

What is Trex?
               Trex is  a wood substitute, made from wood and plastic fibers, often used for decking,  railing, fencing, and trim. The plastic and wood comes from reclaimed or  recycled resources, like used pallets from woodworking operations, sawdust, and  recycled grocery bags. Trex screens all materials to make sure only the highest  quality ingredients go into the Trex factory. By using this process, Trex keeps  thousands of wood scraps and plastic out of landfills each year and takes pride  in what the company calls “environmental responsibility.” It also gives a  building coveted LEED points.
            The Trex  style provides a higher level of comfort and performance, in that Trex doesn’t  rot, splinter, or warp, and you will never have to stain or paint it for upkeep  purposes.  Many customers think that Trex  decking looks beautiful, and they love walking around it with bare feet with no  risk of splinters. 
            Remember, decking is exposed to the  elements – weather and climate alone is going to generate some wear and tear. It  also is slip resistant, won’t be damaged by insects, has a natural look that no  other composite is able to match, offers the widest range of textures, styles,  and colors, is easy to fasten and cut, and finally, has an industry-leading  warranty for residential and commercial products. 
            It’s  true that Trex is more expensive than wood (by about 30%), but that is because  you pay for what you get; with Trex, you’re paying for the highest quality wood  composite. And since the maintenance costs are so minimal, value is quickly  gained over time. According to Trex’s website,  after four years, “the total cost of owning a Trex deck equals the cost of a  pressure-treated wood deck. And over the life of the purchase, Trex offers a  greater value than wood.”
            Most  customers agree – Trex decking, while a bit more expensive, will most likely  save you money in the long run. It looks like wood and feels like wood, but you  won’t have to replace it because of wood rot or warping, like you eventually would  with wood. 
Sources:
            http://www.trexpartners.com/faq
            http://improvementweb.com/composite-decking-vs-wood-decks/49/
            http://community.cookinglight.com/showthread.php?t=89884
            http://www.ehow.com/about_6367411_trex-decks-vs_-wood-decks.html