Question? Just ask us!
Free Encyclopedia of Building & Environmental Inspection, Testing, Diagnosis, Repair
InspectAPedia ® Home
ROOFING INSPECTION & REPAIR
AGE OF ROOFING
AMERICAN CEMWOOD ROOFING
ARCHITECTURE & BUILDING COMPONENT ID
ASBESTOS IDENTIFICATION IN buildings
ASBESTOS CEMENT ROOFING
ASBESTOS MATERIAL REGULATIONS
ASBESTOS REGULATION Update
ASPHALT ROOF SHINGLES
ROOF ICE DAM LEAKS
BEST CONSTRUCTION PRACTICES GUIDE
BEST ROOFING PRACTICES
BUILDING SAFETY HAZARDS GUIDE
BUILT UP ROOFS
CERTIFICATIONS for ROOFING CONTRACTORS
CHIMNEY INSPECTION & REPAIRS
CHOOSING A ROOFING CONTRACTOR
CLAY TILE ROOFING
COLD WEATHER ROOF TROUBLE
DEBRIS STAINING on ROOFS
DECKS, ROOFTOP CONSTRUCTION
DEFINITIONS of ENGINEERED WOOD OSB LVL etc
DISASTERS: BUILDING INSPECTION & REPAIR
EARLY ROOF FAILURE DIAGNOSTIC QUESTIONS
EXTERIOR WALL SIDING TRIM & FINISHES
FELT UNDERLAYMENT REQUIREMENTS
FIBER CEMENT & FIBERBOARD ROOFING
FIRE RATINGS for ROOF SURFACES
FIRE RETARDANT PLYWOOD
FLASHING on BUILDINGS
FLASHING, ASPHALT SHINGLE VALLEYS
FLASHING, CHIMNEY Mistakes & Leaks
FLASHING, CLAY TILE ROOFS
FLASHING MEMBRANES PEEL & STICK
FLASHING for METAL ROOFS
FLASHING ROOF WALL DETAILS
FLASHING ROOF-WALL SNAFU
FLASHING SIDING DETAILS
FLASHING WALL DETAILS
FLASHING WINDOW DETAILS
FLASHING WOOD ROOF DETAILS
FLAT ROOF MOISTURE & CONDENSATION
GALVANIC SCALE & METAL CORROSION
Green House or Solarium Roof Leaks
GUTTERS & DOWNSPOUTS
HAIL DAMAGED SHINGLES
HEAT TAPES & CABLES on Roofs for Ice Dams
HOT ROOF DESIGNS: Un-Vented Roof Solutions
HOUSEWRAP INSTALLATION DETAILS
HUMIDITY LEVEL TARGET
ROOF ICE DAM LEAKS
INSECT INFESTATION / DAMAGE
INSULATION IDENTIFICATION GUIDE
INSULATION INSPECTION & IMPROVEMENT
LEAD POISONING HAZARDS GUIDE
LEAKY ROOF DIAGNOSIS & REPAIR
LEED GREEN BUILDING CERTIFICATION
LOW SLOPE ROOFING
MASONITE WOODRUF FIBERBOARD ROOFING
MEMBRANE & SINGLE PLY ROOFS
MODIFIED BITUMEN ROOFING
NOISE / SOUND DIAGNOSIS & CURE
NOISE CONTROL for ROOFS
PLASTIC ROOFING TYPES
ROLL ROOFING, ASPHALT
ROOF ARCHITECTURAL STYLES - PHOTO GUIDE
ROOF CLEANING RECOMMENDATIONS
ROOF COLOR RECOMMENDATIONS
ROOF DORMER TYPES - PHOTO GUIDE
ROOF INSPECTION SAFETY & LIMITS
ROOF JOB PROBLEMS, RESOLVING
ROOF LEAK DIAGNOSIS & REPAIR
ROOF NOISE TRANSMISSION
ROOF REPLACEMENT SNAFUs
ROOF SLOPE DEFINITIONS
ROOF VENTILATION SPECIFICATIONS
ROOFING FELT UNDERLAYMENT REQUIREMENTS
ROOFING MATERIALS, Age, Types
ROOFING TILE SHAPES & PROFILES
ROOFING UNDERLAYMENT BEST PRACTICES
SADDLE CONSTRUCTION at CHIMNEYS
SLATE ROOF INSPECTION & REPAIR
SNOW GUARDS & SNOW BRAKES
SOUND CONTROL in buildings
STAINS on & in BUILDINGS, CAUSES & CURES
STAIN DIAGNOSIS on BUILDING EXTERIORS
STAIN DIAGNOSIS on ROOFS
STAIN DIAGNOSIS on STONE
STANDARDS for ROOFING
STONE CLEANING METHODS
STRESS SKIN INSULATED PANELS
TEST LABS - ROOF SHINGLE
THERMAL EXPANSION of MATERIALS
THERMAL MASS in BUILDINGS
TREES & SHRUBS, TRIM OFF BUILDING
TRUSS UPLIFT, ROOF
TRUSSES, Floor & Roof
UNDERLAYMENT REQUIREMENTS on ROOFS
WALK-ON ROOF SURFACES
WARRANTIES for ROOF SHINGLES
WALL CONSTRUCTION BARRIER vs CAVITY
WATER ENTRY in buildings
WIND DAMAGE to ROOFS
WINDOWS & DOORS
WINTERIZE A BUILDING
WOOD SHAKE & SHINGLE ROOFING
WOOD ROOF COATINGS & FIRE RATINGS
WOOD ROOF INSPECTION GUIDE
Wood Roof Wear or Installation Problems
Wood Roof Moss & Lichens
WOOD ROOF INSTALLATION SPECS
Wood Roof Flashing Details
Wood Roof Hip & Ridge Details
WOOD ROOF LIFE EXPECTANCY
WOOD ROOF MAINTENANCE
WOOD ROOF SHAKES INSTALLATION
WOOD ROOF SHEATHING, UNDERLAYMENT
WOOD ROOF SHINGLE PROPERTIES
WOOD SHINGLES, RE-ROOFING WITH
WORKMANSHIP & ROOF DAMAGE
ZINC METAL ROOFING
This article discusses the properties of wood roof shingles and shakes, including shingle grades, wood species used in roofing, and wood roof shingle or shake warranties. This article series discusses best practices in the selection and installation of residential roofing. This article includes excerpts or adaptations from Best Practices Guide to Residential Construction, by Steven Bliss, courtesy of Wiley & Sons. Our page top photo shows a wood shingle roof on the historic Mesier Homestead in Wappingers Falls, NY.
Green links show where you are. © Copyright 2014 InspectApedia.com, All Rights Reserved.
A number of factors affect the longevity of a wood roof. Key factors include the durability of the wood, local humidity and precipitation levels, and whether the roofing was installed with adequate ventilation.
Other factors include the slope of the roof (steeper slopes shed water faster) and the presence of overhanging trees that shade the roof and drop organic debris onto the roof, trapping moisture on the surface. Some of these factors can be controlled by the contractor; some managed by the homeowner. Others, like the weather or the reduced durability of second-growth cedar, are beyond our control.
Some simple steps that a homeowner can take to prolong the life of a wood roof include:
Over time, the natural extractives in cedar and other decay-resistant species will leach out, making the wood vulnerable to decay. Also, as the shingles dry out, they are prone to cupping, checking, and splitting. At some point, it may make sense to wash and treat the entire roof.
Washing or Cleaning Advice for Wood Roofs
Cleaning wood roofs with high-pressure equipment is controversial and, in untrained hands, can cause significant damage. It is best to use normal garden hose pressure along with a brush or pump sprayer. To remove dirt, mildew, and weathered gray residue, a consortium of wood technology and coatings experts, including the U.S. Forest Products Laboratory (FPL), recommend a solution of sodium percarbonate (disodium peroxydicabonate) and water.
With redwood and cedar, a second wash with a solution of oxalic acid may be needed to remove brown and black discoloration caused by tannins that leached out of the wood. Concentrated oxalic acid is toxic and should be handled with care.
More information: see STAIN DIAGNOSIS on ROOFS.
Preservative Treatments for Wood Shingle / Shake Roofs
There are a number of commercial treatments available to restore decay-resistance to an aging wood roof. One effective and relatively benign (to plants) treatment consists of a copper-naphthenate compound called Cunapsol 5, which is diluted 1:4 with water and can be applied with a garden sprayer. The treatment needs to be repeated approximately every five years.
More details: see WOOD ROOF COATINGS & FIRE RATINGS.
Oil-Borne Wood Roof Preservatives
Although Cunapsol 5 and similar waterborne treatments offer good protection against mold, mildew, and decay fungi, they will not do anything to slow down the cupping and splitting caused by weathering. For that, an oil-borne treatment is required. Effective treatments include copper naphthenate with a 3 to 4% metal content and copper octoate with a 1 to 2% metal content. These can be brushed on or dipped (before installation) or professionally applied with spray equipment.
Semitransparent Oil-Based Preservative Stains on Wood Roofs
Semitransparent oil-based preservative stains work well on rough-textured wood, such as shakes and shingles. They provide some pigmentation and protect the roof from decay for several years. Look for a product with both a wood preservative and a water repellent.
Stains with a high percentage of pigment provide the best protection against UV degradation. While preservative stains are best applied before installing the shingles, a surface application can significantly extend the life of a wood roof.
Treatments to Use and to Avoid on Wood Shingles and Shake Roofs
According to the Shingle and Shake Bureau, one should use only products that are marketed and labeled as a cedar roof treatment, that have an MSDS available, and that contain one or more of the following: a water repellent, UV inhibitor, or U.S. EPA-registered wood preservative. The following treatments should never be used on wood shingles or shakes:
-- Adapted with permission from Best Practices Guide to Residential Construction.
Air Vent/A Gibraltar Company www.airvent.com A complete line of roof ventilation products, including shingle-over and exposed-ridge vents with exterior wind baffles and internal weather filters. Also soffit and drip edge vents and passive and powered attic turbine-type vents.
Benjamin Obdyke www.benjaminobdyke.com Shingle-over ridge vents. Low-profile Roll Vent uses nylonmatrix. Extractor vent is molded polypropylene with internal and external baffles.
Cor-A-Vent www.cor-a-vent.com Shingle-over low-profile ridge vents, including Cor-a-vent, Fold-a-vent, and X-5 ridge vent, designed for extreme weather. Corrugated core.
GAF Materials Corp. www.gaf.com Cobra vent: roll-out shingle-over ridge vent with a polyester-matrix core 102 CHAPTER 2 | Roofing
Mid-America Building Products www.midamericabuilding.com Ridge Master and Hip Master shingle-over molded plastic ridge vents with internal baffles and foam filter
Owens Corning www.owenscorning.com VentSure corrugated polypropylene ridge vents; also passive roof vents and soffit vents
Trimline Building Products www.trimline-products.com Shingle-over low-profile ridge vents, Flow-Thru battens for tile roofs
Elk Premium Building Products www.elkcorp.com Highpoint polypropylene shingle-over ridge vents
Tamko Roofing Products www.tamko.com Shingle-over ridge matrix–type Roll Vent and Rapid Ridge (nail gun version) and Coolridge, which is molded polypropylene with external and internal baffles
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
Metal Roofing Alliance www.metalroofing.com
Tile Roofing Institute www.tileroofing.org
-- Adapted with permission from Best Practices Guide to Residential Construction.
Frequently Asked Questions (FAQs)
No FAQs have been posted for this page. Try the search box below or CONTACT US by email if you cannot find the answer you need at InspectApedia.
Try the search box just below or if you prefer, post a question or a comment in the Comments box below and we will respond promptly.
Search the InspectApedia website
HTML Comment Box is loading comments...
Technical Reviewers & References
Related Topics, found near the top of this page suggest articles closely related to this one.