The decking and railing market is expected to grow to $3 billion by 2020, up from $1.7 billion in 2015, with a compound annual growth rate of 12.6%. Polypropylene composite decking and railing will show the most growth even as polyethylene maintains an overall lead. Polyethylene (PE) still has the majority share of the market, with North America remaining a stronghold. PE costs less than polypropylene (PP). High-density PE resin used in decking and railing is both strong and stiff, making it ideal for residential use where 16-inch-on-center joist spacing is common. PP is the second most commonly used resin. It's resistant to thermal expansion and contraction, has better creep resistance, and isn't as slippery as PE decking. And because PP is stiffer than other plastics, it can be used to make longer deck boards. For those reasons, according to this forecast, polypropylene will show the highest growth rate over the next five years. Read More