Quick Definition

The series of pipes that deliver water or remove waste to and from the house

In Depth

A home’s clean water supply and waste pipes are connected to the city’s water supply system, or city main, located under the street in front of a home. The clean water supply is connected to a water meter and runs through a series of pipes which feed exterior faucets, toilets, sinks, dishwashers, icemakers, tubs, showers, clothes washers and fire sprinklers.

The clean water supply is pressurized so that water can be fed up into houses which sit above the city main (located under the street). Waste water is typically gravity-fed – the weight of the water and waste carries it back into the city’s waste pipes.

Clean water supply pipes can be made in various materials:

  • PVC - Polyvinyl Chloride (PVC) is a man-made plastic. PVC is widely used because of its relatively low cost, availability and ease of installation. Dioxins, plasticizers and known carcinogens are found in PVC.
  • Copper – Copper was the main source of piping before plastic was introduced. The cost of copper has risen drastically in recent years, making copper piping very expensive to install. Make It Right only uses copper on the exterior faucets of our homes.
  • Galvanized Steel – Galvanized steel used in plumbing is covered in a protective layer of zinc. Galvanized steel was used in many homes before the 1960s when plastic became popular. Galvanized steel is prone to corrosion and is not used much today.
  • PEX – PEX is Cross-Linked Polyethylene, a man-made plastic. This type of piping is popular in newer homes because of its flexibility; PEX can bend 90 degrees without joints. PEX can also be run through the house in long lengths, so there’s no need Coupling. Make It Right currently uses PEX from Uponor, for its affordability and easy installation.

Waste water pipes can also be made in various materials:

  • PVC - Polyvinyl Chloride (PVC) is a man-made plastic. PVC is widely used because of its relatively low cost, availability and ease of installation. Dioxins, plasticizers and known carcinogens are found in PVC. Even though waste water does not directly come into contact with homeowners, the toxins in the waste water can leach into the ground and stay in the water supply even after its been treated.
  • Cast Iron – Cast iron pipes have not been widely used since the onset of plastics.
  • ABS – Acrylonitrile-Butandiene-Styrene (ABS) is a thermoplastic resin. ABS is affordable, easy to install and resistant to corrosion. Make It Right uses ABS for all of our waste piping and vent stacks.

Our Application

From our first homes, we have used PEX for clean water supply lines. PEX is flexible and easy for us to install within the Floor Framing. We run PEX through I-Joists with pre-manufactured knock-out holes. Because PEX needs fewer joints than other piping, it also needs less maintenance – an important factor when building for low-income communities.

In an effort to reduce water usage, in all of our homes we use low flow faucets and showerheads, and our toilets are dual flush. “Low-flow fixtures reduce water flow by increasing water pressure and mixing air with the water as it comes from the tap. You can purchase low-flow fixtures for as little as $10 each and achieve water savings of 25 to 60 percent from faucets and showerheads (Yudelson).” See our Product List to learn more about these fixtures.

Lessons Learned

While materials, fixtures and appliances are all important, the structure of the house is most critically impacted by the plumbing systems. We have worked closely with our plumbing supplier Uponor, framing consultants and engineers to ensure that supply and waste lines do not conflict with our structural members. Sometimes this means we need to shift our framing several inches to accommodate fixtures. By coordinating these changes before construction, we save time and cost associated with structural conflicts.

We would like to use water collected on the roofs of our houses to use for flushing toilets. Due to New Orleans city regulations, Grey Water is not allowed inside houses. On our first 25 homes, we installed concrete cisterns under our homes to collect rainwater. Homeowners used the water collected in their cisterns to wash cars and water the lawn. Unfortunately, we also had to stop installing cisterns at the request of the city. We are hopeful that New Orleans will change legislation on these water conservation issues in the future.