• Introduction
• Uses
• Types
• Economic Considerations
• Government Procurement

Recycled plastic lumber (RPL) is a wood-like product made from recovered plastic or recovered plastic mixed with other materials and can be used as a substitute for concrete, wood, and metals.

It is an excellent material for decking, landscaping and recreational equipment and can also be used in many structural applications.

• Agricultural. Ranch fences, gates, animal stalls.
• Civil Engineering. Retaining walls, sound barriers, car stops, walkways, railings.
• Gardening. Fences, flower planters, compost bins, landscape timbers.
• Industrial. Flooring, pallets, truck flooring, side rails.
• Recreational. Park benches, picnic tables, playground equipment, informational kiosks, wetlands walkways, decking, park bridges, flower bed borders.
• Transportation. Noise barriers, sign posts, guard rail offset blocks, car stops, speed bumps.
• Marine Engineering. Piers, pilings, seawalls, and bulkheads, boat docks.
• Other. There are many more uses for recycled plastic lumber and even more to be discovered.

Non-Structural / High Density Polyethylene (HDPE)
This type of RPL consists of up to 95 percent of HDPE (The same material used to make plastic milk jugs). It is available in colors, is colorfast, is UV stable, is non-absorbent, has a 50 year warranty and is well suited for decking and landscape applications. It is manufactured with a solid core as extruded or molded and with a hollow core as extruded.

Structural / Fiber-Reinforced
Fiber-reinforced RPL consists of plastic mixed with chopped or continuous strands of glass fiber. It is stiffer than non-structural RPL, is colorfast, is UV stable, is non-absorbent, has a 50 year warranty and is well suited for support structures. It is available as extruded or molded.

Industrial / Commingled
Commingled RPL is made from mixed recovered thermoplastic (plastic that can be remelted and remolded). Primarily consisting of 80-90 percent polyethylene(PE). It has the lowest cost because sorting of the raw material is reduced or eliminated. It is well suited for decking and landscape applications. It is available as molded.

Composite / Wood-Filled
Wood-filled RPL is made of plastic mixed with sawdust or other recycled fiber, usually a mix of 50 percent polyethylene (primarily low-density polyethylene or LDPE) and 50 percent sawdust or other recycled fiber. It has the fewest voids, good traction and is paintable. It will absorb stains if left natural and it has only a 20 year manufacturer's warranty.

Other combinations of materials
Many other combinations of materials are possible, each with different properties, costs and applications. Some other formulations include:

• Glass-reinforced plastic lumber.
• Rubber-plastic lumber.
• Mixed plastics and peanut shells.
• Coextruded steel liner (e.g., metal pipe).
• Coextruded steel reinforcing rods.
• Multiple laminations of oriented HDPE.
• Reinforced concrete fill.
• Cross linking of PE molecules by thermoset processes

Advantages over wood

RPL is clean, nontoxic, and nonporous, and lasts longer than wood. In addition, all types except wood-filled RPL have the following advantages over wood:

• Moisture and chemical resistant.
• Graffiti resistant.
• Splinter free, does not crack.
• Does not need sealants or preservatives.
• Colored throughout, does not need paint.
• Impervious to insects.
• Flexible, can be curved and shaped.
• Maintenance free.
• Does not absorb bacteria.
• UV stable.

Benefits of RPL to the community

• Saves money for local governments and other purchasers by lowering long-term maintenance costs.
• Creates additional business opportunities.
• Diverts plastic waste from landfills.
• Reduces wood waste, especially treated wood waste.
• Helps local governments reduce landfill requirements.

RPL currently has a higher purchase price (initial cost) than virgin wood, but lasts longer than wood. When maintenance, replacement, and life cycle costs (materials + installation + finish + disposal) are included in the analysis, RPL products can cost less than wood if the structure is designed properly. Also, plastic lumber is again recyclable at the end of its useful life.

Purchase prices of RPL are expected to decrease as technology improves and demand increases. Wood prices are expected to continue to increase.

The Resource Conservation and Recovery Act mandates a federal "buy recycled" program that requires the United States Environmental Protection Agency (U.S. EPA) to designate products made of recovered material as suitable for purchase by federal agencies. As a result of this mandate, U.S. EPA prepares an annually updated set of comprehensive procurement guidelines and a Recovered Material Advisory Notice that recommends the practical recycled-content level of the materials. Click here for more information.

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