InstaBidsWhat is composite decking?
Composite decking is an outdoor board material made by mixing wood particles with plastic resin and additives. It is also called wood-plastic composite, or WPC. It is generally not designed for painting or staining. When planning installation, ask for side and end gaps that allow expansion and drainage.
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What this means for your home project
- Obtain the board’s material description and confirm whether it identifies wood mixed with plastic resin and additives. Source: Washington State University, read 2026-11-02.
- Ask the installer to list side and end spacing in the written scope, explaining how the layout permits expansion and drainage. Source: Washington State University, read 2026-11-02.
- Ask for corrosion-resistant fasteners to be named in the written scope so the proposed fastening choice is explicit. Source: Washington State University, read 2026-11-02.
- Obtain the decking manufacturer’s care guidance before deciding whether power washing belongs in the maintenance plan. Source: Washington State University, read 2026-11-02.
- Describe it onceBy chat, or through your own AI assistant, and add photos.
- Post it and send itContractors bid in writing on that scope.
- Compare line by lineEvery quote is written against the same scope.
- You chooseContact details stay hidden until you pick and they confirm.
For your AI assistant
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https://instabids.ai/intake?from=glossary-composite-decking&page_type=glossary&job=Install+wood-plastic+composite+decking+with+written+board%2C+spacing+and+fastener+specifications&utm_source=us&utm_medium=page&utm_campaign=glossary - Prompt for any AI, with your job
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How does composite decking compare to natural wood? Is composite that much better?
Composite trades some strength for a different care routine. Natural Resources Canada describes wood-plastic composites as weaker than solid or composite wood products; it also says they need periodic cleaning and can fade. Its material profile is Canadian guidance, not a US structural design rule. Compare the care requirements alongside the board specification. “They are not as strong as solid or composite wood products.” Source: Natural Resources Canada, read 2026-11-02. “They are considered to be relatively low maintenance, but their colours do fade because of sun exposure and they require periodic cleaning, often with a pressure washer.” Source: Natural Resources Canada, read 2026-11-02.
Can WPC decking be painted or stained?
Usually, no: Washington State University says wood-plastic composites are generally not designed for painting or staining. Choose the board with that limitation in mind rather than planning to change its finish later. WPC means wood-plastic composite; this guidance concerns that material family. “WPCs are generally not designed to be painted or stained.” Source: Washington State University, read 2026-11-02.
Do I need to make sure there is a gap between my Decking Boards?
Yes. Washington State University says gaps between board sides and ends allow thermal expansion—movement as temperature changes—and drainage. Its general recommendations are at least 1/8 inch at ends and 3/16 inch at sides. Ask the installer to state the chosen board’s spacing requirements in the written scope. “Ensure proper spacing between sides and ends of boards during installation to allow for thermal expansion and facilitate proper draining.” Source: Washington State University, read 2026-11-02.
Can you power wash composite decking?
Check with the board manufacturer before power washing. Washington State University allows for that cleaning method but explicitly recommends consulting the manufacturer. Ask for the care instructions for your exact decking before deciding how to wash it. “WPC decks can be power washed; however, it is recommended to check with the manufacturer” Source: Washington State University, read 2026-11-02.
Can composite decking rot?
Yes, fungal decay is possible in wood-plastic composites. USDA’s 2024 research summary describes moisture-related movement creating tiny cracks in the plastic around the wood, giving decay fungi access. That research describes a failure mechanism; it does not predict the remaining life of an individual deck or establish that every board will decay. “It appears that after an initial period of outdoor exposure, stresses resulting from moisture-induced expansion of wood particles create microcracks in the plastic matrix, ultimately providing decay fungi access to the wood component of WPCs.” Source: USDA Forest Service, Forest Products Laboratory, read 2026-11-02.
Sources
- Consumer information on wood-plastic composites — Washington State University; read 2026-11-02.
- Maintenance information for WPC products — Washington State University; read 2026-11-02.
- Fungal and moisture durability of wood–plastic composites: summarizing 20 years of Forest Products Laboratory research — USDA Forest Service, Forest Products Laboratory; published 2024; read 2026-11-02.
- Wood-plastic composites — Natural Resources Canada; read 2026-11-02.