What Is A Riser In Plumbing?

Last Updated On November 20, 2022
what is a riser in plumbing

What is a riser in plumbing? A riser is a vertical pipe that carries water to a higher level. It is used to raise the water supply to fixtures such as toilets, sinks, and showers

In some cases, you may need to install a riser if the plumbing system in your home does not provide enough pressure for certain high-demand fixtures.

In this blog post, we will discuss what vertical risers are, when you need them, and how to make them according to the building code. We will cover:

  • What you need to know about a riser in plumbing
  • Situations that require a plumbing riser
  • Different types of risers
  • Building code requirements for plumbing risers

What's In This Guide?

      What You Need to Know About A Riser in Plumbing

      A riser is a vertical pipe typically found in a building’s walls that carries water from a supply line to a higher level and properly disposes of the wastewater. 

      They are commonly used to support fixtures such as toilets, sinks, and showers on the upper floors of a larger home or multi-dwelling unit. 

      In a typical setup, you’ll have the main riser pipe and then riser branches that will lead to each fixture grouping with a dedicated valve at each grouping. 

      Your plumbing contractor will create a riser diagram early in the construction stage so that they can plan the most efficient system possible.

      Risers typically use a  minimum pipe size of ¾”, but plumbers may use larger pipes depending on the number of fixtures involved. 

      Risers typically contain backflow preventers that prevent water from moving in the wrong direction, preventing water contamination. They may also include a water hammer arrestor to ensure proper airflow.

      Riser pipes can be made from either plastic or metal. Metal pipe, especially copper pipe, tends to last longer than PEX pipe or PVC pipe, especially when transporting hot water from your water heater. However, plastic pipe offers more flexibility. 

      Did You Know? Copper pipe is the preferred material for plumbing risers despite its high price tag due to its strength, and longevity, especially for safety-related dry risers that provide water in the case of a fire. 

      did you know what is a riser in plumbing

      Situations That Require A Riser

      Most commonly, you will use a plumbing riser when you need to transport water from one floor to a higher floor.

      You may also need to install a riser if the plumbing system in your home does not provide enough pressure for certain high-demand fixtures. For example, if you have low water pressure in your shower, you may need to install a riser to raise the water supply to the plumbing fixture.

      Additionally, risers provide the fire department with access to water in the case of an emergency. Building code requires a riser for this exact purpose in residential buildings, apartment buildings, and commercial buildings alike.

      You will also need a riser if you need to transport water far distances, such as with your sprinkler system.

      Signs You Need Riser Repair 

      Risers may require replacement after a number of years, just like the other pipes. 

      Signs that you require riser replacement include:

      If you have a leak, you may be able to fix it yourself if you have access to the leak. Slab leaks located under the concrete slab are much more difficult. 

      If you need to replace the pipe, you will often need to enlist the services of a professional plumber.

      Different Types of Risers

      There are a couple of different types of risers you can find in a building, primarily a dry riser and a wet riser. 

      A dry riser is a riser specifically designed for fire fighting purposes in buildings 60 ft. tall and higher. It will have a street-level access point generally protected in a steel or otherwise durable box and a glazed door. It doesn’t handle daily plumbing functions, meaning it’s dry most of the time. 

      A wet riser constantly transports water from a pump or a tank in buildings 200 ft. and taller. Wet risers require more maintenance than dry risers since they get significantly more use.

      Building Code Requirements For Plumbing Risers

      There are certain codes that you must follow when making a riser. These codes are in place to ensure the safety and functionality of your home and plumbing system. 

      Plumbing risers must be made from a certain material and installed according to strict specifications regarding size, angle, and other considerations. You also need to be aware if you have an electrical riser, as you don’t want to create a fire hazard or damage either system.

      To learn more about these codes, we recommend consulting with a professional plumber or contractor. They will be able to help you select the right materials and install the riser correctly.

      Do not attempt to install or replace plumbing risers yourself. Only licensed plumbers can apply for the permit.

      Frequently Asked Questions Regarding Plumbing Risers

      What is a riser in a water system?

      A riser in a water system refers to a vertical pipe that transports water to a second story. 

      When do I need a riser?

      You need risers whenever you need water to reach a higher floor. You may also need a riser if the current system doesn’t create enough pressure to transport the water upward naturally. 

      What are the types of risers?

      The main difference between different types of risers involves the material it’s made from. Plastic risers may not connect to the copper tubes and won’t last as long as metal risers, but they cost less and offer more flexibility.

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      About Plumbing Navigator

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      We write about “all things plumbing,” helping you navigate common questions, repairs, and the best plumbing products on the market.

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