It may be hard to believe, but limitations still exist on the use of plastic pipe in plumbing systems. Some of these limitations are in areas of the country that may shock you. If you guessed New York City, Chicago and San Francisco, you are correct. All three of these metropolitan cities have some crazy plastic pipe limitations. New York City does not allow plastic pipe for water piping anywhere. Plastic pipe can only be used in DWV systems in residential buildings up to five stories high. In commercial construction, plastic pipe is prohibited in all applications. Chicago is actually more restrictive than New York City. The use of plastic pipe for water systems is limited to CPVC for secondary or reclaimed water piping systems. Otherwise, plastic pipe is not permitted for water distribution systems, even in single-family dwellings. For DWV, Chicago limits plastic pipe to residential buildings three stories in height or less. Of course, you have to remember Chicago requires lead and oakum joints for all cast iron inside the building. No-hub still isn’t permitted. San Francisco allows plastic water piping but limits it to DWV systems in buildings no more than two stories high. Hence, San Francisco has the most restrictive height limitation. However, unlike New York City and Chicago, it allows plastic pipe in commercial construction within the two-story limitation. If you thought Los Angeles was in the mix, it removed many of its plastic pipe limitations a number of years ago. A few still exist but none similar to NYC, Chicago and San Francisco.