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How to Install, Inspect, Diagnose, Repair Roofs; Roofing Defects, Product Sources, Installation Advice.
Roof inspection, installation, diagnosis, repair & replacement guide: these articles provide in-depth un-biased articles about building roofing materials, installations, inspection, roof problem or roof leak diagnosis and repair, roof covering or shingle product failures, roof warranties, roofing and roof structure defects, roofing repairs, and all types of roof covering products.
Page top Photo: collapsed barn, Cooperstown, NY leaves only its roof in view - Daniel Friedman
We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.
Example topics discussed in our building roofing articles include asphalt roof failures including thermal splitting and other defects,
causes and types of asphalt shingle roof leaks, shingle blow-offs and wind damage, shingle cracks, blisters, stains, thermal splitting, and other damage,
Fire retardant plywood roof sheathing defects.
How to find and choose a roofing contractor, How to inspect roofs, Roofing product failures, class actions, warranty claims, Roofing repair methods, Roofing product sources for Residential and light commercial roofs, Slate roof inspection and repair methods.
Our page top photo shows a current roof situation that deserves some thought. At left is a beautiful if complex roof over a Russian Orthodox temple in Buenos Aires. [Click to enlarge any image]
Our roofing inspection, diagnosis, repair and installation articles listed below provide roof inspection, roof leak or problem diagnosis, roof installation, and roof repair information as well as details about the factors that affect the life of any roof.
This website also includes detailed information about roofing age, life, inspection, troubleshooting, and repair.
Particular sources of roof damage such as hail damage, ice dam damage, and wind damage as well as insurance inspections and claims are explained here.
We discuss often-argued-about proper roof flashing, roof slope, roof job estimating, roofing felt or underlayment, roof ventilation, and we include roof warranty and claim information and links to roofing product sources. We also discuss roof safety hazards and safety procedures & standards for roofers.
To find what you need quickly, if you don't want to scroll through this index you are welcome to use the page top or bottom SEARCH BOX to search InspectApedia for specific articles and information.
Clay tile roofing material and installation labor are more expensive than alternate materials, but the material has a life expectancy of up to 350 years where high quality vitreous tiles are used. Clay tiles are heavy, weighing between 850 and 1,700 pounds per square.
See LEAKY ROOF DIAGNOSIS & REPAIR - This article describes procedures for finding and fixing all types of leaks in roofs, figuring out the actual spot where a roof leak is occurring, and methods for tracking down the source of water or wet spots on ceilings or in attics.
The first part of this article describes different types and causes of roof leaks - clues about how and where to look for the causes of a roof leak.
The second part of this article discusses how we track an actual roof leak backwards to its probable source or entry point on the roof. This article series helps with diagnosis and repair of roof leaks found in different types of roof coverings and different types of roof designs.
We distinguish among actual roof leaks during rainfall, unusual leaks during hurricanes and high winds, wind-blown rain leaks, ice dam leaks in northern climates, and attic condensation or HVAC ductwork condensation and icing that may be mistaken for a roof leak in any climate.
Low slope roofing refers to roofing systems for pitches below 4" in 12" of slope.
PLASTIC ROOFING TYPES - plastic roof shingles, some sold with a 50-year or lifetime warranty, produced by a variety of manufacturers. Unfortunately some models failed early.
Metal roofing material costs $35 - 250 per square (wide range because of wide range of types of metal roofing), with an installed cost of $35 - $400 / square, a life of 15-40 years or more (a roof kept properly coated can last longer), and weigh 50 - 270 pounds / square. A high end aluminum metal roof may cost $800 - $1000 / square.
METAL ROOFING where we provide articles on every type of metal roofing system and metal including for example:
Membrane roofing such as modified bitumen, rubber, or built up roofing using tar and gravel have a life expectancy of 20 - 40 years, varying significantly depending on materials and workmanship, and may cost $750 to $1000 per square.
SOD ROOFING - traditional in rural areas of North America and for hundreds of years in Europe. Photo guide to construction techniques.
Sprayed Polyurethane Foam - discussed in NPS article "Roofing Today" use of modern roof materials on historic buildings:
Sprayed polyurethane foam is a contemporary system that is sometimes appropriate for use on historic structures. Sprayed polyurethane foam (SPF) accepts a variety of substrates and is readily adapted to recovering existing flat or low sloped roofs.
This roofing can be designed to incorporate increased slope for better drainage. The foam also serves as insulation. A smooth or granular coating is usually applied to provide protection from sunlight.
Thatch Roofing - THATCH ROOFING addresses natural fiber roofs using brush, grass, similar materials.
Tile roofing is discussed in detail beginning
at TILE ROOFING - home, including ceramic tile, glazed tile and clay tile roof systems.
Wood roofing shingles and shakes material cost $150-200 per square, with an installed cost of $130 - $160 / square. Wood shingle roofs have a typical life expectancy of 10-40 years, and weigh 300-400 pounds per square.
The life of a wood shingle roof can vary widely depending on the wood species of shingles used and the treatment of wood roof shingles with preservative.
The cost of roofing installations varies considerably by geographic area as well as material selected, pitch and height of roof, and roof shape or design complexity.
Roofing cost estimates do not necessarily include the cost of any necessary structural or roof decking repairs that may be needed when re-roofing, nor do they include the cost of removing and disposing of old roofing materials.
All of these roofing materials have a fire rating of A except wood shingles which, if treated with a fire retardant, are fire rated B. Un-treated wood roof shingles have no fire rating and are not permitted by code in some areas.
A class A fire rated wood shingle roof can be installed using special procedures and materials that include plywood and gypsum board.
The life expectancy of any roof depends significantly on other factors besides its composition, including the installation workmanship, the condition of the roof decking, and proper roof ventilation. For best life expectancy, fiberglass based asphalt shingles should meet standard ASTM D-3462 and organic mat based asphalt roof shingles should meet standard ASTM D-225.
Architectural asphalt roof shingles can be expected to last longer than less-costly three-tab asphalt roof shingles.
See "Choosing Roofing" in Fine Homebuilding Magazine (1995 data shows relative costs; absolute prices will have changed).
Roof Slope or Roof Pitch Definitions
Summary of Definitions of Roof Slope Types: Flat, Low Slope, Steep Slope Roofs
The illustration just above, courtesy of Carson Dunlop & Associates, summarizes the ranges of roof pitch or slope for flat, low-slope or conventional or "steep slope" roofing.
Flat roof: 0-2" rise per foot of run
Low-Slope Roof: less than or equal to 3" rise per foot of run
Steep slope roof: 4" rise in 12 or more.
[Click to enlarge any image]
Details about how roof slope is measured or calculated along with examples of converting between angle, slope and grade are
In the U.S. and most other countries roof coverings are rated for their ability to resist fire and to avoid spreading fire if the building burns. Both UL 790 and ASTM E 108 fire classification tests use the same test methods.
Class "A" roof fire ratings mean that under the specifics of the UL (or ASTM) fire rating test definition, the roof is effective against severe fire exposure.
Class "B" roof fire ratings mean that the roof is effective against moderate fire exposure.
Class "C" roof fire ratings mean that the roof is effective against slight fire exposure only.
Details about roof fire resistance effectiveness and roof fire ratings are
ROOF ASSEMBLIES & ROOFTOP STRUCTURES [PDF], Chapter 8 of the 2013 California Building Code, California Office of State Fire Marshal, retrieved 2017/10/28, original source http://osfm.fire.ca.gov/codedevelopment/pdf/wildfire protection building construction/2013-Part-2-CBC-Sec1505.pdf
ROOF COVERINGS & BEST PRACTICES [PDF] FEMA, retrieved 2017/10/28, original source https://www.fema.gov/media-library-data/ 20130726-1706-25045-9347/chapter8.pdf
"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.
Owens Corning Corporation, One Owens Corning Parkway
Toledo, Ohio 43659
Telephone: (419) 248-8000
Fax: (419) 248-5337
http://www.owenscorning.com Owens Corning is credited as the inventor of fiberglass when Owens Illinois [O-I] researcher Dale Kleist and his colleague John Thomas stumbled onto and then realized the significance of producing glass fibers in 1932. O-I formed a joint venture with the Corning Glass Works in 1935, leading to the formation of Owens Corning Corporation in 1938. More on Owens Corning's history is at
Focus, Toledo, Ohio, Owens-Corning Fiberglas Corporation, October 1988.
"A History of Innovation," http://www.owenscorning.com, 1997.
Stewart, Thomas A., "Owens-Corning: Back from the Dead," Fortune, May 26, 1997.
International Directory of Company Histories, Vol. 20. St. James Press, 1998.
"Two-Year Wisconsin Thermal Loads for Roof Assemblies and Wood, Wood–Plastic Composite, and Fiberglass Shingles [on file as Roof_Thermal_Loads.pdf] - ",
Jerrold E. Winandy
Cherilyn A. Hatfield, US Department of Agriculture, US Forest Products Laboratory, Research Note FPL-RN-0301
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/
NRCA - National Roofing Contractors Association - http://www.nrca.net/, 10255 W. Higgins Road, Suite 600,
Rosemont, IL 60018-5607, Tel: (847) 299-9070 Fax: (847) 299-1183
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
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 /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:
copy on file as /roof/Asbestos-to-Zinc_Metal_Roofing_NPS_4 .pdf From Asbestos to Zinc, Roofing for Historic buildings, Metals-part III, Slate", 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_5 .pdf From Asbestos to Zinc, Roofing for Historic buildings, Metals-part IV, Wood", 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_5 .pdf From Asbestos to Zinc, Gutters", 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_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 /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
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
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
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).
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: email@example.com. The firm provides professional home inspection services & home inspection education & publications. Alan Carson is a past president of ASHI, the American Society of Home Inspectors. Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home. Carson Dunlop Associates' provides extensive home inspection education and report writing material.
The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors. Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page "Promo/Redemption" space.
TECHNICAL REFERENCE GUIDE to manufacturer's model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop, Associates, Toronto - Carson Dunlop Weldon & Associates Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.
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.
Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
The Horizon Software System manages business operations,scheduling, & inspection report writing using Carson Dunlop's knowledge base & color images. The Horizon system runs on always-available cloud-based software for office computers, laptops, tablets, iPad, Android, & other smartphones