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Alternative Construction Materials Enhance Aesthetics and Reduce Environmental Impact

August, 2004

Everyone has heard the adage about building a better mousetrap, but how about a better, longer lasting and more attractive dock? A new company headquartered in Virginia Beach is using PVC to make pilings, boat lifts and other pier accessories to replace treated wood as the preferred building material.
ArmorDock Systems, Inc., a collaboration between engineers and investors, has developed a PVC pile that is UV stable and impact modified for prolonged exposure in the marine environment. The piles provide support for composite or traditional timber deck structures. PVC is a superior material for continuous water contact because its anticipated service life is 50 years compared to timber’s 15 years, not to mention the environmental damage caused by treated timber as chemicals leach into the water.
The Environmental Protection Agency (EPA) has already taken action on CCA (Chromated Copper Arsenate), the most popular preservative treatment for timber. In February 2002, the EPA announced requests to cancel certain CCA products. The requests proposed that only certain uses of CCA be allowed as of December 31, 2003. The requests were made as a result of current and projected market demand for CCA products and the availability of new generation wood treatment products. The EPA considered these voluntary moves toward arsenic-free wood treatment products as a positive step, believing that reducing the potential residential exposure to a known human carcinogen was desirable. The transition affects all future residential uses of wood treated with CCA, including that used in playground structures, decks, picnic tables, landscaping timbers, residential fencing, patios, walkways and boardwalks.
Effective December 31, 2003, this product may only be used for preservative treatment in accordance with specific uses cited in the 2001 edition of the American Wood-Preservers Association Standards. One of these approved uses is Lumber and Timber for Salt Water Use Only (C2), however, several states have enacted regulatory measures which strictly prohibit CCA treated timber in the marine environment.
pvc pier accessories
Company literature indicates that ArmorDock Systems expects the EPA ban on CCA-treated timber to include marine uses in the near future, and as a consequence, they are uniquely positioned to provide a better alternative. The firm has four patents in its name and two are in the patent approval process. Patents cover the boatlift, a seawall, sleeving existing piles, and a pile hammer-water jet, but the heart and soul of ArmorDock is the PVC pile.
Inventor, engineer and investor, Pete Mansfield of Urbanna, VA, developed the PVC compound and pile design in conjunction with Hawk Plastics of Alpine, AL. The resulting pile size, shape and color provide a most pleasing departure from the irregular nature of timber piles. The SDR35 pile is manufactured in Alabama and distributed through a nationwide network of wholesalers and contractors.
To develop bearing capacity, the pile is installed with an open end thereby creating twice the skin friction as a traditional pile. Point bearing is accomplished by installation with a closed end or by flushing bottom sediments out of the pile after installation and filling the pile with concrete, sand, crusher run, etc.
Piles are installed with a patented hammer/water jet that weighs only 60 pounds. The pneumatic system operates automatically at an adjustable speed to drive the pile into the bottom sediment. The hammer includes a fitting for a water line to convert the hammer into a water jet. Piles can be installed by impact, or water jet, or a combination of both methods to best suit site conditions and contractor equipment.
Old, deteriorated timber piles can be rehabilitated in place with ArmorDock piles according to the company. The existing pile is disconnected from the pier while the pier is temporarily supported. An ArmorDock pile is installed over the existing timber pile, and the spaces between the PVC pile and timber pile are filled with concrete, sand or other material. The rejuvenated pile is then reattached to the existing pier. This sleeving operation is simple, inexpensive and quick, and the owner extends the pier service life by 50 years or more.
According to the company, the distinct advantage of ArmorDock piles is most apparent in their line of boatlifts. The motor and gearbox assembly is completely contained within the pile, leaving only the boat cradle, wire rope and drive pipe exposed to the elements. By using a non-conductive drive shaft between the motor and gearbox, safety from electrical shock is assured.
Looking to the near future, ArmorDock is developing a composite and modular dock system to further reduce the labor expense associated with dock construction. Half the cost of existing docks is in labor, so once the contractor is finished, the dock represents only half the investment company officials note. By increasing material cost while not increasing overall cost, the dock will represent the majority of the owner’s investment.
Of the eight company owners, six are engineers. In addition to Pete Mansfield, the engineering staff at ArmorDock includes Tom Langley, Gary Bowers, Joe Harvey, Dennis Clark, and Larry Moody.

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