Demand for behind-the-wall plumbing products is projected to advance 6.5 percent annually to $12.4 billion in 2020.

Behind-the-wall plumbing products comprise the pipe and fittings used in water distribution and drain, waste, and vent applications, as well as those items used in fire suppression systems, such as valves and fire sprinklers.

Behind-the-wall plumbing product demand will receive a general uplift from expanding building construction activity. According to senior analyst Matt Zielenski, "Design trends that call for homes and businesses to have multiple and larger bathrooms with more fittings will boost demand for distribution and DWV pipe to carry water to and from supply and sewer mains."

Among the different pipe materials, PEX and PVC will see the strongest growth in demand through 2020, fueled by their low cost and ease of installation. These and other trends are presented in Behind the Wall Plumbing, a new study from The Freedonia Group, a Cleveland-based industry research firm

Demand for pipe, which accounts for the largest share of the behind the wall plumbing product market, will approach $7.7 billion in 2020. Gains will be supported by new building construction and by the rising numbers of homes and businesses with multiple bathrooms.

In many cases, the locations of bathrooms will necessitate longer pipe runs to connect fixtures to water supply and disposal lines. Increasing demand for such amenities as radiant floor heating, his-and-her vanities, and whirlpool bathtubs will also promote pipe demand, as these features require their own plumbing pipe lines.

Sprinklers and fittings are anticipated to see the fastest gains in nonpipe behind-the-wall plumbing products demand. Growth in construction of sprinkler-intensive buildings such as offices and healthcare facilities will support demand for sprinklers.

Further boosting value gains will be growing use of higher-priced components such as Early Suppression Fast Response sprinklers. Among fittings, the increasing length and complexity of pipe networks will boost the use of couplings to connect pipes of varying diameters, and tees and elbows to change the direction of pipe runs.

Demand for pipe supports will rise as clamps and hangers are added to PEX pipe installations to ensure consistent flow rates.