Clear exterior finishes: finding the balance between aesthetics and durability

JCT CoatingsTech, Sept, 2004 by Tom Daniel, Marc S. Hirsch, Ken McClelland, Alan S. Ross, R. Sam Williams

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WHY WOOD ANYWAY?

Wood is the material of choice for a wide range of building projects. It offers the builder a long list of features that work together to meet the end user's expectations for service, cost, and appearance.

Perhaps the greatest attribute of wood is its versatility. Wood can be used indoors and outdoors in both structural and appearance applications. Whether the needs are clear or knotty appearance, rough or smooth texture, wood can meet the changes in design and fashion. It can be specified from the hundreds of standard sizes and patterns or custom ordered to meet particular needs. Wood products are widely distributed and readily available throughout the United States and Canada.

Another factor favoring the use of wood is its ease of handling and fabrication. Wood can be shaped, drilled, cut, and fastened with common tools that can be operated by homeowners and professional contractors alike.

Buildings constructed from wood have a history of excellent service. Interior beams, ceilings, paneling, and trim will last the lifetime of the building. Wood products are widely used for exterior siding, trim, decks, and landscape projects. Species such as redwood and cedar contain natural preservatives that make them particularly well suited to exterior environments.

Using wood rather than other materials is environmentally friendly. The production of wood products generally requires much less energy than producing alternative products, which lowers both fuel consumption and air emissions. And, wood is the only renewable building material. The nation's move toward sustainable forestry practices (for example, the planting of more than two billion trees each year in North America) assures a continued supply of wood for generations into the future.

The beauty of wood has long been admired. The warm colors and rich grain patterns have decorated homes and their landscapes for centuries. This natural beauty can be enhanced and preserved through the proper selection, application, and maintenance of a finish.

SUMMARY

Matching the aesthetic desires of homeowners with the protective requirements of wood using technologies available today is a delicate balancing act. By having an understanding of the benefits and limitations of the various natural clear finishes, the homeowner's expectations for performance and maintenance can be satisfied. Determining which product to use can be difficult. Product quality is often defined by the reputation of the manufacturer, the ingredients used (in sufficient quantities to be effective), and the delicate blending and balancing of the various raw materials used in the coatings formula. High quality, clear wood finishes should be easy to use, contain mildew-preventing ingredients, provide some degree of water repellency, and contain UV radiation absorbers. Generally, clear finishes fully exposed to the weather last one to two years; however, some last less than a year. Research is needed to achieve a quantum leap in the technology of clear finishes for wood.