Marine Lumber Makes Inroads In Green Construction

When it comes to a wet environment, marine lumber offers a durable, environmentally safe alternative to traditional wood.

The green building industry is growing steadily as more consumers, municipalities and builders recognize the broad benefits that it provides. For consumers, what resonates most about green building is its contribution to clear air and water, and reduced exposure to toxins, according to a U.S. Green Building Council research study. 

From advancing the efficient use of energy, water, and other resources, to reducing indoor pollution and toxins released into the air, ground, and waters, green building’s charismatic benefits have led to marine lumber’s great popularity. The industry has grown to an $81 billion market in the United States alone, according to Statista research. Adding to its strong value proposition are the day-to-day and year-over-year cost savings that green building projects deliver to homeowners and contractors. 

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Marine lumber is certified by the Forest Service Council to have been responsibly harvested. It can lead a trend away from concrete and steel in sustainable building construction. Credit: George Stanley/Flickr

For waterfront properties, in particular, one material that is providing significant benefits from an environmental and cost standpoint is sustainable marine lumber. Builders constructing properties in waterfront settings should consider this material, which marine contractors working in sectors ranging from oceanfront communities to bridges, marinas, ports and harbors are increasingly opting for.

Regulatory Drivers

Key to the growing popularity of sustainable marine lumbers has been legislation designed to protect our waters and surrounding environments. Chief among these laws are the National Environmental Policy Act of 1969 and Clean Water Act of 1972. In addition, a series of very high-profile maritime incidents involving major oil spills helped step up regulations and enforcement actions by agencies such as the U.S. Environmental Protection Agency (EPA), National Oceanic and Atmospheric Administration (NOAA), and U.S. Department of Commerce. 

While laws were passed to govern the transport of hazardous materials, many also emphasized construction materials that do not leach hazardous chemicals into the water or are prone to degrade in less than 10 years. Materials that have been traditionally specified are reinforced concrete, coated steel and composite plastics. 

Sustainable marine lumbers are newer to the field but are quickly gaining ground for their environmentally sound properties and other attributes. In addition, nothing can compare to the look and feel of natural wood. Not only does sustainable wood protect the environment where it is installed, but it also protects the forest where the wood originates. It gives the forest a value, which protects it from destruction by miners or plantation farmers. Advances in sustainable marine lumber

It began back in the Industrial Revolution, when economic development activities were first identified as having a negative impact on the environment. Fast forward to more recent years, and several key regulatory initiatives and guidance appear: 

  • The Coastal Zone Act Reauthorization Amendments of 1990, which began regulating marinas’ activities relating to their addition of pollutants in coastal waters.
  • Enhancements to the Clean Water Act, including the National Pollutant Discharge Elimination System, which provided direction on marina design and construction through the EPA’s and NOAA’s joint effort, the Coastal Nonpoint Pollution Control Program. 
  • More widely applied guidance from research that provided builders of diverse projects, from commercial to residential, a best practices process for sustainable development and project management. 

Ethical sourcing of sustainable marine lumber is a mandate of the Forest Stewardship Council. Under its FSCC117772, select marine lumbers are certified to have been harvested from forests that are managed responsibly according to environmental, social and economic goals. These lumbers also reflect the principles of eco-friendly construction and engineering with nature principles. 

Among the prominent sustainable marine lumbers is greenheart wood, which is responsibly harvested from Guyana. Greenheart (a.k.a. Chlorocardium Rodiei) is highly valued for its high strength and durability, as well as its pest and marine borer resistance. This sustainable marine lumber is virtually immune to rot and requires minimal maintenance. 

Marine Saltaire_Boardwalk_1 featured

A high-density wood, environmentally friendly marine lumber glues easily, holds nails well and almost never requires staining. Credit: Courtesy of Evergreen Forest Products

This latter factor is key in eliminating the risk of toxic chemicals spilling into water. In contrast, soft woods such as pine not only rot and give way to insects, but they are also subject to heavy mold and fungi, therefore requiring regular maintenance and the related costs. These soft woods, along with composites, have lifespans of approximately 25 years, which is one-third that of sustainable marine lumbers such as greenheart, with a lifespan of more than 75 years.

Sustainable Marine Lumber Applications

Hard-wearing properties of greenheart can have a blunting effect when sawing or machining, therefore power is required, and the saw blade or machine may need changing on a fairly high frequency.

Builders will appreciate the sustainable marine hardwood’s turning and planing properties, despite its high density with interlocking grain lumber. Other perks for its application include its ability to glue easily and hold nails well within the recommended pre-boring for nails and screws. It requires little, if any, staining and polishes well. 

Aesthetically, it is attractive lumber for residential and municipal waterfront properties. It offers a fine to medium-fine grain, which varies from straight to interlocking and has an appealing natural luster. Typically, heartwood has a pale olive green shade, often with a darker streaking accent. Its sapwood is yellowish green. 

This sustainable marine lumber is well-suited for use in docks, decks, handrails, boardwalks and flooring, as well as in piers, lock gates, ferry stations, and harbor works.

Other key properties of sustainable marine lumber further illustrate the product’s performance features, and construction and application benefits:

  • Air dried density (12%) of 970 kg/m3 (kilogram/cubic meter)
  • Bending strength (at 12%) of 240 N/mm²
  • Modulus of elasticity (at 12%) of 24500 N/mm²
  • Class A Fire Rating, making it highly resistant to fire, and it does not spread flames quickly.

Protecting Marine Life Ecosystems

For those concerned with the impact of construction on the environment, sustainable marine lumber has a minimal negative effect on waterways, wetlands and marine ecosystems. That’s a big point, because of the myriad of ecosystems that exist. On the East Coast, for example, striped bass, fluke, blackfish, crabs and lobsters, along with organisms such as corals, sponges, tunicates and sea anemones, reside in marine ecosystems. 

Gulf stream waters and their environs are home to groupers, angelfish, triggerfish and butterfly fish. The Gulf Coast of Florida provides a natural habitat for many sea turtles, dolphins and manatees. Sustainable marine lumber does not introduce any pollutants into marine environments. 

Among the prevailing trends in green building today is the use of new building tools designed to calculate a property’s carbon footprint from its inception to its completion. This tool evolved from the application of building information modeling wherein computer-generated images enable contractors to envision their projects and how different construction materials will perform over time. 

Using a carbon footprint calculator, a builder can determine the amount of energy used to produce the building materials, and what the carbon footprint of different building materials will be. The builder can determine, thereby, which would be the optimum choice from a standpoint of sustainability and environmental protection. 

Given their properties and lifespans, sustainable marine lumbers are likely to perform well under the carbon footprint calculation test. These lumbers also support the trend away from concrete and steel and towards wood for its properties in reducing greenhouse gas emissions.