Coatings At Their Best As the coatings market grows, building owners will have improved selections of their arsenal of applications. By Pete E. Rowan, BS, C.P.M.R. Is there a Liquid applied EPDM roof coating? Interestingly, there is a very successful product in the roofing and RV business. Currently, there is only one coating system offered as a field-applied product that uses lower molecular EPDM as the base binder component. According to Greg Ross with Lion Elastomers, Lion Elastomers, which grew out of the elastomer operations of Uniroyal Chemical and DSM, is a leading manufacturer of rubber products. The company manufactures product in two world-class facilities for ethylene-propylene-diene(epdm) and styrene-butadiene(sbr) elastomers. Royalene EPDM is used in a wide variety of applications that require superior heat, ozone and chemical resistance, excellent long-term aging and outstanding exterior weathering. Royalene applications include automotive, industrial and consumer hoses, weather seals, molded goods, wire and cable insulation, window profiles, roof sheeting and thermoplastic elastomers. Trilene liquid EPDM is a lower molecular weight elastomer having the characteristics of conventional EPDM. It represents a class of specialty lower molecular weight EPDM product used in roof and water-proofing coatings, adhesives, caulks and sealants, gear oils and greases, rubber goods and many other applications. Conventional Trilene elastomer used in coating applications is formulated into solvent-based products. Trilene 65 EPDM has been used in roof maintenance coatings for many years, and recently Lion Elastomers announced the development of Trilene 65D, a waterdispersed version of this polymer. With its random structure and side chain unsaturation for crosslinking, Trilene 65D has the same thermal and oxidative stability, and mechanical properties as the original Trilene 65, with the ability to make low/no VOC coatings, adhesives, caulks and sealants. A finished goods formulator for the EPDM-based product is Pro Guard Coatings, Inc. Pro Guard Coatings, formerly Best Bros. Paints, has experienced tremendous changes since its beginning in 1950. The company s initial emphasis was on the production of house paints and later into specialty coatings. Specialty coatings dominate their present product mix, with emphasis on Liquid EPDM, Epoxies, Urethanes and UV Curable Coatings. Helmar Gueldner is the owner and inventor of the process created to use Trilene as a viable liquid applied roofing coating system. Pro Guard s products are, according to Gueldner, 90 percent identical to heat vulcanized EPDM membrane s, we can expect the two forms to have very similar characteristics. Gueldner created the process with a chemist at Uniroyal Chemical almost 30 years ago. Since then, Liquid Roof has been sold as one of the largest coatings providers to the Recreational Vehicle industry and coated many flat roofs, metal roofs and different substrates all around the world. Unique Coating Characteristics The characteristics of this coating are unique compared to acrylic, silicone, polyurethane and other coatings designed to coat roofing membranes. According to Gueldner, The secret is in the process as well as the way the component chemicals are put together. The final cured film properties will always be the same regardless of length of time or conditions after application. Liquid Rubber and Liquid Roof use peroxide cure achieving properties just like the heat vulcanized EPDM, but it will react down to 50 F. In fact, it will wait to react if it is colder until the outside temperature gets back to 50 degrees. The finished product has great physical characteristics. Moisture vapor penetration rate of under-five perms. 1000 psi tensile strength and a 65 percent elongation rate on an aged roof. This product has passed many ASTM tests and is cool roof rated. Also, it withstands extreme temperatures. In many cases only one coat is needed. It is delivered at 68 percent solids content. The recommended application rate is 25 dry mil, but can be applied up to 40 mil in a single pass. A primer is recommended on asphalt roofs and severely degraded substrates. The coating can be used on rusty metal without a primer. Since it is hydrophobic with a very low 36 METAL ROOFING AUGUST/SEPTEMBER 2017
moisture vapor penetration rate and non-dielectric, there will be no further rusting of the metal roof substrate. For similar reasons, the coating is sold as a pond liner. It can be pigmented to any shade as the base is white, not clear. It takes several days to completely crosslink. Once the solvents have evaporated it is fine for rain, usually around 12-24 hours after application depending on the temperature. Pro Guard makes a low VOC version using an exempt solvent for VOC compliance. The substrate must be dry because the coating formulation is very hydrophobic. Coating in an area known for ponding on a roof is fine as long as there has been a study to make sure the insulation is not wet. The coating will swell EPDM sheet when applied directly to it, which enhances adhesion. After the solvent has dissipated the EPDM membrane relaxes. On some substrates, like PVC and TPO, a very light bonding primer is recommended. U.S. Coast Guard Completes Coating Of Their Metal Roof The first example is the Coast Guard Coast Guard building roof in Ocean City, Maryland. building in Ocean City Maryland. In 2015, the U.S. Coast Guard completed coating of their metal roof with Liquid Rubber. The general contractor was Edgewater Construction of Chesapeake, Virginia. Bill Washborn was the project
manager. He used certified applicator, Dome and Roofing Solutions, owned by Lars Benson. The project called for a 17,000-square-foot standing seam metal roof coating. They used Liquid Rubber that was tinted to Coast Guard Blue. The Liquid Rubber was applied to the roof using a truck mount sprayer. The product was distributed by EPDM Coatings, an authorized distributor of Pro Guard Coatings. The end result is a liquid applied EPDM membrane that will resist the tremendous salt water degradation near the ocean. Northside Distribution Project Successful Our primary case study takes us to Spring, Texas. Northside Distribution needed to coat the top of their building and they wanted to get into the roof coating business as a distributor. They took me to the top of their building and there were metal buildings as far as the eye could see! Their building has a 30,000-square-foot steel standing seam roof. According to the general manager, I liked the fact that we could apply just one coat. They spent a few days pressure washing, repairing and adding a few rows of screws for strength. To get into the business they purchased a lift 38 METAL ROOFING AUGUST/SEPTEMBER 2017
The project called for a 17,000-square-foot standing seam metal roof coating. Liquid Rubber tinted to Coast Guard Blue was used. and a new Graco pump with 250 feet of hose. A factory representative was there to train the applicators. Their operations manager and applicator were very good and learned that they had sprayed many roofs in the past. It was early March. Temperatures were a balmy 75 degrees in Houston. There was low humidity. Spraying the Liquid Rubber coating requires a dilution of one gallon of xylene to five gallons of Liquid Rubber. To start, the operator set up his spraying rig on the ground. The man on the ground was responsible for mixing the product and pouring in the catalyst. The operator used a 3/8 drill with a large squirrel cage mixer to bring thicker material into the blend, then slowly poured in the xylene. This creates a vortex. Once the material is mixed for about three minutes the catalyst is poured into the vortex and mixed for another three minutes. The pot life Northside Distribution building roof, in Spring, Texas. WWW.METALROOFINGMAG.COM 39
is between 30 minutes and an hour. The roof was measured to make sure that the proper amount of gallons were used to achieve a 25 dry mil thickness. Good communication between the operator and applicator allowed the correct thickness to be applied after the first couple of panels. Then it was easy to repeat the process over the entire roof. It took five days to spray Graco spray pump. the roof. The lift made it much easier to go up and down than ladders or a scissor lift. While I was there the first couple of days, the lift was used a lot to make sure everything was going well and taking potential customers to see the process. In this case no back rolling was necessary as the product is self-leveling by nature. They decided to apply a thicker coat at the base of the roof near the drip line and at the peak of the roof. In several locations, seaming tape was used. They used a butyl based tape so the coating would stick. It is important, like any spray operation, to have a good paper wall to catch any drift and overspray of product. On a windy day material can float a long way. There was a small issue with drift, but that was quickly resolved with calmer weather. The applicator came out of the paint spraying business. It took a while for him to spray without the whip at the end of each pass. Keeping the spray angle directly facing the roof at all times improved application. At the end of the day the equipment was flushed with xylene to remove the residual coating from the lines and clean the sprayer. The material does not harden in the lines because it needs air to cure. This job took a total of 11 days from start to finish with two men, including a couple days lost because of rain between the cleaning and application. Goals Ultimately Met Their goals were met by creating a dry warehouse, reducing the energy consumption in the building by using a cool roof rated product, and providing a base case for Northside s future distribution business. In conclusion, EPDM has been one of the most reliable products in the roofing industry for many years. As the coatings market grows, building owners will have a good choice by adding liquid applied EPDM to their arsenal of choices and potentially other coating suppliers will produce liquid applied EPDM in the future! Rowan has 35 years of experience in the coatings industry in manufacturing, contracting and distribution. He was the national sales manager at Pro Guard for four years. He currently is the president of his own manufacturers representative company and can be contacted at www.coatingsandfinishes.com or 301-221-0468. MR 40 METAL ROOFING AUGUST/SEPTEMBER 2017