Code considerations and installation
In addition to environmental attributes, performance and appearance, code approval is an important factor to consider when selecting decking products. To be approved under the International Residential Code (IRC) and International Building Code (IBC), for example, a composite decking product must have an International Code Council (ICC) Evaluation Service (ICC-ES) report, confirming it has passed a series of tests outlined in the ICC-ES document AC174, Acceptance Criteria for Deck Board Span Ratings and Guardrail Systems (Guards and Handrails) (June 1, 2009).
The tests evaluate a product’s structural properties, durability and surface-burning characteristics, including span, fastener holding ability, elasticity, bending strength, ultraviolet (UV) and freeze-thaw resistance, fire performance, termite resistance and the effects of temperature, moisture and fungal decay. To find out if a product is code-approved, check the manufacturer’s website or the ICC-ES website (www.icc-es.org). If approved, the product packaging should include its code listing.
Understanding building code regulations and substructure requirements for spans is essential with composite decking. Typically, composite deck boards require a 406-mm (16-in.) on-centre joist span for installation and 305-mm (12-in.) span for diagonal installation. Composite decking follows underlying support surfaces more closely than wood planks do, so it is important to ensure joists are level with one another to avoid a wavy surface appearance.
Like solid lumber, composite decking materials are easily machined, and can be installed with standard hand and power tools. Since composite boards have no grain, there is no risk of splitting. To attach composite boards to underlying structural members, builders can use nails, screws or hidden fastening systems. For some composite decking products, stainless-steel trim head screws can minimize the chance for metal corrosion or staining on the material. However, not all composite decking products are compatible with each attachment method, so it is important to follow manufacturer recommendations.
Engineered, long-lasting beauty
Composite decking and railing offers an engineered option for builders and landscape professionals seeking a durable, environmentally sound alternative to conventional building materials. And, with a little research to ensure the material chosen meets the performance and design goals for a project, it can offer enduring strength and beauty for many years.
| ECO-FRIENDLY CARE AND CLEANING |
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| All decking requires maintenance for long-lasting beauty and durability; composite products are no exception. Manufacturers typically recommend periodic cleaning—sweeping to remove dirt and debris, and if necessary, a soft bristle scrub brush with mild soap and warm water to gently remove spots. Pressure washers can also be used to clean composite decking. Maximum pressure amounts can differ depending on the manufacturer. To avoid damage to the deck boards, a pressure washer typically should be set at less than 90 kgf/cm2 (1,280 psi) and have a fan tip blade that is held at least 203 to 254 mm (8 to 10 in.) away from the surface. For tannin stains (e.g. from plants, coffee, tea and wine) or stubborn spots, cleaners containing oxalic acid (C2O4H2), commonly known as deck ‘brighteners,’ can be used to remove them. In some cases, difficult-to-remove stains or spots may require multiple applications. Cleaners should always be tested in an inconspicuous area of the deck before full application, to ensure the desired results. Most conventional composite deck cleaners contain sodium hypochlorite (NaOCl), which can help prevent and fight mould and mildew. Any cleaner containing bleach may lighten the decking surface and should be used in accordance with the manufacturer’s instructions. Plants and shrubs around a deck should be sprayed with water before and after the use of cleaning solutions. Oxygen-based bleach cleaners, often referred to as oxygenated bleach, provide an environmentally conscious alternative to chlorine-based bleach. Cleaning alternatives that do not contain bleach, ammonia (NH3) or volatile organic compounds (VOCs) are also available. |
Brent Gwatney is vice-president of sales and marketing for MoistureShield, a composite decking materials manufacturer in Springdale, Ark. He can be reached at bgwatney@aert.cc.
