Get Into The Ooze

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Get Into The OozePreventing building deterioration through the use of coatings and sealants

By Elaine Foxwell

Whether the culprit is UV light, the corrosive effects of climatic pollution, or oxidation from snow and rain, self-storage buildings degenerate over time from exposure, resulting in a loss of value. To literally shield your investment, experts recommend a vital maintenance plan involving the use of sealants and coatings.

In a report on the North American sealants market by Frost & Sullivan, a global market-research company, a sealant is defined as “a liquid, paste or foam material that, when applied to a joint or orifice, forms a tight seal against liquids or gases.” The report identifies nine “major” and nine sub-classified sealants. Each has its own composition and properties and is effective for different applications.

With so many types of sealants, facility owners may be at a loss to decide which is best for particular repairs. Storage buildings, most of which are metal, expand and contract. To be effective, sealants need to be elastomeric as well as have structural strength. But why and how do sealants fail?

“Water ingress will undoubtedly be the major cause of structural degradation of a building, not to mention the No. 1 cause of consequential damage claims for ruined contents of occupied spaces,” says Lester Hensley, president of Emseal Joint Systems Ltd. in Westborough, Mass. Emseal supplies preformed foam and mechanical expansion joints.

Roof-Coating Systems

The majority of existing commercial roofs are metal, built-up, single-ply membranes and polyurethane foam. There are different methods of repairing and maintaining these substrates, and it is important building owners consult someone experienced with their specific roof, says Dave Kessler, director of operations for Uniflex Roofing Systems LLC. The Medina, Ohio-based company manufactures a complete line of roof coatings and accessory items designed to waterproof existing buildings.

Aluminum and elastomeric are the two primary coating systems specified for metal. Facility owners should ask the contractor or manufacturer for references specific to their substrates, as larger problems can be created if incorrect materials and methods are used for repair. Whoever works on the roof should have the proper insurance, equipment and experience in the installation of materials. “The product is only as good as the application. If the prep work is not done properly, a roof failure is imminent,” Kessler says.

Roof-coating systems range in cost from $1 to $2 per square foot, depending on the existing condition of the roof and amount of work needed. Before hiring an applicator, building owners should do some basic research. Kessler says to consider how long a company has been in business; its history of experience and references with your type of roof substrate; whether it has proper insurance with a rated insurance carrier; estimated length of project time; and type of warranty, if offered.

“A high-quality roof-coating system includes a biodegradable cleaner to prepare the surface metal, industrial-grade caulk for repairs at seams and protrusions, and an elastomeric coating made from 100 percent acrylic resins,” says Clint Whitsett of United Coatings, a Greenacres, Wash.-based manufacturer of water-based, 100 percent acrylic elastomer. “The added benefit of an acrylic roof coating is it will remain flexible, allowing the metal to expand and contract with fluctuations in temperature.”

Application. Prior to the application of a coating, the roof must be thoroughly cleaned, all mechanical fasteners checked for integrity; and rust removed, says Whitsett. The elastomeric basecoat should be applied at a minimum of 1 gallon per 100 square feet. After the basecoat is dry, a topcoat is applied, also at a minimum of 1 gallon per 100 square feet.

The coating should be applied by airless spray, using a multipass technique to ensure even application to all sides of the metal-panel corrugation. It is important to apply coating into crimped or pre-sealed vertical (side-lap) seams that have not been detailed. The minimum basecoat/topcoat dry-film thickness required at any location is 15 mils, generally for a five-year product warranty. For extended coverage periods, additional coats and heavier film builds will be required, Whitsett says.

A good roof coating will cover an average of 60 to 100 square feet per gallon for the first coat and 100 to 150 square feet per gallon for the second. Walls and doors with good pigmented direct-to-metal (DTM) latex will average 250 to 350 square feet per gallon. Some surfaces may need two coats for complete coverage. Good roof sealants should last five to eight years; exceptional-quality products can last as long as 15 years. Good-quality DTM paint will last three to five years.

Maintenance and Inspections. Rick Dodge, vice president of sales and operations for Rib-Roof Metals Inc., a Rossville, Tenn.-based manufacturer of roofing and building systems for the self-storage industry, suggests regularly inspecting roofs for cracks and bubbles in the sealants, particularly in exposed areas. Though Galvalume-coated steel has become the major material used in metal roofing, roofs still sustain damage from the elements. Regular maintenance is required to keep them functional and attractive.

William Rice, president and CEO of Vivilon Coatings Inc. in Miami, Fla., a manufacturer of surface-restoration and protection coatings, advises implementing a bimonthly inspection program for signs of early paint aging, and correcting those areas by proper reapplication of the appropriate coating. Coating and sealant touch-ups are simple and can be done by in-house staff, though a paint contractor can be retained to do the work.

“Dirt is one of the most overlooked enemies of paint,” Rice says. “It can’t be overemphasized that a monthly surface washing can easily double the life expectancy of almost any quality product. Brushing with a good neutral-pH cleaner and rinse would be preferable; but even a quick hose down would greatly increase the durability of any paint. Nothing can be done about UV radiation, or extremes of hot or cold; but cleaning off surface grime is quick, easy and inexpensive,” he says.

“In addition to regular maintenance inspections in the spring and fall, it would be in the owner’s best interest to inspect roofs after storms or heavy winds to make sure there is no weather-related damage,” advises Kessler.

“Heavy snow loads and ice removal can cause damage such as gouged or split panels, loose fasteners, split seams, etc.,” warns Rick Thomas, marketing manager for Binghamton, N.Y.-based, Insulating Coatings Corp., a manufacturer of roof-coating systems for metal roofs. “If rust or corrosion is present, a rust primer should be applied prior to the waterproofing and after the roof is completely power-washed,” he says.

Floor Coatings

Storage owners may ask, “Why should I seal my concrete floors?” Concrete is a porous and unique building material. “In its unsealed state, concrete absorbs moisture and liquid spills as well as collects dust in its pores, which reside below the surface,” says Don Crawford, president of Chemisol Resources Group Inc. in Glendale, Ariz. The company specializes in sealing and maintenance of concrete surfaces and manufactures a water-based acrylic sealant.

“As the self-storage industry has evolved, it has increased its level of services and sophistication. Customers are attracted to clean, bright, well-maintained facilities,” Crawford says. “A clean floor reduces dust and helps maintain this image. Sweeping and mopping helps, but is extremely difficult to do on an unsealed concrete floor because of the drag created by the surface texture.”

A quality sealant may average three to six months between applications, depending on wear and level of floor maintenance, Crawford says. Wear is determined by a number of factors, such as facility traffic, performance of intermittent sweeping and damp mopping, and destructive use, such as scratches and scrapes. Crawford recommends using a regular cleaning service, with the frequency determined by the type of flooring, facility traffic and desired level of appearance. Owners should use a service that specializes in the sealing and maintenance of concrete surfaces. Between services, owners can use a pH-neutral cleaner for daily maintenance.

Protecting Doors and Buildings

Teresa Sedmak, president of Everbrite Inc., a Reno, Nev.-based manufacturer of a protective coating that refinishes faded and dull metal buildings, advises owners to check metal surfaces for fading, oxidation and corrosion at least once a year. “An easy way to check the degree of fading and loss of gloss is to observe an area that is wet,” she says. “Use a wet finger, cloth or sponge to touch the area. If there is a noticeable difference in color or gloss, the metal should be sealed and protected before it gets worse.” Once fading begins, deterioration will accelerate rapidly and become more labor-intensive and expensive to fix.

“Check for salt corrosion by running your hand over the top ribs of a roll-up door on the north or east side of the facility, where the moist salt air sits for a longer time before it dries,” Sedmak says. If there is corrosion, the surface will be rough or bumpy. In this instance, application of a coating will fix the problem. On the other hand, acidrain damage can only be prevented by sealing the metal. Once acid rain etches a surface, there is nothing that can be done to refinish it.

Application. To refinish and protect a metal surface, first remove all chalk, grime, alkaline salts or any other contaminants. “Purchase a coating that can be sprayed or wiped on and can be repaired if a mistake is made,” Sedmak says. “If care is taken to follow all directions, properly prepare the surface and apply the coating, self-application can have good results.” She does, however, suggest using a professional applicator, as it will be experienced with storage facilities, and know how to keep water out of the units and solve the variety of cleaning and application challenges roll-up doors can present.

A gallon of quality clear coating should cover about 20 to 24 large roll-up doors (roughly 1,200 square feet). Owners considering repainting vs. coating surfaces should consider cost on a per-square-foot basis, says Sedmak. While a gallon of paint is less expensive than a quality clear coating, the cost per square foot may be much higher because of coverage. Paint will also start to fade in a year, but a clear coat should not fade for many years. A good cost for materials is about 15 to 20 cents per square foot, Sedmak says.

Upkeep. A clear-coat finish can be renewed every five to 10 years. “Make sure the coating is self-annealing and will self-blend so the first coat does not need to be stripped off,” Sedmak says. Also look for a coating that will expand and contract with the metal so it will not crack and peel. Avoid thick or very hard coatings like lacquer or paint, which are not flexible. Once buildings are sealed and protected, they can be simply washed with water. In the case of more difficult stains, a mild, neutral-pH soap solution can be used.

Final Words

“Most industries underestimate the importance of sealants in the lifetime performance of their structures,” Hensley says. While it is possible to ensure long-term waterproofing for as little as .5 percent of the average cost of a building, owners and builders tend to consider sealants an accessory to be purchased for the lowest possible cost. “Consequently, the best cure is an ounce of prevention. In other words, the costs of remediation of failed sealants will significantly outweigh the costs of using a high-performance sealant up front,” he concludes.

Last year, China used 55 percent of the world’s cement and 36 percent of its steel, according to an April article in The Independent, a U.K. newspaper. This consumption has resulted in skyrocketing prices for steel materials, including self-storage building components. Now more than ever, maintenance of your metal structures makes more economic sense than replacing them.

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