hether the blame goes toglobal warming, climatechange, El Nino, urbanexpansion, careless smok-ers and campers, or some

combination of this gang of usual suspects, itis clear that wildfires can take a devastatingtoll on residential and commercial structures,destroying many thousands of buildings eachyear. The use of specialty protective coatings,however, can significantly reduce the likeli-hood or severity of the effects of fire on vul-nerable buildings.In addition, these coating materials could

gain additional prominence in protectingbuildings and properties in the line of wildfiresthat annually destroy thousands or millions ofacres of parched woodlands and brushlandsin California, other western states, and Florida. The threat of suchdamage continues to mount, as development extends further intoremote, formerly sparsely-populated areas.A launch into any discussion of flame-protection coatings

requires clarification of the terms used. ASTM E176, StandardTerminology of Fire Standards, makes several important and rel-evant distinctions, as follows.

Flame resistance: The ability to withstand flame impinge-ment or give protection from it

Fire retardancy: The ability of a paint to retard the spreadof flame over a coated substrate, usually at the sacrifice of thepaint film

Flame-retardant coating: A fluid-applied surface coveringon a combustible material which delays ignition and reduces flamespread when the covering is exposed to flame impingement

Fire-retardant coating: A fluid-appliedsurface covering on a combustible material whichdelays ignition and combustion of the materialwhen exposed to a fireBased on these definitions, it can be conclud-

ed that fire-protective coatings possess at leasttwo important properties: First, prevention ordelay of ignition and combustion of the substrate,and second, limitation of the amount or rate offlame spread.These separate functionalities are reputed to be

provided by the various commercial coatings onthe market. When applied to non-combustiblematerials such as steel beams, the objective, obvi-ously, is not to prevent combustion, but rather tolimit thermal weakening of the structural memberand heat transfer to combustible materials. Fire-retardant products are typically applied to com-

bustible materials, and are applied like paints by brush, roller, orspray. Fire-resistant coatings are applied in much greater thickness-es and are generally sprayed or troweled to delay heat penetrationthrough a substrate.Most light-commercial and residential buildings, and some indus-

trial structures, are of the “wood-stick” framing type of construction,and additionally involve the use of potentially combustible claddingand insulation materials such as foam. In addition, the widespreaduse of engineered-wood products such as glue-lam beams and truss-es, sandwich panels, plywood, and OSB (oriented strand board)provide good sources of combustible fuel.So how does the fire retardant work? Although some specialized

technologies exist, the majority of fire-protective coatings work byreducing the flammability of materials by either blocking the firephysically or by initiating a chemical reaction that stops it.

W

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Passing the testAllen Zielnik

Atlas MaterialTesting

Technology LLC

Specialized coatingstechnologies canboost protectionof buildings and

properties in the lineof forest, brush fires

Where there’ssmoke, there

may be wildfire

D u r a b i l i t y

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http://www.quantumcoatings.com

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Physical retardancy• Chemical reactions that cool the materials• Formation of a protective layer• Dilution and release of water vapor or gas to restrict or extin-guish the fire

Chemical retardancy• Gas-phase reactions such as the release of halogens likebromine or chlorine• Char formation to create a carbon layer• Intumescence, or expansion and formation of an insulatinglayer under the surface char

Testing and evaluating fire-resistive coatingsSo how are fire-preventative or fire-resistive coatings tested andevaluated? The primary specified test is ASTM E84, StandardTest Method for Surface Burning Characteristics of BuildingMaterials. This test is frequently referred to as the “Steiner tun-nel” test for surface flame spread and smoke generation.Developed by Al Steiner for testing building materials such aswood or gypsum board at Underwriters Laboratories in 1944,

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the Steiner tunnel test has been standardized by the major NorthAmerican standards-writing organizations (ASTM E-84, NFPA255, UL 723, ULC S102) and widely incorporated into everyNorth American building and fire code.The test procedure makes use of a 25-foot-long, vented tun-

nel, lined with firebrick, with the test material mounted to the topof the chamber. At one end of the chamber, the sample is sub-jected to a high-energy flame for ten minutes. Flame spread isdetermined visually through windows built into the tunnel, anda light meter measures smoke density. These tests have alsobeen adopted by the International Code Council in AC363,Acceptance Criteria of Surface-Applied Fire-RetardantCoatings.

Test class ratingsASTM E84/UL-723 class ratings are determined from burn tests ofthe coating on two reference material substrates, red-oak lumberand asbestos cement board, which are assigned values of 100 and0, respectively. The test material is assigned a burn rating relativeto these numbers. For example, a material that burns twice as fastas red oak would be given a flame spread rating of 200.

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Class Flame spread“A” or I 0-25“B” or II 26-75“C” or III 76-200

Remember, this rating applies only to aspecific, single component such as a paintfilm. Most properly applied fire-retardantcoatings typically reduce the flame spread to25 or less, and fall into the Class A catego-ry, with top-performing products in the 5-10range.A similar smoke-density rating system is

applied for smoke generation. A smaller lab-oratory version of the Steiner test is definedin ASTM D3806, Standard Test Method ofSmall-Scale Evaluation of Fire-RetardantPaints (2-Foot Tunnel Method). The E84method, however, has become the de factospecification requirement. Interior large-scaleroom corner burn test methods also exist, butonly a few manufacturers have this type oftest data available for comparison.Architects and construction specifiers may

be familiar with hourly ratings for the fireendurance of products and materials; these,however, apply to the ability of an assemblyto prevent the spread of fire between spaceswhile maintaining structural integrity.Therefore, these ratings apply to assembliessuch as doors, walls, ceilings, etc., but not tosingle components such as coatings. It shouldalso be noted that some flame-retardantpaint additives are sold that can be added tocoatings; the effectiveness of these productsmay vary, however.It should be kept in mind that standard

tests such as the Steiner tunnel test representartificial conditions that may not be preciselyrepresentative of actual conditions in thefield. To empirically illustrate the perfor-mance of their products, several of the majormanufacturers of fire-protective coating sys-tems also provide anecdotal information,often in the form of informative video demon-strations, of actual structural burn tests. Whilequalitative in nature, these demonstrationscan often provide the architect or builderwith supporting information about the effec-tiveness of products under consideration.Fire-protective coatings are most effective-

ly used in a whole-building approach. This

involves the application of protective coat-ings on all combustible surfaces during theconstruction phase, including structuralframing, joists, and the back side of interiorsurfaces, such as paneling, flooring, andwallboard, as well as the building exterior.The use of a total-building approach can

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reduce the amount of fire damage or delayfire spread to allow time for primary fire-fighting activities, an important attribute inless-developed, more-remote areas.Fire-protective coatings are currently avail-

able in a variety of forms, from latex paint tostains and clear varnishes. When properly

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applied by factory-certified applicators, theuse of these coatings may qualify the ownerfor insurance-rate discounts. In some cases,a similar level of protection, but at reducedcost, can be achieved with these materials incomparison to dry sprinkler systems. Ofcourse, even where economic incentives donot apply, the opportunity for minimizingpotential risks to occupants should be animportant consideration, especially forschools, clinics, nursing homes, public build-ings, etc.Not all fire-protective coatings are suit-

able for weatherable exterior use, however.As with any coating, the potential for UV-and moisture-induced degradation canreduce fire-resistance properties or causecoating failure such as delamination. Not allmanufacturers provide field data to supportproduct claims, so the architect or specifiershould require some proof of weatherability.Those manufacturers that do supply perfor-mance documentation typically offer a five-year product warranty.In addition to the primary fire-protective

properties, some coatings systems alsoincorporate biocides for mold and mildewprevention. At least one manufacturer ofsuch dual-purpose coatings has teamed witha mortgage lender to offer a discount onloans for new construction.

The marketplaceSeveral dozen manufacturers offer variousfire-protective coatings, and a number ofmanufacturers specialize in this type of tech-nology with a product line. Specializedmanufacturers of note include FireFreeCoatings, Flame Control Coatings, HyTechThermal Solutions, NoBurn Inc., andUniversal Fire Shield. Some of the majornational and regional paint and coatingscompanies also offer products of this type.As with all coatings, these products are

subject to environmental and regulatoryissues involving VOC content, so theprospective coating should be evaluated toensure it is suitable and authorized for thegiven application and location.Qualifications for points under the LEED(Leadership in Energy and EnvironmentalDesign) rating system or otherwise “green”certified coatings should taken into account.In considering fire-retarding or fire-resis-

tive performance, the specifier or usershould aim for “Class-A” rated fire protec-tion and the lowest (best) flame-spread num-ber. For interior applications, a correspond-ing smoke-density rating of 50 or less shouldbe the objective. The manufacturer shouldstate that the product is appropriate for spe-cific substrates, as a variety of formulationsare typically offered. The potential for insur-ance discounts should be investigated, asshould a determination of whether the appli-cation must be done by certified contractors.Also meriting attention are the benefits ofdual-purpose coatings that incorporate moldinhibitors.In general, the greater the number of

independent laboratory certifications, testdata, and application case studies, the bet-ter the confidence the user will have in theprotection capabilities of the product. Inquiryshould also be made about service war-ranties, reapplication expectations, andinsurance-premium discounts, as well as ini-tial product cost. And remember, these prod-ucts perform against fires started insidebuildings, too, and not just against the wild-fire roaring through parched forests orbrushlands.

Albi Mfg.Over 50 Years of

Superior Fire Protection!

Albi Manufacturing,Division of StanChem, Inc.

860/828-0571 • www.albi.com

Albi Clad FP

• Ideal for historic preservation andnew construction.

• Up to 2 hours of fire protectionfor interior wood, wallboard, andother substrates.

• ULI listed.

Albi Clad TF

• Ideal for interior structural steel.

• ULI listed for up to 3 1⁄2 hoursprotection.

Albi’s thin-film, lightweight,water-based intumescent fireprotection offers attractive finishesfor commercial buildings withoutcomprising safety. Our attractivefinishes conform to substratecontours while meeting buildingcodes and insurance requirements.

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Room-corner burn demonstration for fire-resistive coatings: Inthe left structure, the chair and drapes were treated with a fire-retardant material and the walls were treated with an intumes-cent fire-resistive latex paint. The structure on the right was

untreated. Photo courtesy of NoBurn Inc.

http://www.albi.com

KEIM Mineral CoatingsFor over 125 years, KEIM mineral coatings have decorated and protected thousands of structures. From recent coatings on The White House, Arling-ton House and Hearst Tower to others 100 years later, KEIM coatings maintain their original beauty.

KEIM’s unique potassium silicate binders combined with pure mineral pigments form a microcrystalline structure inherently similar to mineral substrates. Mineral pigments are lightfast, unaffected by UV or weather. A coating of KEIM lasts a long time.

KEIM coatings penetrate the substrate to protect from weather, pollution, mold and carbonation.

The microcrystalline structure freely breathes out vapor yet is water repellent. Dirt washes away with the rains, leaving buildings bright and clean for decades.

Indoors, healthy air is maintained without biocides. Freely breathing, water cannot accumulate on the coating. And with VOC’s less than 1 g/l, those chemically sensitive are not disturbed. The crystal-line structure is highly abrasion resistant so it can take multiple cleanings.

For lasting beauty, specify KEIM mineral coatings.

natural ingredientsenvironmentally safeeconomical, lasting for decades

KEIM MINERAL COATINGSof America, Inc.

10615 Texland Blvd # 600Charlotte, NC 28273USA

Toll Free 866-906-5346Tel 704-588-4811Fax 704-588-4991

www.keim.com • keim-info@keim.com

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http://www.keim.com