of Toxic Substances, Office of Pesticides and Toxic Substances, U.S. Environmental Protection Agency, Washington,D.C. 20460
• NRCA Roofing and Waterproofing Manual, 4th Ed., available from the National Roofing Contractors' Association.
• "Tips for working with fiber-cement roofing products", Thomas L. Smith, AIA, RRC, Professional Roofing, September 1996

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Maintenance & Repair Tips for Asbestos Cement Wall Siding Shingles

We consider asbestos cement wall shingles a durable and fire-resistant roof and an asset to the building provided that the siding is in good condition. But because the material is easily damaged by a heavy-handed worker unfamiliar with the materials involved, asbestos cement siding has to be repaired and maintained with care.

Replacement cementious wall shingle materials are now available that look almost exactly like the original materials, but that do not contain asbestos. That's the product we have used to repair the building shown in the photographs in this article.

Small temporary wall siding repairs to individual shingles can be made using copper or aluminum flashing material -- it can be painted color that looks alot like the remaining cement asbestos shingles, and this approach minimizes the chances of breaking more shingles during the repair.

How to Remove and Replace Broken Asbestos Cement Wall Shingles

What about replacing the siding?  Can you side over the existing asbestos cement siding or does it need to be removed? First let's discuss replacing individual broken sections of fiber cement siding:

It is very difficult to remove individual broken asbestos-cement wall shingles, but working carefully it can be done.

Work by an inexperienced contractor can ruin a cement asbestos shingle wall siding and lead to complete replacement that could have been avoidable.

• Use vise-grips or a pair of horse-shoe nail clips or similar tool to carefully pull out the nails from the intact, un-damaged cement-asbestos shingles above and around the damaged shingles. Pull nails carefully so as not to break the intact shingles. Do not try to pry up asbestos cement shingles - they are brittle and will break.
• Slide out the damaged asbestos cement wall shingles
• Inspect the wall sheathing for leak or water or insect damage that may need repair
• Install a house-wrap or roofing felt over any exposed wall sheathing, sliding its upper edge under the older materials so that any water that penetrates the wall will be directed out not into the wall cavity.
• Carefully slide the new fiber cement shingles into place. If cement-shingles have to be cut, use the manufacturer's recommended cutting tool, not a power saw that will make a lot of dust.
• Line up the nail holes between the old (upper layer) cement asbestos shingles and the new fiber cement shingles to be secured underneath. They wont' line up, right? OK so use a tiny masonry bit and drill through the existing hole in the old asbestos cement (intact) shingle and through the new fiber cement shingle below.
• Nail the new shingles in place, carefully - don't let your final hammer strokes drive the nail so hard against the fiber cement shingle or asbestos-cement shingle that you break it.

Siding over asbestos cement siding:

A common remodeling practice is to install new vinyl or aluminum siding over cement asbestos shingle siding as well as over many other older siding materials when the old siding has become damaged, leaky, or cosmetically ugly. A typical procedure is to install furring strips on the existing wall, avoiding breaking the existing siding. The new siding is then secured to the furring strips so that the new wall siding will be smooth and flat.

Additional steps may be needed to build out window and door trim for aesthetic reasons - so that the windows and doors do not appear to "recede" into the walls of the structure.

Sources of Replacements for Asbestos Cement Wall Shingles

One manufacturer of cement-asbestos shingles was Ruberoid Co., who made 8" x 16" tapered singles with a surface pattern resembling wood and called "Ru-Ber-Oid-Eternit Tapered Timbertex Asbestos-Cement Shingles." 260 singles/525 lbs/square, were available in a wide range of colors.

Contemporary cement asbestos product manufacturers make reinforced fiber-cement wall and roofing shingles and other products which look like, perform similarly to, and need to be installed similarly to the original asbestos-cement shingles - but these new products are free of asbestos. The replacements for asbestos cement wall siding products are reinforced with a variety of fibers including fiberglass. Other replacements for asbestos-cement siding use both different fibers and a different aggregate (perlite) to replace the asbestos. Some of the substitute products have been in use for more than 30 years (2008).

For maintenance or replacement of asbestos-cement wall siding or roof shingles (or wall siding) contact Supradur Manufacturing Corporation, PO Box 908, Rye NY 10580 800-223-1948, or from within New York State, call 914-967-8230. Ask about their Supradur(R) mineral fiber shingles.

For handling and disposal guidance concerning old cement-asbestos wall siding material contact the US EPA, your state Department of Environmental Protection/Conservation, or your local building and health departments.

Painting Cement Asbestos Building Siding

Should I paint my asbestos cement shingles? Do you need to use special paint for cement asbestos siding?

Painting cement asbestos siding or non-asbestos fiber cement siding is mostly a cosmetic decision. We have never seen this material in a worn, friable condition, but should that occur, one might paint the surface also to stop fiber shedding and to preserve the material.

Fiber cement shingles, both new non-asbestos product and the older asbestos-cement product are provided from the manufacturer with a coated surface, usually white. When the asbestos cement siding is soiled or moldy or has an algae coating we prefer to gently clean the surface with a sprayer, perhaps a deck cleaner solution. If you use a power washer be careful to spray "down" (to avoid blowing water into the building walls) and to keep far enough away that you do not damage the siding or "rough it up" which may cause more rapid deterioration or even fiber or asbestos release.

But sometimes the asbestos cement or fiber cement shingles just look soiled and do not clean up enough to satisfy the homeowner. In general, this siding material can be painted using normal house paints. Check with your paint suppliers because some paints may not be recommended for the surface. But once you paint the siding, you've converted a "no maintenance" surface into one that will occasionally need to be re-painted for cosmetic reasons.

OSHA Regulation of roof demolition where asbestos containing roofing materials ACRM are present may also pertain to wall siding demolition

Beginning in 1986 OSHA set a permissible exposure limit (PEL) of 0.2 fibers per cubic centimeter (f/cc) of air over an 8-hour time-weighted average exposure period. OSHA also set an action level of 0.1 f/cc of asbestos for an 8-hour TWA average, and (the highest permitted short term asbestos fiber exposure) 1.0 f/cc "excursion limit" for a 30-minute time period. According to NRCA, the National Roofing Contractors' Association, their studies up to February 1992 had not found a single roofing job at which these limits were exceeded, and NRCA reported that in some cases no fiber release was detected.

We note that the association would have been referring only to asphalt-based roofing materials, not jobs involving the demolition of other ACRM such as cement-asbestos roof shingles (or "asbestos roof tiles" as some consumers refer to them) which might produce different statistics.

© Copyright 2009 Daniel Friedman, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use links at the left of each page to navigate this document or to view other topics at this website. Green links show where you are in our document or website.

More Information on Building Diagnostic Inspections and Repairs

• Asbestos: How to find and recognize asbestos in Buildings - visual inspection methods, list of common asbestos-containing materials
• Asbestos HVAC Ducts and Flues field identification photos and guide
• Fiberglass: Indoor Air Quality Investigations: Health Concerns About Airborne Fiberglass: Fiberglass in Indoor Air from HVAC ducts, and Building Insulation
• Enviro-Scare: Electric Power Lines, Electromagnetic Fields, Cancer Risk, & "Enviro-Scare" - The Normal Curve Cycle of Public Fear of Environmental Issues
• Dust from the World Trade Center collapse following the 9/11/01 attack: the lower floors of this building contained spray-on fire-proofing asbestos materials.
• Asbestos Information Links: Asbestos Detection, Testing, Recognition, Hazards, Field Photos, and Information Sources, including health-related links such as legal services and information about mesothelioma and other cancers.
• Asbestos Identification and Testing References
• Asbestos Identification, Walter C.McCrone, McCrone Research Institute, Chicago, IL.1987 ISBN 0-904962-11-3. Dr. McCrone literally "wrote the book" on asbestos identification procedures which formed the basis for current work by asbestos identification laboratories.
• Stanton, .F., et al., National Bureau of Standards Special Publication 506: 143-151
• Pott, F., Staub-Reinhalf Luft 38, 486-490 (1978) cited by McCrone

For more information about fiberglass as an indoor air quality concern see:

• Fiberglass in Indoor Air, HVAC Ducts, and Building Insulation
• Fiberglass Particle Identification in the Fiberglass Test Laboratory
• Goodman Gray Flex Duct Deterioration and Failures
• Mold in Fiberglass Insulation
• Optimum Indoor Air Filters
• Owens Corning Flex Duct Deterioration and Failures
• World Trade Center Dust Particle Identification

For more information about asbestos as an indoor air quality concern with focus on easy ways to identify asbestos materials in buildings, see:

• Asbestos Identification in Buildings: How to find & identify asbestos-containing materials
• Asbestos in Good Condition
• Asbestos HVAC Ducts - Asbestos Materials On or In Heating and Cooling Duct Work
• Asbestos paper duct wrap
• Asbestos Transite Chimneys, Flues, & Pipes in Buildings
• Asbestos under the microscope
• Asbestos Vibration Dampers & Asbestos in the Air Handler
• Ceiling tiles: How to recognize ceiling tiles that may contain asbestos
• Examples of unusual uses of asbestos in buildings

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