Sustainable composite decking offers a compelling alternative to traditional wood, balancing aesthetic appeal with environmental responsibility. This guide delves into the multifaceted world of sustainable composite decking, exploring its materials, manufacturing processes, performance, design considerations, and overall sustainability.
From the initial choice of materials to the long-term maintenance, this in-depth analysis will equip you with the knowledge needed to make informed decisions about your decking project. We will discuss the various types of composite decking available, highlighting their unique features and benefits.
Introduction to Sustainable Composite Decking
Sustainable composite decking materials are engineered products combining wood fibers or fillers with plastic resins, often incorporating recycled content. These alternatives to traditional wood offer a range of environmental and practical advantages, particularly in reducing the environmental impact associated with harvesting and processing timber.The use of composite decking mitigates deforestation concerns, reduces reliance on finite wood resources, and lowers the carbon footprint compared to conventional wood decking.
This reduced environmental impact is a key driver in the growing popularity of sustainable composite decking.
Definition of Sustainable Composite Decking
Sustainable composite decking encompasses a range of engineered materials designed to mimic the look and feel of natural wood while minimizing environmental harm. These products are typically composed of recycled materials, such as plastic and wood fibers, combined with resins and additives. This blend of materials results in a durable and weather-resistant alternative to traditional wood decking, while also reducing the reliance on virgin wood resources.
Environmental Benefits of Composite Decking
Composite decking significantly reduces the environmental impact compared to traditional wood decking. The production of composite decking often involves the use of recycled materials, reducing the demand for virgin wood and associated deforestation. Lower water usage in manufacturing and reduced chemical treatment requirements further contribute to the environmental benefits. Additionally, the long lifespan of composite decking reduces the need for frequent replacement, minimizing waste generation over the product’s life cycle.
Types of Sustainable Composite Decking
Various types of sustainable composite decking are available, each with unique characteristics and benefits. These include products featuring wood fibers, plastic resins, and recycled content. Different blends of these materials affect the aesthetic, durability, and performance characteristics of the decking.
Composite Decking Brands and Sustainability Claims
Numerous brands offer sustainable composite decking options. For example, CertainTeed offers composite decking with recycled content, highlighting its commitment to environmental responsibility. Other brands, such as Trex, promote the use of recycled materials and sustainable forestry practices in their product development. Specific claims regarding recycled content, reduced carbon footprint, or specific environmental certifications should be verified through product documentation.
Comparison of Composite Decking Materials
| Material | Durability | Maintenance | Cost |
|---|---|---|---|
| Wood-Polymer Composite (WPC) | Generally high, resistant to rot and insect damage | Low, minimal cleaning required | Moderate to high, depending on the specific brand and quality |
| Plastic Composite | High, resistant to rot, insect damage, and weather | Low, minimal cleaning required | High, typically higher than wood-polymer composite |
| Recycled Content Composite | High, comparable to other composite types | Low, minimal cleaning required | Moderate to high, varying with the percentage of recycled material |
| Bamboo Composite | High, resistant to rot and insect damage | Low, minimal cleaning required | Moderate to high, depending on the bamboo source and manufacturing process |
This table provides a general comparison of composite decking materials based on key factors. Individual product variations can influence these characteristics. Consult product specifications for detailed information.
Manufacturing Processes and Materials
Sustainable composite decking offers a compelling alternative to traditional wood decking, leveraging innovative manufacturing processes and a diverse range of materials. These processes and materials are carefully chosen to minimize environmental impact throughout the lifecycle of the product, from sourcing raw materials to final disposal. The selection of materials and manufacturing methods directly influences the sustainability credentials of the composite decking.The manufacturing process for sustainable composite decking typically involves a combination of mechanical and chemical processes.
Careful consideration is given to the types and quantities of materials used, as well as the energy consumption and waste generation associated with each step. This holistic approach to production aims to minimize the overall environmental footprint of the decking.
Manufacturing Processes
The manufacturing process of sustainable composite decking generally involves several key steps. These steps typically include material preparation, mixing, molding, and finishing. Material preparation involves shredding, grinding, and drying of the recycled and renewable materials, ensuring a consistent quality and homogenous mixture. The mixing process combines these prepared materials with resin and other additives, creating a homogeneous composite.
This composite is then molded into the desired shapes and dimensions, often using specialized machinery. Finally, the molded decking undergoes a finishing process, such as sanding and staining, to achieve the desired aesthetic and durability.
Materials Used
Sustainable composite decking frequently incorporates a blend of recycled and renewable materials. This approach helps reduce reliance on virgin resources and minimizes waste generation. Common materials include recycled plastics, wood fibers (often from sustainably managed forests), and agricultural byproducts.
Sourcing of Raw Materials and Sustainability Impact
The sourcing of raw materials plays a crucial role in the overall sustainability of composite decking. Prioritizing recycled content, such as plastic bottles or agricultural waste, reduces the demand for virgin resources. Furthermore, the use of sustainably sourced wood fibers ensures responsible forest management practices. The specific sourcing of materials can significantly influence the environmental impact of the entire production process.
For example, using recycled plastics from post-consumer sources, rather than industrial waste, can reduce the carbon footprint.
Environmental Impact of Manufacturing Processes
Each manufacturing process has an associated environmental impact. Energy consumption, water usage, and waste generation are key factors. Manufacturing processes employing advanced technologies to reduce energy consumption and optimize material use are essential to achieve a truly sustainable product. For instance, employing efficient drying techniques in the material preparation stage can significantly reduce energy usage.
Comparison of Composite Decking Materials
| Material | Sourcing | Processing | Environmental Impact |
|---|---|---|---|
| Recycled Plastic | Post-consumer plastics, such as bottles and packaging | Shredding, cleaning, and blending with other materials | Reduced reliance on virgin materials, lower energy consumption in some cases compared to virgin plastic production |
| Recycled Wood Fibers | Sustainable forestry practices, with emphasis on responsibly managed forests and post-consumer wood waste | Grinding, cleaning, and blending | Reduces pressure on natural forests, lower carbon footprint than virgin wood |
| Agricultural Byproducts | Agricultural residues (e.g., corn stalks, rice husks) | Processing into fibers, blending with other materials | Reduces waste generation from agriculture, provides a renewable alternative |
| Virgin Wood Fibers | Certified sustainable forests, with emphasis on reforestation | Grinding, cleaning, and blending | High carbon footprint if not from certified sustainable forests |
Performance and Durability
Sustainable composite decking offers a compelling alternative to traditional wood, boasting impressive durability and longevity. Its inherent resistance to weather, coupled with minimal maintenance requirements, makes it an attractive choice for homeowners seeking a low-maintenance, long-lasting outdoor space. This section will delve into the performance characteristics of various composite decking materials, examining their resistance to environmental factors, impact resistance, and overall lifespan.Composite decking’s exceptional durability stems from its composite nature, blending wood fibers or other natural materials with plastic resins.
This combination creates a product that is inherently more resistant to the damaging effects of moisture, rot, and pest infestation than traditional wood decking. The material’s resistance to environmental degradation is a key factor in its longevity.
Durability and Longevity
The longevity of sustainable composite decking varies depending on the specific material composition and manufacturing process. While precise lifespan estimates are challenging to quantify, many composite decking products demonstrate a substantial lifespan exceeding 20 years, often surpassing the lifespan of comparable wood decking. The long-term performance of composite decking hinges on its ability to withstand various environmental stressors.
Resistance to Weather Elements
Composite decking materials exhibit varying degrees of resistance to weather elements. The primary elements affecting outdoor decking include sun exposure, rain, snow, and temperature fluctuations. Generally, high-quality composite decking materials are formulated to resist the damaging effects of UV radiation, maintaining their color and aesthetic appeal for extended periods. However, the specific resistance levels can differ between composite decking types.
Impact of UV Exposure and Fading
Ultraviolet (UV) radiation from sunlight is a significant factor in the degradation of outdoor materials. Composite decking materials are designed with UV stabilizers to mitigate the effects of fading and discoloration. The effectiveness of these stabilizers differs between manufacturers and product types. While some composite decking materials exhibit minimal fading over time, others may show subtle color changes after prolonged exposure.
Thorough research into the UV stabilization properties of different brands and types is crucial when making a purchase decision.
Maintenance Requirements
Composite decking requires significantly less maintenance than traditional wood decking. Regular cleaning with soap and water is usually sufficient to maintain its aesthetic appeal and functionality. The absence of need for staining, sealing, or repainting saves considerable time and effort compared to wood decking, making it a highly desirable low-maintenance option.
Comparison of Impact Resistance
Different composite decking materials exhibit varying levels of impact resistance. The density and resin content play a significant role in the material’s ability to withstand impacts. Factors such as foot traffic, furniture placement, and potential accidental impacts should be considered when selecting a composite decking material. Manufacturers often provide data regarding impact resistance, allowing consumers to compare different products based on their performance characteristics.
Comparison Table: Composite Decking Types
| Decking Type | UV Resistance | Impact Resistance | Maintenance | Typical Lifespan |
|---|---|---|---|---|
| High-Density Polyethylene (HDPE) | Excellent | Good | Low | 20+ years |
| Polyvinyl Chloride (PVC) | Good | Moderate | Low | 15-25 years |
| Wood-Polymer Composites (WPC) | Good | Good | Low | 20+ years |
Design Considerations and Applications
Sustainable composite decking offers a wide range of design possibilities, catering to diverse architectural styles and climatic conditions. Its durability and low maintenance requirements make it a practical choice for homeowners seeking long-lasting outdoor living spaces. This section explores various deck layouts, installation techniques, and design examples, highlighting the versatility of this material.
Deck Layout Design Considerations
Careful consideration of the site’s specific conditions, architectural style, and desired functionality is crucial when designing a deck. Factors such as sun exposure, prevailing winds, and the surrounding landscape significantly influence the deck’s layout. A deck’s orientation, for example, can maximize sun exposure in warmer climates or provide shade in hotter regions. Similarly, the deck’s proximity to trees or other structures needs careful consideration to avoid potential shade or wind issues.
Installation Techniques for Sustainable Composite Decking
Proper installation is paramount to the longevity and performance of composite decking. A well-installed deck ensures structural integrity, water drainage, and prevents premature deterioration. Careful adherence to manufacturer guidelines is essential for achieving a high-quality installation. Key aspects of the installation process include proper sub-structure preparation, securing the joists, and precise fastening of the decking boards.
Deck Design Examples Incorporating Composite Decking
Numerous deck designs are possible with composite decking. A contemporary deck could feature a clean, minimalist aesthetic with straight lines and simple railing designs. A more traditional design might incorporate columns and intricate balustrades. In warmer climates, a multi-level deck with shaded areas and outdoor living spaces could be incorporated. The design options are limited only by the homeowner’s imagination and the specific needs of the site.
Fastening Methods for Composite Decking
Various fastening methods are available for composite decking, each with its own advantages and disadvantages. The appropriate method depends on the specific deck design, the type of composite material, and the desired level of aesthetic appeal. Common fastening methods include screws, nails, and specialized composite decking clips. The choice between methods also considers the environmental impact and the longevity of the fastening mechanism.
Comparison of Installation Techniques
| Installation Technique | Materials Needed | Estimated Time (per sq ft) | Notes |
|---|---|---|---|
| Standard Screw Fastening | Composite decking boards, screws, drill, wood screws, pre-drilled holes, joists, underlayment, sealant | 0.5-1 hour | Common, reliable method, ensures strong attachment. Requires precise pre-drilling for optimal results. |
| Decking Clips | Composite decking boards, decking clips, drill, wood screws, joists, underlayment | 0.75-1.5 hours | Faster installation than screw fastening, requires specialized clips. May offer enhanced aesthetic appeal, but cost may be higher. |
| Nail Fastening (less common for composite) | Composite decking boards, nails, hammer, joists, underlayment | 0.75-1.25 hours | Traditional method, less common for composite due to potential damage to the material. |
Note: Estimated times are approximate and can vary based on the complexity of the deck design and the installer’s experience.
Environmental Impact and Sustainability Certifications
Sustainable composite decking offers a compelling alternative to traditional wood decking, but its environmental impact and sustainability certifications are critical considerations. Choosing a composite decking material with a strong commitment to environmental responsibility ensures a product that aligns with long-term sustainability goals. Careful selection of materials and manufacturing processes, along with adherence to recognized standards, are vital for minimizing the environmental footprint throughout the product’s life cycle.
Environmental Footprint of Sustainable Composite Decking
The environmental impact of composite decking varies depending on the specific materials used in its manufacture. Products made from recycled materials, or using renewable resources in their production, generally have a lower environmental footprint. Factors such as the sourcing of raw materials, energy consumption during manufacturing, and end-of-life management all contribute to the overall environmental impact.
Life Cycle Assessment of Composite Decking Materials
A life cycle assessment (LCA) evaluates the environmental impact of a product from its raw material extraction to its eventual disposal. LCA studies for composite decking materials analyze the environmental effects associated with each stage of the product’s life, including material sourcing, manufacturing processes, transportation, installation, and eventual disposal. Different composite decking materials exhibit varying LCA results depending on their component composition and the specific manufacturing processes employed.
Comparative LCAs are crucial for informing consumers about the environmental performance of various composite decking options.
Sustainability Certifications and Standards
Recognized certifications and standards play a vital role in verifying the sustainability claims of composite decking products. These certifications typically assess the environmental impact of the product throughout its life cycle, including material sourcing, manufacturing processes, and end-of-life management. The certifications provide assurance to consumers about the sustainability practices employed by the manufacturers. Some well-regarded certifications for sustainable composite decking include the Forest Stewardship Council (FSC) certification and Greenguard certification.
Certifications for Composite Decking Brands
Various composite decking brands utilize different sustainability certifications to demonstrate their commitment to environmental responsibility. This variety reflects the evolving standards and expectations in the market. Consumers can find certifications and standards specific to each brand by reviewing their product information and manufacturer websites.
Summary Table of Certifications
| Certification | Criteria | Associated Benefits | Examples of Brands Using Certification |
|---|---|---|---|
| Forest Stewardship Council (FSC) | Ensures responsible forest management practices, promotes biodiversity, and supports local communities. Focuses on the responsible sourcing of wood fibers, or other certified renewable materials. | Demonstrates commitment to sustainable forestry, reducing deforestation, and promoting ecological balance. | Many brands featuring wood fiber composites in their products. |
| Greenguard Certification | Evaluates the release of volatile organic compounds (VOCs) into the indoor air. Products with low VOC emissions are favored. | Ensures healthier indoor environments by minimizing potential health risks associated with exposure to harmful chemicals. | Brands prioritizing low-VOC composite materials. |
| Sustainable Forestry Initiative (SFI) | Focuses on sustainable forestry practices. Standards encompass forest management, biodiversity conservation, and community engagement. | Promotes sustainable forest management, similar to FSC. | Brands using certified wood fiber materials. |
| (Other certifications, like specific regional or national certifications) | (Details vary by certification. May include aspects like water conservation, carbon footprint reduction, or recycled content.) | (Benefits vary depending on the certification’s criteria. May focus on specific environmental concerns.) | (Specific brands and their certifications will vary.) |
Cost and Economic Factors
Sustainable composite decking offers a compelling alternative to traditional wood, but its initial cost can sometimes be a deterrent. Understanding the comparative costs, long-term savings, and regional availability is crucial for informed decision-making. This section delves into the financial aspects of choosing sustainable composite decking.
Cost Comparison of Different Decking Options
Various factors influence the cost of sustainable composite decking, including the specific material composition, manufacturing processes, and the brand. Generally, composite decking materials are priced higher than pressure-treated lumber but often lower than exotic hardwoods. The price difference reflects the added value associated with enhanced durability, low maintenance, and sustainability.
Long-Term Cost Analysis
While the initial cost of composite decking might seem higher than traditional wood, the long-term economic benefits are substantial. The reduced maintenance requirements (e.g., no staining, sealing, or repainting) translate into significant savings over the lifespan of the deck. Furthermore, the durability of composite decking often leads to a longer lifespan compared to wood, further minimizing long-term costs.
For instance, a composite deck can last 20-30 years with minimal upkeep, whereas a wood deck might require replacement every 10-15 years due to rot, insect infestation, and other issues.
Regional Availability and Accessibility
The availability and accessibility of sustainable composite decking materials vary regionally. Factors such as local demand, supplier networks, and government regulations influence the ease of acquiring these materials in different locations. In regions with strong environmental consciousness and a robust supply chain, access to composite decking options is often more straightforward. Conversely, in areas with limited access to specialized materials, the pricing and availability may differ.
Economic Benefits of Sustainable Composite Decking
Beyond the direct cost savings, the use of sustainable composite decking can yield significant economic benefits. The reduced environmental impact and the lower maintenance needs contribute to a positive brand image, potentially increasing property value. Furthermore, the reduced labor costs associated with upkeep translate to substantial savings over time. The longevity of the decking, minimizing replacement needs, also directly impacts the overall cost of home ownership.
Decking Material Cost Comparison
This table provides a general comparison of upfront, maintenance, and overall lifespan costs for various decking materials. Keep in mind that specific costs can vary based on region, material grade, and installation complexities.
| Decking Material | Upfront Cost (per square foot) | Maintenance Cost (per year/per square foot) | Overall Lifespan Cost (estimated total over 25 years) |
|---|---|---|---|
| Pressure-Treated Lumber | $4-$8 | $0.50-$2.00 | $120-$300 |
| Composite Decking (mid-range) | $10-$15 | $0.25-$0.50 | $250-$375 |
| Composite Decking (premium) | $15-$25 | $0.10-$0.25 | $300-$450 |
| Exotic Hardwood | $20-$50 | $1.00-$3.00 | $500-$1200 |
Maintenance and Cleaning
Sustainable composite decking, while low-maintenance, still requires some attention to remain in optimal condition and preserve its aesthetic appeal. Proper cleaning and routine upkeep contribute significantly to the longevity and value of this material. Regular care prevents the build-up of dirt, grime, and mildew, maintaining the decking’s color and structural integrity.Routine maintenance, when performed correctly, extends the lifespan of composite decking, reducing the need for costly repairs and replacements.
This proactive approach minimizes the long-term maintenance costs associated with composite decking.
Routine Maintenance Requirements
Composite decking is inherently low-maintenance, but consistent upkeep is essential for preserving its beauty and performance. This involves a few key tasks. Regular sweeping or hosing down the surface removes loose debris, preventing clogs and potential damage to the decking.
Cleaning Methods and Products
Effective cleaning methods are crucial for maintaining the pristine appearance of composite decking. A gentle pressure washer, using a low-pressure setting, is often sufficient for removing surface dirt and grime. For tougher stains or embedded debris, a mild detergent solution (a mix of dish soap and water) can be used. Avoid harsh chemicals or abrasive cleaners, which can damage the composite material.
Specialized Cleaning Products
Different composite decking types might require specific cleaning products. For instance, decking with a textured surface might benefit from a slightly more concentrated detergent solution to effectively remove embedded dirt. Manufacturers often provide recommendations for appropriate cleaning agents on their product labels. Always refer to the manufacturer’s guidelines for specific cleaning instructions.
Long-Term Maintenance Costs
Comparing the long-term maintenance costs of composite decking to wood decking reveals a significant advantage for composite. Wood decking typically requires regular sanding, sealing, and staining to prevent rot, insect damage, and weathering. These treatments add up over time. Composite decking, on the other hand, often requires only occasional cleaning, resulting in lower long-term costs.
Step-by-Step Guide for Cleaning and Maintaining Composite Decking
- Assessment: Inspect the decking for any noticeable dirt, mildew, or debris build-up.
- Preparation: Gather your cleaning supplies, including a garden hose, a soft-bristled brush (optional), a mild detergent solution, and a pressure washer (if available). Ensure you use a low-pressure setting for the pressure washer to avoid damage to the decking.
- Cleaning: Begin by hosing down the entire surface of the decking to remove loose dirt and debris. Use a soft-bristled brush for stubborn stains or mildew. If necessary, create a mild detergent solution (a mix of dish soap and water) and apply it to the decking, working in sections. Rinse thoroughly with water after applying the solution.
- Drying: Allow the decking to air dry completely before use.
- Maintenance: Regularly sweep or hose down the decking to prevent the build-up of dirt and debris. This helps maintain the decking’s appearance and prolong its lifespan.
Future Trends and Innovations
The landscape of sustainable composite decking is constantly evolving, driven by consumer demand for eco-friendly products and advancements in material science. Future trends will focus on enhancing performance, reducing environmental impact, and creating innovative designs that meet diverse aesthetic and functional needs.
Emerging Materials and Technologies
Innovations in composite decking materials are paving the way for enhanced durability, aesthetic appeal, and sustainability. Researchers are exploring novel blends of recycled materials, incorporating bio-based polymers, and developing advanced manufacturing processes.
- Recycled Plastic Composites: A significant trend is the integration of recycled plastics into composite decking formulations. This approach reduces reliance on virgin materials and lowers the environmental footprint of the product. Examples include decking made from recycled PET bottles or agricultural plastics, demonstrating the potential for circular economy applications.
- Bio-based Polymers: The use of bio-based polymers, derived from renewable resources like plant starch or cellulose, is gaining traction. These materials offer a sustainable alternative to traditional petroleum-based polymers, minimizing the carbon footprint of the production process. Examples include decking incorporating bio-polymers like PLA (polylactic acid) or PHA (polyhydroxyalkanoates).
- Advanced Manufacturing Techniques: 3D printing and other advanced manufacturing processes are being explored for creating customized decking designs. These techniques enable intricate patterns, customized colors, and potentially even on-site fabrication, offering greater design flexibility. A key advantage of this approach is reduced waste and optimized material use.
- Improved Color and Texture Options: Manufacturers are continuously developing new color palettes and textures that better mimic natural wood, enhancing the aesthetic appeal of composite decking. These advancements are expanding the design possibilities and reducing the need for staining or finishing, further contributing to sustainability.
Innovative Designs and Applications
Sustainable composite decking is expanding beyond traditional applications. New designs and functionalities are emerging to meet the demands of modern outdoor living spaces.
- Multi-functional Decking Systems: Composite decking is being integrated with features such as built-in lighting, electrical outlets, and even irrigation systems, creating versatile outdoor living spaces. These features enhance the functionality and value of the decking, addressing the evolving needs of homeowners.
- Integration with Green Roofs and Walls: Composite decking can be seamlessly integrated with green roof and wall systems, fostering sustainable landscaping and creating aesthetically pleasing and eco-friendly outdoor environments. This integration offers multiple benefits, including improved insulation, water management, and enhanced biodiversity.
- Decking with Enhanced Durability and Weather Resistance: Advanced formulations are being developed to provide superior resistance to UV degradation, moisture, and extreme temperatures. These improvements will contribute to longer product lifecycles, reducing the need for replacement and lowering the overall environmental impact over time.
Market Opportunities and Challenges
The sustainable composite decking market presents significant opportunities for growth and innovation. However, challenges related to cost and consumer acceptance remain.
- Consumer Acceptance and Education: Consumers need to be educated about the benefits of sustainable composite decking, including its environmental advantages, durability, and design flexibility. Marketing campaigns focused on showcasing the long-term value proposition of these products can be crucial.
- Cost-Effectiveness: While the long-term cost-effectiveness of sustainable composite decking is often favorable compared to traditional materials, the initial cost can be a barrier for some consumers. Manufacturers are exploring methods to reduce production costs without compromising quality or sustainability standards.
- Regulatory Support and Incentives: Government policies and incentives that encourage the adoption of sustainable building materials can significantly impact market growth. Regulations that promote the use of recycled and bio-based materials would stimulate market development.
- Supply Chain Sustainability: Ensuring the sustainability of the entire supply chain, from raw material sourcing to manufacturing and product disposal, is crucial. Transparency in supply chain practices is critical to building consumer trust and promoting sustainable practices throughout the industry.
Closure
In conclusion, sustainable composite decking provides a compelling alternative to traditional wood, combining aesthetic appeal with environmental consciousness. By understanding the materials, manufacturing processes, performance characteristics, and design considerations, you can make informed choices that align with your sustainability goals and architectural preferences. This guide has explored the crucial factors to consider when selecting and installing sustainable composite decking.
Questions Often Asked
What are the common types of sustainable composite decking materials?
Common materials include wood-plastic composites (WPC), recycled plastic composites, and other engineered materials. Each type varies in composition and performance characteristics.
What are the typical maintenance requirements for composite decking?
Composite decking generally requires less maintenance than traditional wood. Regular cleaning with soap and water is usually sufficient, with occasional pressure washing for heavier soiling. Specific cleaning products may be recommended by the manufacturer.
How does the cost of sustainable composite decking compare to traditional wood decking?
Initial costs of composite decking can vary, but long-term maintenance and replacement costs are often lower than those of traditional wood. Factors like the specific material, brand, and region of purchase can affect the overall cost.
What are the key certifications for sustainable composite decking?
Look for certifications like Forest Stewardship Council (FSC) for responsibly sourced wood, or Greenguard for low chemical emissions. These certifications can ensure the decking meets specific sustainability criteria.
