Snow brakes, or snow guards are used on metal roofs covering buildings in snow-prone areas. Our photo (left) shows snow guards on a modern computing center building on the Bard College campus, Annandale, NY.
As a safety measure to avoid clobbering someone entering or exiting the building at a bad moment
To avoid knocking gutters off of the structure. Properly placing gutters so that the outermost gutter edge is at or below the extended roof slope plane can help prevent ice or snow from knocking gutters off, though in heavy snow areas we often see that homeowners have given up on the idea of keeping gutters on a metal-roofed home, using other means to direct roof runoff away from the building.
To avoid piles of snow on entrance steps and platforms
As we discuss at
SNOW GUARDS, Snow guards and a bit of their history are discussed in NPS "From Asbestos to Zinc" from which we quote:
Snow guards or snow brakes, as they are sometimes called, began appearing on slate and metal roofs of New England in the late 1800s. The tremendous quantities of snow and ice that accumulated on these roofs made the wood or metal diverter, typically attached above the front entry, an ineffective tool in preventing the snow from sliding down the roof.
With snow guards in place, the snow would eventually blow away or remain until it melted. Not only was the risk of damage to objects and persons below avoided, but the banking of snow and ice at the eaves was prevented, thus eliminating the chances of backwater and consequent leaks, as well as a straining of the gutter structure.
This photo of snow brakes on a standing seam metal roof demonstrates that snow guards or snow hooks were widely used on metal roofs for more than 100 years.
At
SNOW GUARDS we show more snow brakes and guards used on slate roofs.
Photographs of Slate Snow Guards & Snow Hooks
Snow guards and a bit of their history are discussed in NPS "From Asbestos to Zinc" from which we quote:
Snow guards or snow brakes, as they are sometimes called, began appearing on slate and metal roofs of New England in the late 1800s. The tremendous quantities of snow and ice that accumulated on these roofs made the wood or metal diverter, typically attached above the front entry, an ineffective tool in preventing the snow from sliding down the roof.
With snow guards in place, the snow would eventually blow away or remain until it melted. Not only was the risk of damage to objects and persons below avoided, but the banking of snow and ice at the eaves was prevented, thus eliminating the chances of backwater and consequent leaks, as well as a straining of the gutter structure.
Below we include our own photographs of snow brakes, snow guards, snow hooks, and other on-roof devices to control against snow damage and hazards, including snow guard examples and materials from the 1800's up to 2010.
Snow Guard Hooks, and heat tapes - suspect ice dam leaks or ice falling at building entry
Snow Hooks, generally good slates, note bleed out from a few slates with mineral inclusions
Here are new copper snow guards being installed on a slate roof that was also being replaced/repaired on the Wimpfheimer Nursery building on the Vassar College Campus, Poughkeepsie, NY - March 2010.
Classic Products
www.classicroof.com
Modular metal shingle panels and standing seam panels
Decra Roofing Systems
www.decra.com
Modular metal shingle, tile, and shake panels
Dura-Lok Roofing Systems
www.duraloc.com
Modular metal roofing shingles with granular coating
Fabral
www.fabral.com
Exposed fastener and concealed clip metal roofing
panels
Gerard Roofing Technologies
www.gerardusa.com
Modular metal shake and tile panels with granular
coating
Met-Tile
www.met-tile.com
Modular metal roof-tile panels
Atas International
www.atas.com
Modular metal shingle, tile, and standing-seam panels
Custom-Bilt Metals
www.custombiltmetals.com
Modular metal shakes and standing seam panels
Zappone Manufacturing, website www.zappone.com/
Zappone Manufacturing, 2928 North Pittsburg St. Spokane, WA 99207
1-800-285-2677, Washington State Copper Roofing Supplier of
Copper scallop shingles, copper shingles, copper bay windows, vertical walls, aluminum roof shingles
Venting Underlayments
Benjamin Obdyke
www.benjaminobdyke.com
Cedar Breather, a
3/8 -in.-thick matrix-type underlayment
designed to provide ventilation and drainage space under
wood roofing
More Information about Roofing Materials, Methods, Standards
Asphalt Roofing Manufacturers Association (ARMA)
www.asphaltroofing.org
Cedar Shake and Shingle Bureau
www.cedarbureau.org
Steven Bliss served as editorial director and co-publisher of The Journal of Light Construction for 16 years and previously as building technology editor for Progressive Builder and Solar Age magazines. He worked in the building trades as a carpenter and design/build contractor for more than ten years and holds a masters degree from the Harvard Graduate School of Education.
Excerpts from his recent book, Best Practices Guide to Residential Construction, Wiley (November 18, 2005) ISBN-10: 0471648361, ISBN-13: 978-0471648369, appear throughout this website, with permission and courtesy of Wiley & Sons. Best Practices Guide is available from the publisher, J. Wiley & Sons, and also at Amazon.com.
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Additional technical contributors & reference sources for this article are listed below.
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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
ASTM - ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA, 19428-2959 USA The ASTM standards listed below can be purchased in fulltext directly from http://www.astm.org/
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
UL - Underwriters Laboratories - http://www.ul.com/
2600 N.W. Lake Rd.
Camas, WA 98607-8542
Tel: 1.877.854.3577 / Fax: 1.360.817.6278
E-mail: cec.us@us.ul.com
"From Asbestos to Zinc, Gutters", 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/gutters.htm
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, and from the InspectAPedia bookstore. The 2010 edition of 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.
Architectural elements: the technological revolution: Galvanized iron roof plates and corrugated sheets; cast iron facades, columns, door and window caps, ... (American historical catalog collection), Diana S Waite, available used out of Amazon.
Green Roof Plants: A Resource and Planting Guide, Edmund C. Snodgrass, Lucie L. Snodgrass, Timber Press, Incorporated, 2006, ISBN-10: 0881927872, ISBN-13: 978-0881927870. The text covers moisture needs, heat tolerance, hardiness, bloom color, foliage characteristics, and height of 350 species and cultivars.
Green Roof Construction and Maintenance, Kelley Luckett, McGraw-Hill Professional, 2009, ISBN-10: 007160880X, ISBN-13: 978-0071608800, quoting: Key questions to ask at each stage of the green building process Tested tips and techniques for successful structural design
Construction methods for new and existing buildings
Information on insulation, drainage, detailing, irrigation, and plant selection
Details on optimal soil formulation
Illustrations featuring various stages of construction
Best practices for green roof maintenance
A survey of environmental benefits, including evapo-transpiration, storm-water management, habitat restoration, and improvement of air quality
Tips on the LEED design and certification process
Considerations for assessing return on investment
Color photographs of successfully installed green roofs
Useful checklists, tables, and charts
Problems in Roofing Design, B. Harrison McCampbell, Butterworth Heineman, 1991 ISBN 0-7506-9162-X (available used)
Roofing The Right Way, Steven Bolt, McGraw-Hill Professional; 3rd Ed (1996), ISBN-10: 0070066507, ISBN-13: 978-0070066502
Slate Roofs, National Slate Association, 1926, reprinted 1977
by Vermont Structural Slate Co., Inc., Fair Haven, VT 05743, 802-265-4933/34. (We recommend this book if you can find it. It
has gone in and out of print on occasion.)
Roof Tiling & Slating, a Practical Guide, Kevin Taylor, Crowood Press (2008), ISBN 978-1847970237, If you have never fixed a roof tile or slate before but have wondered how to go about repairing or replacing them, then this is the book for you. Many of the technical books about roof tiling and slating are rather vague and conveniently ignore some of the trickier problems and how they can be resolved. In Roof Tiling and Slating, the author rejects this cautious approach. Kevin Taylor uses both his extensive knowledge of the trade and his ability to explain the subject in easily understandable terms, to demonstrate how to carry out the work safely to a high standard, using tried and tested methods.
This clay roof tile guide considers the various types of tiles, slates, and roofing materials on the market as well as their uses, how to estimate the required quantities, and where to buy them. It also discusses how to check and assess a roof and how to identify and rectify problems; describes how to efficiently "set out" roofs from small, simple jobs to larger and more complicated projects, thus making the work quicker, simpler, and neater; examines the correct and the incorrect ways of installing background materials such as underlay, battens, and valley liners; explains how to install interlocking tiles, plain tiles, and artificial and natural slates; covers both modern and traditional methods and skills, including cutting materials by hand without the assistance of power tools; and provides invaluable guidance on repairs and maintenance issues, and highlights common mistakes and how they can be avoided.
The author, Kevin Taylor, works for the National Federation of Roofing Contractors as a technical manager presenting technical advice and providing education and training for young roofers.
The Slate Roof Bible, Joseph Jenkins, www.jenkinsslate.com,
143 Forest Lane, PO Box 607, Grove City, PA 16127 - 866-641-7141 (We recommend this book).
Solar heating, radiative cooling and thermal movement: Their effects on built-up roofing (United States. National Bureau of Standards. Technical note), William C Cullen, Superintendent of Documents, U.S. Govt. Print. Off (1963), ASIN: B0007FTV2Q
"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