Homeowner demand for decking and railing products is poised to continue its steady rise through 2015 at an annual rate of 4% to value $4.1 billion that year. While demand for synthetic and metal boards and rails is expected to grow faster than that for wood, the historical market front-runner will likely hold its lead and market share.

The news comes from Malvern, Pa.-based consulting firm Principia’s 2013 survey of more than 750 homeowners, dealers, and other industry experts about their buying and selling decking and railing. In its report, the company projects 13% growth in demand for each of wood decks and railings from 2012 to 2015.

Demand for synthetic decking should grow 14.5% through 2015 while synthetic railings are expected to see demand grow approximately 13% for the same period. Metal decking, still the smallest of the categories at less than 1% of demand in 2012, will grow 22% to value $11 million while retaining its current market share. Metal railing demand will grow nearly 20% during the same period, the survey says, and increase its market share from 12.4% to 12.6%.

The data also includes a market snapshot for 2012. That year, pressure-treated decking led the market with demand for boards worth $932 million and demand for railing worth $696 million; demand for wood substructures totaled $801 million that year. Cedar decking valued $237 million in 2012, while cedar railing demand tallied $172 million. Composite boards saw demand of $677 million and composite railing $151 million during 2012.

Wood accounted for approximately 62% of the decking market and railing market each in 2012. It’s expected to hold that share through 2015. The market for synthetic products should, too, hold its shape through 2015—synthetic boards accounted for nearly 36% of the market and synthetic rails for 26% of the market in 2012 and are expected to do the same in 2015. Metal boards should stay at 0.4% of the market through 2015 while metal railing demand is expected to experience an uptick of less than one percentage point during that time.