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Asbestos cement sheet product production, properties, & uses: this article describes asbestos cement sheet materials including asbestos roofing tiles or shingles, asbestos-cement shingle siding, flat asbestos-cement sheet products such as asbestos millboard and asbestos insulation, and corrugated asbestos sheeting used for both roofing and siding.
Cement asbestos materials: this article series describes asbestos cement products & materials and the history of their production and use. This article includes text & data Adapted from Rosato (1959 out of print) on the production and use of asbestos-containing materials, adding photographs, inspection, repair and maintenance advice, and updates on asbestos hazards involved in the installation, repair, or demolition of asbestos cement products such as roofing and siding or asbestos millboard that remain in place on buildings.
Our page top photograph shows badly broken cement asbestos roofing shingles on a building in upstate New York.
Asbestos is safe and legal to remain in homes or public buildings as long as the asbestos materials are in good condition and the asbestos can not be released into the air. - US EPA
[Click to enlarge any image]
The major production of asbestos-cement materials is in
the form of shingles and sheets. The principal products, in
order of their volume,* are siding shingles, flat sheets,
roofing shingles, and corrugated sheets. Flat sheets and
cor-rugated sheets are utilized for interiors as well as exteriors.
The oldest use of asbestos-cement products involves the
use of fire-proof roofing shingles.
manu-factured are simulated ceramic bathroom tile, facings of
acoustical materials, electrical switchboard panels,
laboratory table tops, electrical conduits, electrical sheets, and
Asbestos-cement sheets are made either in the dry
or wet mixing process.
Manufacture of Asbestos Cement Siding Shingles.
Asbestos-cement siding is being used in
millions of homes, inasmuch as it is both attractive and
'serviceable. Sidings are presently available with improved
weather-resistance and with distinctive surface texture or
color. They have been accepted widely for exterior use in
new homes of all price groups.
* The Asbestos-Cement Products Guide, New York, Asbestos-Cement Products Association.
** "Advanced Designing with Asbestos Siding," New York Asbestos-Cement Products Assoc.
The colors are permanently embedded throughout the
sheet. They will not powder or peel off. Different methods to improve the weather resistance of siding have been
They are used in the dry process. Sodium silicates
are one of the materials used for this purpose. Originally,
they were not successful since they were only insoluble after
baking at temperatures higher than 900Â°F.
tempera-ture condition is detrimental to the cement base. A
combina-tion of sodium silicate and sodium fluoborate becomes stable
when heated at 500Â°F for 1/9 hr. After the reaction has
occurred, an insoluble semi-gloss finish is produced. To
pro-duce approximately one ton of material, 48 lb of sodium
silicate and 6 lb of sodium fluoborate can be used with 16
lb of water and 18 lb of iron oxide pigment.
Silicone resins have been developed for use with
asbestos-cement shingles to provide for a water repellent structure.
One example involves coating a silicone composition on
shingles to make them water repellent and bloom resistant.
Asbestos Cement Siding: some building siding materials contain asbestos: Cement-asbestos siding shingles (photo at left) (non-asbestos-containing replacement products now available) and cement asbestos board siding as well as undersheeting.
This is a cementious material and is unlikely to release significant levels of airborne asbestos fibers unless during severe demolition activities or someone using a power saw or sander on the material.
See ASBESTOS CEMENT SIDING for more details about cement asbestos building siding, its repair, removal, demolition, or cover-over.
Manufacture of Asbestos Cement Roofing Shingles
Asbestos-cement roofing shingles
provide for permanent and decorative structures.
resistant and fire resistant characteristics of shingles make
them desirable for both industrial and home applications.
They provide for one of the light, weight-high strength
They are available in colors which range from
light pastels to deep tones and include both white and black.
Some shingles are designed in solid colors, while others
pro-vide a blended color effect..
Painting is not needed to
pre-serve shingles but if a change in color is desired, they can
(FIBER CEMENT SIDING PAINTS)
Asbestos-cement flat sheets were at one time
manufactured only in the typical gray color of cement and
usually only accepted for industrial purposes. However, they
are now available in such a variety of colors and surface
finishes that their usefulness has been greatly expanded.
Chrysotile asbestos is thge principal source for these products.
* Philadelphia Quartz Co.. 32, No. 6, P and Q, Philadelphia, Penna.
** Union Carbide Corp., American Patent 2, 833. 673 (May 6. 1958).
Sheets are available with smooth surfaces; they are waxed
or lacquered with a variety of colors for use as office
parti-tion walls, kitchen walls, table tops, acoustical panels,
elec-trical sheets, building corridors; they are used generally
where ease of cleaning is important.
Flat sheets are used both internally and externally.
Ex-terior sheets are made so that they resist outdoor weather.
They are impervious to water; they prevent the
entrap-ment of moisture within the building walls, a situation
which would normally cause the decay of wood. Decorative
sheets can be used for table tops to provide chemical
Complete asbestos-cement boards or flat sheets are used;
however, combinations incorporate asbestos-cement in
sand-wich structures. "Transitop" * is a typical composition
board consisting of an integrally impregnated insulating
board core, faced on both sides with asbestos-cement board.
Waterproof adhesive is used to laminate the insulating core
as well as to bond the noncombustible asbestos-cement faces
to the core.
This combination of materials provides for
structural strength, high insulation values and
maintenance-free interior and exterior finish in a single fire-resistant
panel. See Table 3.2. It is suitable for indoor or outdoor use.
The wood fiber insulating core is integrally impregnated to
provide maximum strength and a highly resistant barrier
to moisture without appreciably affecting the insulating
The conductivity of the core complies with
Federal Specification LL.L-F-321h-Class A. The sheet products
are also used where electrical requirements exist. Examples
of electrical applications are provided by Canadian
Specifications; Spec. 34-GP-8 pertains to asbestos-cement
Asbestos Cement board used as a "fire proofing" over and near boilers and wood stoves - also called "cement wallboard" and "asbestos millboard".
Asbestos millboard (photo at above left) used for stoves and heaters, in garages, as fireproof wallboard, as gaskets, as washers in electrical applications, stove mats,
safes, motion picture booths, automobile hoods. Asbestos millboard is a cementious product that was produced in sheets and used for fire barriers and in other applications.
The material is quite similar to cement asbestos roof shingles and siding, and was produced in sheets of varying thickness (typically 1/8"- 1/4") and dimension depending on its intended use.
Asbestos millboard was used as a fire barrier behind and over and around wood stoves, coal stoves, & heating appliances in buildings up to 1978. It was also used in some locations where a moisture-resistant building material was desire.
Rosato detailed the production of asbestos millboard. He described asbestos millboard as a "heat insulation" product, an apellation with which we disagree. Because of its dense and cementious nature asbestos millboard, while fireproof, can conduct heat towards combustible materials that it might cover, such as wood framing. Without an adequate air space or other insulation, heat conducted through non-combustible materials can still result in a fire. (Rosato 1959, 100-102)
Perforated cement-asbestos sheets are manufactured with
sound absorbing elements. These particular sheets are used
in broadcasting studios, music rooms, and auditoriums where
specific resistance to fire and moisture exists. Federal Spec-
ifications SS-A-118b, Type 2a and Class A are applicable.
TABLE 3.2 PHYSICAL PROPERTIES OF ASBESTOS TRANSITOP *
(Units expressed in Btu/sq ft/ Â° F/hr)
1 1/8 in.
1 9/16 in.
1 5/16 in.
1 3/4 in.
Approximate wt, uncrated, lb/sq.ft.
Conductance of iimpregnated insulating core
Transitop wall coefficients air to air ("U") value
Inside walls and partitions
Transitop surface to surface coefficients, conductance
* Johns-Manville corp.
Manufacture of Asbestos Cement Corrugated Sheets.
Asbestos-cement corrugated sheets are
generally only produced in the color gray.
use has been for industrial walls and roofs where corrosion
resistance is important. In recent years, this type product
has been incorporated in farm buildings, commercial
in-teriors and home exteriors. Its principal use on the farm is
based on fire safety, strength and resistance to rats and
Our photo, left, shows typical corrugated asbestos cement roofing installed. The dark areas are probably algae and the light reddish-brown areas may be a form of lichens.
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 Asbestos, its Industrial Applications, D.V. Roasato, engineering consultant, Newton MA, Reinhold Publishing Co., NY, 1959, Library of Congress Catalog No. 59-12535. We are in process of re-publishing this interesting text. Excerpts & adaptations are found in InspectApedia.com articles on asbestos history, production & visual identification in and on buildings.
 "Asbestos in Plastic Compositions", A.B. Cummins, Modern Plastics [un-dated, pre 1952]
 "Asbestos in Your Home," Spokane County Air Pollution Control Authority, Spokane WA 509-477-4727 www.scapa.org provides a one-page image, a .pdf file drawing of a house warning of some possible sources of asbestos in the home. The sources are not ranked according to actual risk of releasing hazardous levels of airborne asbestos fibers and the list is useful but incomplete.
 The US EPA provides a sample list of asbestos containing products epa.gov/earth1r6/6pd/asbestos/asbmatl.htm
 "Characterization of asbestos exposure among
automotive mechanics servicing and handling
asbestos-containing materials", Gary Scott Dotson, University of South Florida, 1 June 2006, web search 3/9/2012 original source: scholarcommons.usf.edu/cgi/viewcontent.cgi?article=3505&context=etd [copy on file as /hazmat/Automotive_Asbestos_Exposuret.pdf ].
 Thanks to Susan Kimball, Argus Pacific Corp., Puget Sound, WA, for pointing out that some products are permitted to contain more than 1% asbestos fibers by current standards provided that the fibers are encapsulated in an appropriate binder. Argus Pacific, in Seattle, WA 98119, 206.285.3373, is an industrial hygiene firm who also provide OSHA and DOSH regulated training in Washington State, providing classes in asbestos, lead, mold, hazardous waste, emergency response, and other occupational health, safety, and professional development topics. -- September 2008.
Work Practice for Window Removal and Window Putty Patching
With Less Than Or Equal To 1% Asbestos Window Putty and Caulking" University of Washington, 2002 http://www.washington.edu/admin/asbestos/1putty.html
 How do I Manage Asbestos in our House or Apartment Building?, Illinois Department of Environmental Conservation, provides this article at http://www.epa.state.il.us/small-business/asbestos-in-home/
 "Asbestos Awareness Training Outline", Michigan Department of Licensing and Regulatory Affairs, Michigan Occupational Safety & Health Administration, Construction Safety & Health Administration - asbestos program, Michigan Department of Licensing and Regulatory Affairs
Michigan Occupational Safety & Health Administration
Construction Safety and Health Division
7150 Harris Drive, P.O. Box 30671
Lansing, Michigan 48909-8171
Phone: 517.322.1320, Fax: 517.322.1713
E-mail: firstname.lastname@example.org, web search 3/9/12, original source www.michigan.gov/ [copy on file as /hazmat/Asbestos_awareness_training.pdf ]
 Damian Murphy, Marin OHS&E Consulting,Mairin OHS&E Consulting Pty Ltd
18-20 Kirk Street
Moe Vic 3825
P: 03 5127 2311
F: 03 5127 2399
E: email@example.com, personal correspondence to Daniel Friedman. 3/12/2013 Website: www.mairin.net.au
 Asbestos in buildings - employee notice, University of Washington dept. of Environmental Safety, http://www.ehs.washington.edu/ohsasbestos/index.shtm
 Window putty to be exempted from asbestos removal by State of Maine - http://list.uvm.edu/cgi-bin/wa?A2=SAFETY;wYpdKg;20010307113643-0500A
 EPA Region 6 identifies window putty as asbestos containing - http://www.epa.gov/earth1r6/6pd/asbestos/asbmatl.htm
June 1997 - Window Putty - OSHA case cites contractor for asbestos exposure during removal of window putty http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=NEWS_RELEASES&p_id=1091
 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
 EM>Asbestos in Your 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
"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 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, text and images available at InspectAPedia.com).
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
Or choose the The Home Reference eBook for PCs, Macs, Kindle, iPad, iPhone, or Android Smart Phones. Special Offer: For a 5% discount on any number of copies of the Home Reference eBook purchased as a single order. Enter INSPECTAEHRB in the order payment page "Promo/Redemption" space.