The Perfect Dock Plank for Extreme Marine Environments


A center for retail and industry, South Portland, Maine is known for its majestic harbor overlooking the city’s skyscape and nearby Casco Bay islands.

Along this waterfront is also Breakwater Marina, a 121-slip dockominium managed by Port Harbor Marine, Maine’s largest boat dealer. Breakwater Marina has spent millions of dollars to build and upgrade the marina and surrounding properties due to the constant assault of salt water and extreme weather conditions. In fact, the area’s cold, snowy winters and warm summers are often punctuated by severe nor'easters and wind gusts topping 50 mph to consistently reap havoc on the floating dock’s structure.

As a result, Custom Float Services of South Portland spent the past four seasons systematically replacing nearly 15,000 sq. ft. of Douglas fir decking, which had deteriorated since its original installation 22 years ago.

“This is an extremely tough climate for docks,” says Scott Dyer, the company’s general manager. “Nor'easters are frequent year-round. Even pressure-treated decking disintegrates in slow fashion due to the high acidity. Plus, the maintenance is costly and ongoing, often requiring annual inspection and repair or replacement of dock planks that have failed over time.

 “Subsequently, we decided the next phase of the marina would only include low-maintenance, composite dock boards. Our goal was to create an infrastructure and surface that looked great for decades without the time and costs associated with continually refurbishing the boards.”  

Having worked in the industry for 25 years and thoroughly understanding the value of strength, mass and thickness in such applications, Dyer chose DuraLife™ Dock & Boardwalk planks made for heavy-duty use in commercial and residential marine applications. Per Dyer, these boards are not only 1.125" making them “1/8th of an inch thicker than most composite boards,” but also “far sturdier” due to their polypropylene design. When compared to competitive dock plank products made with polyethylene, polypropylene has been tested to show greater resistance to heat, chemicals, and staining while remaining structurally sound and durable. 

“We used the DuraLife planks in numerous projects over the past 10 years and there were never any complaints even in intense environments,” offers Dyer. “We thought it was the ideal choice for meeting both our design criteria and budget for the Breakwater Marina. In addition, we had worked with various other deck boards over the years and just found them flimsy.

“The DuraLife boards don’t bend or flex. Since they are stronger and wear better, you can actually set them 24” off center compared to similar decking, which have to be placed 12” to 16” off center. This benefit alone greatly reduces cost by requiring less support and framing.”

During the four-phase installation process, more than (amount) coastal grey DuraLife deck boards were placed on a timber frame combining pressure-treated southern yellow pine and Weyerhaeuser Parallam® PSL Beams. The planks were then secured with 3.16 grade stainless steel screws to ensure long-term durability against the elements.

Other benefits supplied by the DuraLife planks include a multi-layered finishing system that resists fading over time, a deeply-embossed wood grain that provides excellent traction, even when wet and low-maintenance design that resists rotting, wearing, staining, and warping. It also never needs painting or staining.

“We’ve spent 25 years perfecting a process specific to customer needs,” adds Dyer. “We do not sell production-type decks. Everything we do closely considers site conditions, usage and all other forms of user characteristics. The proper choice of materials is integral to long-term customer satisfaction. That is why we use nothing but the best for each job.”