Snow curls off of  New York roof that has no snow retention system installed (C) 2013 D Friedman Roof Install, Inspect & Repair

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Building roofs:

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.

Roofing Installation, Inspection, Diagnosis & Repairs

Photograph of  really worn out asphalt roof shinglesExample 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.

  1. 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.
  2. 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.
  3. 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.
  4. 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

Roof slope definitions and illustrations (C) Carson Dunlop Associates

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


Roof Covering Fire Resistance or "Fire Ratings"

Thermal splitting of fiberglass-based asphalt roof shingles was particularly common for product manufactured in the early 1990's.

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



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Publisher - Daniel Friedman