• The best composite decking is more durable and easier to maintain than wood decking.Relaxing Deck image by gardenia from Fotolia.com
  
  A deck adds value to your home and gives you a place to enjoy the great outdoors, but it's also exposed to more wear and tear than the surfaces in your home. Redwood and cedar have always been popular decking choices, but cost and scarcity have opened the door to composite decking. These plastic-wood hybrids come in hollow and solid profiles, and the best ones are more durable and require less maintenance than wood decks. Here are the three primary types.
  
  

Polyethylene-Based

• According to greenhomeimprovement.com, "Polyethylene decking composites have the biggest share of the composite decking market." This decking combines polyethylene with wood fibers to produce decking that greenhomeimprovement.com considers the best wood-like synthetic. Although this soft plastic works well for producing decking that looks and feels like wood, it lacks the strength, stiffness and resistance to compression and expansion that other plastics have. It does, however, resist stains and weathering better than other composite materials.
  
  

Polypropylene-Based

• Polypropylene is a hard plastic that's overtaking polyethylene in popularity. Writing for deckmagazine.com, Scott Gibson says its strength and stiffness allows it to span a distance that's 50% greater than what polyethylene can do. Polypropylene composite decking is made from virgin or recycled polypropylene mixed with finely ground wood fibers, called wood flour, to create a composite that looks like wood without the upkeep and durability problems. Since polypropylene is more susceptible to weather damage and surface oxidation than polyethylene, additives and stabilizers are needed for UV protection.
  
  

Polyvinyl Chloride (PVC)

• When asked to compare polyvinyl chloride to polyethylene and polypropylene, Forest Products Laboratory research chemist Nicole Stark responded, "The strongest and stiffest of the three is PVC." Even though PVC is more stable than the other plastics, however, it's still vulnerable to weathering and UV breakdown, so additives are included with the wood fibers to protect it from damage. Temperature expansion and contraction are also problems with PVC, so if you want to avoid sheared screws and joints that flex out of alignment, you should take this into account when you install it. You should also be aware that dangerous byproducts are produced during PVC's manufacture, so if it catches fire it will release hazardous toxins. For those who care about the environment, this might be a concern.