TERNE METAL ROOFING, or Terne II coated metal roofing are used where copper roof runoff or corrosion are special concerns.
Terne coated stainless steel roof panels (Terne coating is a a zinc-tin alloy metal coating process that gives extra corrosion resistance. Terne metals produced acccording to US ASTM A308 are expected to contain alloys copper, nickel, chromium, molybdenum, vanadium, titanium, columbium, and boron, at alloy mixes depending on the specific product requirement.
Other terne coatings using lead or tin can present an environmental contamination worry from lead leachate found in roof runoff.) Some terne-coated metals described by the galvanized-zinc industry use a terne coating that is comprised of 95-97% lead and 3-15% tin alloyed together. - American Galvanizers Assoc. (ret. 2015).
In the UK "Ternplate" is defined as follows:
Terneplate, steel sheet with a coating of terne metal, an alloy of lead and tin applied by dipping the steel in molten metal. The alloy has a dull appearance resulting from the high lead content. The composition of terne metal ranges from 50–50 mixtures of lead and tin to as low as 12 percent tin and 88 percent lead. The tin serves to wet the steel, making possible the union of lead and iron, which would otherwise not alloy. Terneplate is made by a process similar to galvanizing or tinplating—i.e., by dipping the sheets into a series of heated baths, the first of a zinc chloride flux, followed by the molten terne metal, and finally one of palm oil. Terneplate has the strength and formability of steel and the noncorrosive surface and solderability of terne metal. While it is still used for roofing, gutters and downspouts, and casket linings and in the manufacture of gasoline tanks for automobiles, oil cans, and containers for paints, solvents, resins, and so on, it has largely been replaced by other, more durable steel products that are easier to manufacture. - Encyclopedia Britannica, - retrieved 20 April 2015, original source: http://www.britannica.com/EBchecked/topic/588065/terneplate
According to the US NPS, "Terneplate was first produced in United States in New York in 1825. Joseph Truman of Philadelphia patented the lead coating of tinplate in 1831. Later production combined the lead and tin into a single coating.
Called variously "leaded plate," "roofing tin", and "roofing plate," terne was cheaper than a pure tin coating, but its properties were very similar. Domestic production of terne was twice that of tin when it was chosen to roof the buildings of the 1893 World's Columbian Exposition. In the next few decades terne replaced tin completely in American production as steel replaced iron as the base metal.
Terne metals are produced by coating carbon steel, stainless and other select metals with a specially formulated alloy consisting of zinc, tin and trace amounts of other elements in order to dramatically increase a metal’s corrosion resistance as much as ten times.
When terne was first used, during the colonial era, it contained roughly 80 percent lead and 20 percent tin. However, in the latter half of the 20th century, as lead was found to have potentially detrimental health effects, the lead/tin alloy had to be replaced. Seven years of metallurgic research and development produced a new and superior zinc/tin alloy in the mid-1990s. This new alloy, proven through ASTM corrosion resistance testing, provides improved performance and aesthetics over the original, minus potential risk to health.
Besides stainless and carbon steel, the zinc/tin alloy may also be applied to other metals such as copper, bronze, tin and titanium.
Available in a variety of gauges and widths, today terne metals are used on industrial, commercial, institutional, and residential structures for roofing, gutters and downspouts, siding, soffits, fascias and numerous other architectural applications.
A terne roof using a carbon steel substrate can easily last more than 100 years with very little maintenance required.
According to Follansbee, a West Virginia roofing company
Terne II roofing (also coated with zinc and tin), offering enhanced corrosion resistance, can be used in flatlock, standing seam, and vertical metal wall covering designs in any application where original Terne was used.
The company adds that with Terne II roofing the material should be painted as soon as conditions permit.
Oxide formation is slower than with the original Terne and the wait for proper painting conditions provides substantially less risk.
Tin plated iron and Terne Roofs - according to the US NPS, on early U.S. buildings, "Rolled sheet zinc appeared in the United States in 1816, as roofing in New York and as downspouts and gutters in Baltimore. Though more than seventy houses in New York had zinc roofs by 1837, it was out of favor by 1840. The popularity of the material was cyclical in the next decades, never matching iron and steel with their various coatings."
Terne Metal Specifications & Standards
ASTM A308 / A308M - 10, "Standard Specification for Steel Sheet, Terne (Lead-Tin Alloy) Coated by the Hot-Dip Process", available from ASTM, website from which we quote excerpts from the Standard's abstract. See www.astm.org - retrieved 20 Apr 2015
This specification covers sheet steel in coils and cut lengths coated with lead-tin alloy by the hot-dip process. The material, also known as terne-coated sheet, is available in four designations as commercial steel, deep drawing steel, extra deep drawing steel, and structural steel. Amount of copper, nickel, chromium, molybdenum, vanadium, titanium, columbium, and boron shall conform to the chemical composition requirements of this specification. Yield strength, tensile strength, elongation, and bending shall conform to the mechanical property requirements.
This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.
1.1 This specification covers sheet steel in coils and cut lengths coated with lead-tin alloy (terne metal, see 3.2.3) by the hot-dip process. This material is commonly known as terne and is used where ease of solderability and a degree of corrosion resistance are desirable. It is especially suitable where resistance to gasoline is required. Terne-coated sheet is also used for stamping, where the coating acts as a lubricant in the die, lessening difficulties in drawing. The weight of coating, always expressed as total coating on both sides, shall be specified in accordance with Table 1.
1.2 Material furnished under this specification shall conform to the applicable requirements of the latest issue of Specification A924/A924M, unless otherwise provided herein.
1.3 Terne-coated steel is available in a number of designations, types, and grades.
1.4 This specification is applicable to orders in either inch-pound units (as A308) or SI units (as A308M). Values in inch-pound and SI units are not necessarily equivalent. Within the text, SI units are shown in brackets. Each system shall be used independently of the other.
1.5 Unless the order specifies the “M” designation (SI units), the product shall be furnished to inch-pound units.
Terne Metal Roofing Sources, Products, & Manufacturers
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American Galvanizers Association, "Zinc Coatings, A comparative analysis of process and performance characteristics",
American Galvanizers Association,
6881 S. Holly Circle, Suite 108
Centennial, CO 80112
720-554-0900 | 800-468-7732
"Choosing Roofing," Jefferson Kolle, January 1995, No. 92, Fine Homebuilding, Taunton Press, 63 S. Main St., PO Box 5506, Newton CT 06470 - 800-888-8286 - see http://www.taunton.com/FineHomebuilding/ for the magazine's website and for subscription information.
 Follansbee Roofing, Follansbee WV 26037, Tel: 800-624-6906, website: www.follansbeeroofing.com and http://www.follansbeeroofing.com/products/TerneII.aspx Quoting Follansbee on TerneII properties:
Follansbee Steel is the only manufacturer of a pre-painted or natural Terne roof and is a leading supplier of metal roofs for new and retrofit commercial, institutional, residential and historic preservation projects.
Terne II - Classic Terne-Coated Steel
... is a new and improved version of historic Terne metal, ... Terne II has improved capability for resisting corrosion in all environments ... also has excellent formability, solderability, and affinity for paint ... without compromising mechanical characteristics. It can be used in flatlock, standing seam, vertical wall designs and virtually any other application in which original Terne has been used. It is strong and ductile, having high yield and tensile strengths as well as workability. This new material can easily be formed with conventional roofing tools.
With Terne II roofing, it is advisable to paint the material as soon as conditions permit. Oxide formation is slower than with the original Terne and the wait for proper painting conditions provides substantially less risk. The new material is coated with Follansbee's new ZT® alloy, a combination of zinc and tin. This coating is designed not only as a barrier but also to be anodic to the steel substrate and reduce the potential for oxidation before painting.
The traditional oil-based paints long required on original Terne are not recommended for application on Terne II. Follansbee's Rapidri paint with its faster drying time and ease of application is much superior to the old painting system. The Rapidri acrylic paints are aesthetically pleasing while offering enhanced durability and color retention. ...
Metal Roofing Alliance, E. 4142 Hwy 302, Belfair, WA 98528, Telephone:(360) 275-6164, Customer Support 410-534-6900, Email: email@example.com,
Website: www.metalroofing.com. Quoting:
The Metal Roofing Alliance was formed in 1998 by a small group of forward-thinking metal roofing manufacturers with the main goal of educating consumers about the many benefits of metal roofing. Since our inception, we've shown millions of people just how beautiful, durable and money-saving metal roofing can be for them. Over the years, our membership has grown to include paint companies, material suppliers, industry publications and more. Be sure to take advantage of all of the great resources our members offer.
The Metal Initiative, 4700 W. Lake Ave., Glenview, IL 60025, P:847.375.4785 Website: www.themetalinitiative.com/, Email: Louise Ristau firstname.lastname@example.org Quoting:
The Metal Initiative is a coalition of manufacturers, individuals and associations that have come together to provide information on the features and benefits of metal in construction. Carrying its message of metal primarily to the professional building owner community, The Metal Initiative seeks to gather and disseminate useful information for decision-makers.
Problems in Roofing Design, B. Harrison McCampbell, Butterworth Heineman, 1991 ISBN 0-7506-9162-X (available used)
Grapevine Design Guidelines - Web Search 07/12/2010
"Copy on file as - /roof/Asbestos-to-Zinc_Metal_Roofing_NPS.pdf - From Asbestos to Zinc, Roofing for Historic buildings, Metals - ", Technical Preservation Services, National Park Service, U.S. Department of the Interior, web search 9./29.10, original source:
"Copy on file as - /roof/Asbestos-to-Zinc_Metal_Roofing_NPS_3.pdf - From Asbestos to Zinc, Roofing for Historic buildings, Metals-part II, Coated Ferrous Metals: Iron, Lead, Zinc, Tin, Terne, Galvanized, Enameled Roofs - ", Technical Preservation Services, National Park Service, U.S. Department of the Interior, web search 9./29.10, original source:
"On file as /roof/Asbestos-to-Zinc_Metal_Roofing_NPS_2.pdf - From Asbestos to Zinc, Roofing for Historic buildings, Metals- Roofing Today - ", Technical Preservation Services, National Park Service, U.S. Department of the Interior, web search 9./29.10, original source:
"Copy on file as - /roof/Roofing_Historic_NPS.pdf">Roofing for Historic buildings - ", Sarah M. Sweetser, Preservation Brief 4, Technical Preservation Services, National Park Service, U.S. Department of the Interior, web search 9./29.10, original source:
"Copy on file as - /exterior/NPS_Preserv_Brief_16_Subs_Mtls.pdf">The Use of Substitute Materials on Historic Building Exteriors - ",
Sharon C. Park, AIA, Preservation Brief 16, Technical Preservation Services, National Park Service, U.S. Department of the Interior, web search 9./29.10, original source:
ARMA - Asphalt Roofing Manufacturer's Association - http://www.asphaltroofing.org/
750 National Press Building, 529 14th Street, NW, Washington, DC 20045, Tel: 202 / 207-0917
"Metal Roofing: 'Fixing' for Thermal Movement [ copy on file as /roof/Metal_Roof_Movement_NRCA.pdf ] - ", Thomas L. Smith, AIA, CRC., Professional Roofing, [date pending] p. 72, NRCA
"Metal Roof Systems: Design Considerations for Snow and Ice [ copy on file as /roof/Metal_Roof_Snow_Ice_NRCA.pdf ] - ", Thomas L. Smith, AIA, CRC., Professional Roofing, [date pending] p. 74, NRCA
"Steel [Roof] Decks: Issues for the 1990's [ copy on file as /roof/ Steel_Roof_Deck_Corrosion1_NRCA.pdf ] - ", Thomas L. Smith, AIA, CRC., Professional Roofing, [date pending] p. 74, NRCA
"Steel [Roof] Deck Corrosion Bulletin, NRCA [ copy on file as /roof/Steel_Roof_Deck_Corrosion_NRCA.pdf ] - ", Thomas L. Smith, AIA, CRC., Professional Roofing, [date pending] p. 58, NRCA
"The Many Aspects of Metal [Roof] Shingles [copy on file as Metal_shingles_NRCA.pdf ] - ", Thomas L. Smith, AIA, CRC., Professional Roofing, [date pending] NRCA
Cedar Shake & Shingle Bureau, CSSB, U.S.: Sumas, WA 98295-1178, Tel: 604-820-7700, In Canada:
Cedar Shake and Shingle Bureau #2 - 7101 Horne Street, Mission, BC V2V 7A2 Tel: (604) 820-7700, E-mail: email@example.com , website: http://www.cedarbureau.org/
Forest Products Laboratory, US FPL, One Gifford Pinchot Drive, Madison, WI 53726, Tel: (608) 231-9200, Email: firstname.lastname@example.org, website: http://www.fpl.fs.fed.us/
NRCA - National Roofing Contractors Association - http://www.nrca.net/, 10255 W. Higgins Road, Suite 600,
Rosemont, IL 60018-5607, Tel: (847) 299-9070
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