Aluminum metal roofing, first used in the U.S. in 1890 on Philadelphia's City Hall, difficult to solder, relied on mechanical joints and slope to shed water. Details about aluminum roofing are at ALUMINUM ROOFING.
Aluminum Metal Roofing System Properties
Aluminum that is anodized or painted is
highly resistant to corrosion, making it well-suited to
coastal environments provided it is factory-coated with a suitable finish. (although lightweight aluminum
flashings tend to pit and oxidize in salty air).
Aluminum roofing's light
weight is an advantage in reroofing. Aluminum roofing also reflects heat and may thus reduce building cooling costs in hot sunny climates.
Because of its high
coefficient of expansion, however, attachment systems
must be designed to accommodate the movement of long
aluminum roof panels.
And since it has a lower tensile strength than steel,
more fasteners may be required to achieve wind ratings
comparable to a steel roof.
Aluminum roofing, softer than steel or copper, dents easily and so may suffer cosmetic damage from hail. Hail damage is reduced if the aluminum panels are well secured to solid roof decking.
Also, aluminum has a low melting
point so it relies on two layers of fire-resistant underlayment,
such as VersaShield, to get a Class A fire rating.
Most aluminum used in roofing has a baked-on paint
finish rather than an anodized finish. Although anodized
aluminum is less costly, new paint technologies such as
Kynar® and Hylar® carry better warranties and are available
with a low-gloss finish generally favored on roofs.
Some coated aluminum products come with transferable
lifetime warranties.
Aluminum roof noise
Depending on how the roof is installed, secured, and insulated, an aluminum metal roof may be noisy. See ROOF NOISE TRANSMISSION where we describe the noise transmission properties of metal roofing.
Metal roofs have a long history of use, although improvements have occurred in shop fabrication methods and new sealant materials. Metal roofs are available in a wide variety of rib configurations, colors, and slope configurations. Architectural systems use an underlying deck to provide structural support, while structural standing seam metal roofs provides an integral supporting frame. Structural systems can be used to retrofit an existing flat roof deck to provide improved drainage. Sealant is required at valleys, gutters, and drains, to ensure water tightness.
Workmanship of the metal roof installation, including consideration for thermal and building-related movement in the roof system
Metal roof fasteners and connectors: proper selection and installation
Metal roof joints, proper design and installation to accommodate movement and thermal changes
Choice of metal, and exposure to particular environments: salt spray, chemicals from nearby factories, high winds, other weather conditions
The patched corrugated metal roofing shown below (left) covers a pre-1900 home currently used as a parsonage in Dover Plains, NY. This roof was a mix of corrugated galvanized steel and corrugated aluminum roofing.
At CORRUGATED ROOFING we discuss all types of corrugated roofing products: metal and others.
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"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.
[1] 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: support@metalroofing.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 lristau@connect2amc.com 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:
http://www.nps.gov/history/hps/tps/roofingexhibit/metals2.htm
"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:
http://www.nps.gov/history/hps/tps/roofingexhibit/metals.htm
"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:
http://www.nps.gov/history/hps/tps/roofingexhibit/roofingtoday.htm
"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:
http://www.nps.gov/history/hps/tps/briefs/brief04.htm
"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:
http://www.nps.gov/history/hps/tps/briefs/brief16.htm
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: info@cedarbureau.com , website: http://www.cedarbureau.org/
Forest Products Laboratory, US FPL, One Gifford Pinchot Drive, Madison, WI 53726, Tel: (608) 231-9200, Email: mailroom_forest_products_laboratory@fs.fed.us608-231-9200, 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
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 2010, $69.00 U.S., is available from Carson Dunlop. The Home Reference Book 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. InspectAPedia.com ® author/editor Daniel Friedman is a contributing author. Field inspection worksheets are included at the back of the volume.
"Weather-Resistive Barriers [copy on file as /interiors/Weather_Resistant_Barriers_DOE.pdf ] - ", how to select and install housewrap and other types of weather resistive barriers, U.S. DOE
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