Curling wood shingle roof (C) Daniel Friedman Wood Shingle & Wood Shake Roof Protective, Preservative & Fire Resistant Coating Guide
     

  • WOOD ROOF COATINGS & FIRE RATINGS - CONTENTS: Fire resistant treatment for wood shingle & wood shake roofs. Wood preservative treatment for wood shingle/shake roofs. Wood shingle roof inspection, failures, repair, product defects. Key design details & references for preservative coatings & fire resistive coatings used on wood shingle roofs.
  • FIRE RATINGS for ROOF SURFACES - separate article
  • POST a QUESTION or READ FAQs about preservative coatings & fire resistive coatings used on wood shingle roofs
  • REFERENCES

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

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.

Green links show where you are. © Copyright 2015 InspectApedia.com, All Rights Reserved.

Protective Coatings & Treatments for Fire Rating for Wood Shingle & Wood Shake Roofs - Getting from No-Rating to B-Rating to Class A Fire Rating

US FPL climate index for the US 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.

[Click to enlarge any image]

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

According to Best Practices Guide to Residential Construction and discussed in BEST ROOFING PRACTICES,

Where premium red or white cedar is too expensive for a particular roofing job, wood roof buyers should consider pressure-treated southern yellow pine shakes and shingles. In its favor, yellow pine is a tougher and stronger wood, and although not as pretty as red cedar when new, over time they will both weather to a similar silver gray.

Because penetration of the treatment on pine roofing shingles is nearly 100%, pressure-treated pine shingles carry guarantees against decay for up to 50 years, making them well suited to high-moisture environments, shallow slopes, and shady wooded sites where organic matter may collect on the roof. The preservatives should not leach out over time.

One drawback to yellow pine shingles and shakes is that many are flat-grained, so most come pretreated with a water repellent to help them resist cupping and splitting. However, retreatment with a water repellent at some point may be required for optimal performance. Western red cedar shingles are also available pressure-treated for severe applications where standard cedar shingles are prone to decay.

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

  • Fire Retardants Inc., 123 Columbia Court North, Suite 201, Chaska MN 55318, Tel: 800-913-9385, email: info@fireretardantsinc.com, Website: www.fireretardantsinc.com
    The company produces Burn Barrier No. 10 Shingle Treatment, Clear, Fire Retardant solvent-based wood roof coating, fire hazard hazard classifcation Class "B"
  • Carboline Fire Protective Coatings, Carboline Company 2150 Schuetz Road St. Louis, MO 63146 Phone: 1-314-644-1000, Tel: 800-848-4645 website: www.carboline.com
  • Flame Safe Wood Products, Flame Safe Chemical Corporation and Flame Safe Wood Products, Inc. 2653 Warfield Avenue, Fort Worth, Texas 76107 Phone: 817-740-9197 Toll Free: 1-800-333-9197, website: www.flame-safe.com/
  • Contact us to add product listings, no fees, no conflicts of interest are involved

More Reading

Green link shows where you are in this article series.

...




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

...

Ask a Question or Search InspectApedia

Questions & answers or comments about preservative coatings & fire resistive coatings used on wood shingle roofs.

Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Search the InspectApedia website

HTML Comment Box is loading comments...

Technical Reviewers & References

Publisher's Google+ Page by Daniel Friedman

Click to Show or Hide Citations & References