What pipe should be used for grey water?

Author: Ressie Boehm  |  Last update: Thursday, November 6, 2025

Plastic pipe systems are ideal to handle and contain gray water that may have a variable composition.

What pipe to use for grey water?

Lilac Low Density Poly Pipe - 50m Roll. High quality poly pipe to be used with low density poly fittings. This pipe is only rated for use in non pressure irrigation systems and the lilac colour signifies grey water use.

What size pipe is used for GREY water?

Blackwater drain pipe from toilets is usually 3 inches (75 mm) in diameter, while drain pipe from greywater sources, such as bathroom sinks or showers, is usually 1.5 inches or 2 inches in diameter.

What is the grey water pipe called?

Polybutylene pipe, or Poly-b as it's often called, is a grey plastic pipe that was manufactured from the late '70s until the late '90s and used heavily in residential plumbing systems during that time.

Can grey water go into a rainwater pipe?

Gutters and gullies should only collect rainwater and connect to the rainwater drain. Wastewater pipes should not be connected to the rainwater system. If the rainwater gutters and gullies are connected to the wastewater drain, rainwater could overwhelm the drain and cause flooding.

Plumbing System-Latest Grey Water Technology

Where should grey water drain to?

best practice is for grey water to terminate at a tree or flower bed under the surface in a french drain type setup with gravel and sand and a perforated pipe under the surface with 6-12" soil and plants above.

What is the best way to deal with GREY water?

Basic Greywater Guidelines
  1. Don't store greywater (more than 24 hours). ...
  2. Minimize contact with greywater. ...
  3. Infiltrate greywater into the ground, don't allow it to pool up or run off (knowing how well water drains into your soil (or the soil percolation rate of your soil) will help with proper design.

Should I use copper or PEX?

With a life span that's 20 to 30 years longer than PEX pipe, copper is the clear winner. Properly maintained copper pipes can be expected to last 50 to 70 years. PEX pipes that are properly maintained generally last for 25 to 50 years.

Is grey pipe PVC or CPVC?

In terms of appearance, PVC pipes are white or dark gray in color, and CPVC pipes are usually off-white, light gray, or yellow.

Will homeowners insurance cover polybutylene pipe?

In general, insurance companies do not provide coverage within homeowners insurance policies for polybutylene pipes. They are simply too much of a liability as they are easily damaged and will break down, burst, and damage the home.

How deep should grey water pipe be?

I first dug a trench for the grey water system drainage pipe. For our zip code, one would normally go down at least 4 feet deep to protect pipes from freezing and cracking below the frost line.

What kind of pipe should I use for water?

Copper pipes remain popular among plumbers and homeowners alike because they are corrosion-resistant and best suited to protect the quality of the water. Copper pipes are able to handle high water pressure and are tolerant of both hot and cold water temperatures.

Where do you drain gray water?

Whenever possible, dump your RV gray water at a dump station or sewage facility. Avoid contributing to environmental pollution by using biodegradable products. It's also a great idea to use a strainer to strain out any food particles if you dump your gray water on the ground to avoid attracting wildlife.

How do you connect GREY water?

You can connect a greywater hose to your washing machine water outlet. Place the other end of the hose outside to pump water onto your lawn and garden. Ensure the hose is within your property and your garden requires watering to ensure there is no run-off.

Why is CPVC not used anymore?

Fragility and Brittleness. ASTM F441 CPVC pipes can become brittle over time, particularly under stress or extreme temperatures. This brittleness makes them more prone to cracking and failure. In colder climates, this issue is exacerbated as pipes can freeze and break easily.

What plumbing pipe is GREY?

Beware of gray pipes: Polybutylene is a gray tube that carries potable water through many homes. PB is pretty much the only gray water pipe ever installed in homes. PB tubing found in homes will have a dimeter of 1/2 inch, 3/4 inch, or 1 inch.

Is gray PVC pipe safe for drinking water?

Gray PVC pipes are primarily used for the transportation of non-potable (non-drinking) water. These pipes are often used in industrial applications, as well as for underground irrigation systems.

Why do plumbers not use PEX?

Material Concerns: One of the primary concerns about Pex plumbing is the material itself. While Pex pipes are undoubtedly flexible, making them easier to install in tight spaces, they are not as durable as traditional materials like copper or even PVC.

Why do plumbers not use copper anymore?

It has become expensive, can still corrode based on pH levels of water, and in cold climates, frozen water can cause copper pipes to burst.

What is the downside of PEX?

Like any other material, multiple factors could lead to problems with PEX. Some of these factors could be simple over-chlorination of the water running through it or dezincification, which could weaken and break down the fittings used on the piping. Another issue could be the piping failing to pass a pressure test.

What not to put in a grey water system?

Toxic discharges such as rinse water from paint, chlorine bleach, or hair dye should never be released into the greywater system. Instead, they should be routed to the municipal sewer. All greywater systems should have a three-way valve installed to easily switch the discharge water flow to the sewer or yard.

What are the three types of grey water systems?

There are three types of greywater systems - Laundry-to-Landscape (L2L), Simple, and Complex greywater systems.

What to do when grey water is full?

Open the Tank Valve: Do this slowly to manage the flow and prevent any backsplash. Ensure Complete Drainage: Allow the tank to empty fully, which could take several minutes depending on the size.

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