nized steel is often the motivating factor for changing out entire plumbing systems in older homes because of corroded galvanized piping. In addition to internal corrosion, which causes restricted water flow, other metals used in valves and fittings can cause galvanized steel to corrode more rapidly. Cross-Linked Polyethylene (PEX) is a
flexible plastic pipe that is highly freeze- resistant and allows for fewer fittings than rigid piping systems. “Fewer fittings means less pressure loss.” says Shawn Martin, direc- tor of industry relations for the Plumbing, Mechanical & Fuel Gas group of the Inter- national Code Council. “This may make it possible to drop the pipe size, reducing the enclosed volume.” PEX has a high durability and low corrosion because of its complex molecular formulation. However, PEX must be kept out of direct sunlight, as ultraviolet radiation degrades it over time. Other materials include PE-RT (just
Here’s a quick overview of material types to help get you started on your own evaluation of pipes and fittings: Polyvinyl Chloride (PVC) is a plastic
material frequently used for water service to the home from the main, swimming pools, and sprinkler drain systems. PVC contains phthalates, which are controversial in terms of long-term health effects, particularly in infant exposure. Although it’s unclear whether the use of PVC piping can increase human exposure to phthalates to a signifi- cant degree, PVC has other issues. Lead is sometimes used as a hardening agent in PVC during the manufacturing process. On the positive side, Chlorinated PVC (CPVC) offers better corrosion resistance in situations with high acid water. Copper is one of the most commonly used
piping materials because of its availability and durability. Copper can corrode in the presence of high acid water and like PVC, may contain lead. States like California and Vermont have dramatically lowered the lead permissible in plumbing fittings down to 0.25%. Galvanized Steel isn’t commonly used
anymore because of its high tendency to cor- rode and short service life. As many home- owners and remodelers can confirm, galva-
approved for use in the 2012 International Plumbing Code), polypropylene, and polyeth- ylene.
Hot Water: Waste Not Water and energy efficiency hinges on the amount of water used for tasks. Using low-flow fixtures and proper use configura- tions can significantly improve plumbing system efficiency. The easiest way to select good fixtures is to follow some of the well- established fixture efficiency guidelines, like the EPA’s WaterSense labeling program, which requires that labeled fixtures provide a measurable, third-party certified 20% improvement in efficiency over average
October 2010 GreenBuilder
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