+ + DD A D+D eResource FIRE-RESISTIVE COATINGS Photo courtesy of The© Gallery 2011-2014 at Westbury Technology Plaza, Publishing Garden Co. City, NY i + FIRE-RESISTIVE COATINGS Copyright 2011 by Technology Publishing Company 2100 Wharton Street, Suite 310 Pittsburgh, PA 15203 All Rights Reserved This eBook may not be copied or redistributed without the written permission of the publisher. © 2011-2014 Technology Publishing Co. ii Contents iv Introduction 1 Fighting Fire with Fire Protectives by Allen Zielnik, Atlas Material Technology LLC 7 Intumescent Coatings in Interior Spaces: Functional Aesthetics by Allen Zielnik, Atlas Material Technology LLC 11 Intumescent Casting Technology Takes the Heat D+D, June 2013, Bill Dempster, International Paint 15 Fire Test Methods D+D, September/October 2012, Terry Viness & Tom Remmele, Sto Corp. 17 Sentinels of Safety: Fire-Resistive Systems Stand Ready to Serve A D+D Online Feature published September 12 2011, Walter Scarborough, HALL Building Information Group © 2011-2014 Technology Publishing Co. iv Introduction This eBook features articles from Durability and Design (D+D) about fire-resistive coatings and includes topics such as intumescent coatings in interior spaces, fire test methods and more. All information about the articles is based on the original dates of publication of these materials in D+D. Please visit www.durabilityanddesign.com for more articles on these and other topics. © 2011-2014 Technology Publishing Co. 1 Fighting Fire Spray-applied fire-resistive materials, or SFRMs, insulate steel during fires, helping to delay temperature rise with Fire Protectives and the resulting decrease in structural strength. Here, Modern intumescents have advanced a gypsum-based SFRM has significantly in both fire performance been applied to steel ceiling beams at the “Red Building” and aesthetics. in West Hollywood. Photo courtesy of Isolatek By Allen Zielnik, Atlas Material Testing Technology LLC International. hemical flame retardants have been used since the may have had some appearance issues such as orange peel, time of the Romans, who reportedly used solutions modern intumescent coatings, which insulate the underlying of alum and vinegar to prevent warships and siege materials from temperature rises by forming a solid-phase towers from catching fire. The search for and use char, have significantly advanced in both fire performance and of fire-protective materials, chemicals and coatings aesthetics. Ccontinues to this day. While some of the chemicals used over Advances in intumescent coatings systems mean that the years have since proven harmful to health or the envi- today’s modern architectural design and color palette are no ronment, today’s products, particularly the non-halogenated longer limited by fireproofing requirements. flame retardants, are considered essential for helping to protect lives. Parsing Fire-Retardant vs. Fire-Resistant Coatings Especially in large public buildings, building codes increas- Two classes of fire-protective products are in use today, and ingly require fire-retardant coatings, particularly intumes- the distinction is worth noting: cents. They can significantly reduce flame spread and toxic • A fire retardant is a chemical that endows a treated material smoke generation while extending the performance of steel with the ability to slow the spread of flames, particularly verti- reinforcements in a fire situation, to allow additional egress cal fire spread, and to delay flashover, thus allowing more time time and emergency first response. While early products for evacuation and firefighting. © 2011-2014 Technology Publishing Co. 2 Most thin-film intumescent coatings are made for interior use only. Here, a certified applicator installs a thin-film intumescent coating to wooden first-floor framing on a residential project. Photo courtesy of No-Burn Inc. Many classes of chemicals are used as fire protectives, but the prime considerations are the properties. If one were A painter uses an airless sprayer to apply a thin-film intumescent to make a “top 10” list of desirable fire-protective coatings coating to the steel beams of a manufacturing facility. Intumescent properties (or, in this case, a “top 9” list), it might include the coatings generally can be applied during construction. following: Photo courtesy of Shield Industries Inc. • Provide long-term thermal and ignition protection from heat and flame; • A fire resistant is a material that is inherently resistant to • Have a low flame spread rate; fire penetration; they are commonly used in wall and ceiling • Produce little or reduced amounts of smoke and toxic gases; assemblies. • Be durable under normal environmental exposures; Both are considered passive fire protection and are usually • Have good wear resistance and maintainability; used in combination with active protection, such as sprinkler • Have and retain good aesthetic properties (for exposed systems. In either case, the primary purpose is to prevent the surfaces); passage and spread of smoke and flame from one area of the • Be easy to apply, maintain and repair; building to another and to allow building occupants a safe • Be low in VOCs and odor; and escape. Secondarily, they prevent or reduce the amount of • Be cost-effective. damage to the building and neighboring structures, and they reduce the risk of structural collapse to give more time for Protecting Steelwork with SFRMs emergency response. Most modern office, multi-unit residential and large construc- Fire retardants can act by any of several methods. First, they tion projects, such as airport terminals, convention centers, can act chemically to interfere with the free radical reactions public buildings and sports venues, use steel frame construc- that occur during combustion or, as intumescents do, to tion. Structural steel weakens when exposed to temperatures insulate the underlying materials from temperature rises by 750 to 1,100 F (400 to 600 C). Therefore it is important to forming a solid-phase char. Secondly, they can act physical- protect the steel to help prevent or delay structural collapse. ly to lower the temperature through heat-releasing (endo- This steel framework typically is concealed behind walls and thermic) reactions, or to slow the fire spread by diluting the ceilings, where good appearance is not a factor. Designers oxygen with non-combustible gases. Lastly, they can provide often protect this framework during construction by covering an impervious surface layer to keep oxygen from reaching a it with an economical fire-resistant cementitious or similar ma- flammable substrate. terial, known as a spray-applied fire-resistive material (SFRM). © 2011-2014 Technology Publishing Co. 3 Intumescent coatings generally require three components: a source of carbon, a blowing agent and an acid catalyst. The resulting char is a low-density cellular insulating structure with low thermal conductivity. Binder chemistry formulation is especially critical with intu- mescent coatings. In addition to the usual coating functions, the binder must contribute to the formation of a uniform char structure, since the molten binder helps trap gases emitted by the decomposing blowing agents. That helps to provide an even expansion of the char. The binder must help resist abrasion and damage during construction and in-service use by providing the necessary hardness, and provide any nec- essary protection from UV and moisture, which can damage the intumescent ingredients. The binder also must provide the desired gloss level and flow-leveling to resist orange peel On contact with flames, here 1,000 F to 1,200 F (538 C to 649 C), a wa- appearance. ter-based intumescent paint forms a dense, protective layer, or “char.” Low- or zero-VOC waterborne acrylic systems comprise Photo courtesy of Paul Pisarski of Flame Control Coatings. a large segment of the market, although polyurethane, two-component epoxy and other products are available. The SFRMs typically include ingredients such as mineral wool, epoxies are sometimes perceived as better than water-based cement and gypsum. These are viscous products that are products in terms of aesthetics and durability. Intumescent spray-applied at least a half-inch thick. This coating helps coatings do need a high film build, and many products require insulate the steel, delaying temperature rise and the resulting two coatings; the water-based products will have a longer dry structural weakness. One drawback is that these coatings are time for installation. As the proper film thickness is critical sensitive to damage during construction. for functionality, certified installers often must perform field application or the application must be inspected for compli- Protecting Exposed Surfaces ance. The application method is product-specific, with most with Intumescents Modern architectural design, however, often includes large expanses of exposed steel where a thick, lumpy and unattractive cementitious material is not aesthetically acceptable. In many cases, the exposed steel is itself a major decorative design el- ement. In these cases a “thin film” intumes- cent coating, first commercialized in the 1960s, is the go-to solution. Protection of structural steel remains the largest market for thin-film intumescents. They are also used for rising commercial, multifamily and residential markets that include combus- tible building components like structural insulated panels, spray foam insulation, engineered wood framing and architectural woodwork. Thin-film