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ROOFING INSPECTION & REPAIR
AMERICAN CEMWOOD ROOFING
BEST ROOFING PRACTICES
BUILT UP ROOFS
CATHEDRAL CEILING VENTILATION
CERTIFICATIONS for ROOFING CONTRACTORS
CHIMNEY FLASHING Mistakes & Leaks
COLD WEATHER ROOF TROUBLE
DECKS, ROOFTOP CONSTRUCTION
EPDM, RUBBER, PVC ROOFING
EXTRACTIVE BLEEDING on SHINGLES
FIRE RETARDANT PLYWOOD
FLASHING on BUILDINGS
FLAT ROOF MOISTURE & CONDENSATION
Green House or Solarium Roof Leaks
HEAT TAPES & CABLES on Roofs for Ice Dams
ICE DAM PREVENTION
MASONITE WOODRUF FIBERBOARD ROOFING
NOISE CONTROL for ROOFS
PLASTIC ROOFING TYPES
PVC, EPDM, RUBBER ROOFING
ROOF ARCHITECTURAL STYLES - PHOTO GUIDE
ROOF CLEANING RECOMMENDATIONS
ROOF COLOR RECOMMENDATIONS
ROOF INSPECTION SAFETY & LIMITS
ROOF LEAK DIAGNOSIS & REPAIR
ROOF NOISE TRANSMISSION
ROOF REPLACEMENT SNAFUs
ROOFING FELT UNDERLAYMENT REQUIREMENTS
ROOFING MATERIALS, Age, Types
SADDLE CONSTRUCTION at CHIMNEYS
SNOW GUARDS & SNOW BRAKES
STANDARDS for ROOFING
STRESS SKIN INSULATED PANELS
TEST LABS - ROOF SHINGLE
TREES & SHRUBS, TRIM OFF BUILDING
TRUSSES, Floor & Roof
UNDERLAYMENT REQUIREMENTS on ROOFS
VENTILATION in BUILDINGS
WALK-ON ROOF SURFACES
WARRANTIES for ROOF SHINGLES
WORKMANSHIP & ROOF DAMAGE
Coatings for wood shingles or wood shake roofs - wood roof preservatives, wood roof fire resistive coatings: This article explains fire resistant treatments and preservative treatments for wood shingle or wood shake roofing in historic and contemporary use.
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Protective Coatings & Treatments for Fire Rating for Wood Shingle & Wood Shake Roofs - Getting from No-Rating to B-Rating to Class A Fire Rating
More details useful for determining the condition of a wood roof are at WOOD ROOF INSPECTION GUIDE. More about wood coatings and about cleaning wood shingle or shake roofs is found at WOOD ROOF MAINTENANCE. Also see Wildfire Damage Prevention.
Types of Wood Shingle/Shake Roof Treatments Available
As we mention in our outline of roofing materials and their properties found at ROOFING INSPECTION & REPAIR, wood shingle roofs, 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.
NRCA's David Flickinger explained in 1999 in Professional Roofing, that treatments are available for wood shingles and wood shakes on building roofs to preserve the wood from rot and to increase its fire resistance. For new wood shingles, a pressure treatment impregnates the shingles with a wood preservative (in the 1990's CCA or chromated copper arsenate) or a fire retardant.
When shingles are treated with a fire retardant they are then heated to complete that treatment procedure.
Typical spray or brush-on wood roof treatments are also available to treat wood shingles or shakes that have already been installed on a building.
According to Flickinger, the Cedar Shake & Shingle Bureau (CSSB) recommends that cedar roofing products used in locations with high decay potential should be treated with a preservative.
A U.S. map provided by the Forest Products Laboratory (above-left) indicates that the southeastern quadrant of the U.S., but extending north into West Virgina and parts of eastern Kentucky and Tennessee make up this area of high decay hazard (the dark colored area on the map) based on the FPL climate index.
Questions About the Durability of Fire Retardants & Preservatives for Wood Roofs
According to the NRCA both of the wood roof processes described above, when wood roofing shingles or shakes are treated under pressure, before installation on the roof, are considered "permanent", that is, the treatment should last for the life of the wood shingle.
For existing wood shingle roofs, treatment might be applied using a topical spray or brush-on of preservatives. These treatments are not permanent and need to be performed periodically depending on the geographic locale of the roof
A bit before Flickinger's 1999 article, in 1995 in his article on Choosing Roofing, Jefferson Kolle questioned the durability of wood shingle fire retardant treatments. Kolle suggested that rain tends to draw the fire retardant to the shingle surface where it is washed away over time.
The same article however, quoted Don Meucci from the Cedar Single & Shake Bureau who said that tests performed on fire-retardant-treated wood shingles from a 16-year old roof passed the current fire resistance tests of that time. Nonetheless, some communities where fire risk is particularly high (Los Angeles California, Newcastle, New Hampshire) have banned the use of wood roofs regardless of their treatment.
For added details about proper wood shingle or wood shake roof installation, perhaps the most authoritative source of wood shingle and wood shake information is from the Western Red Cedar Shingle & Shake Bureau (now the Cedar and Shake Shingle Bureau, since not only western red cedar is used for roof shingles).
Sources of Wood Roof Fire Retardant Coatings - where to buy
Frequently Asked Questions (FAQs) about the fire rating of wood shingle or wood shake roofs & about wood roof coatings to improve fire rating & fire resistance
Questions & answers or comments about preservative coatings & fire resistive coatings used on wood shingle roofs.
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Technical Reviewers & References
Related Topics, found near the top of this page suggest articles closely related to this one.