Important Plumbing Codes: What You Need To Know
Plumbing is a tricky part of DIY projects that is often unavoidable. Whether you’re remodeling a kitchen, bathroom, or laundry room, at one point, you’ll deal with it. Plumbing codes for DIY work are important for plenty of reasons. These codes help create a safe, healthy, and efficient home.
There are thousands of plumbing codes. Some codes are national, but there are also some local ones that you should keep in mind. Sometimes, the local plumbing code is more strict, so you have to be careful. Codes can be confusing, so we’re here to help you sort through it all. Check out the most important plumbing codes to follow with your upcoming projects.

Common Codes

The majority of common plumbing codes relate to the proper venting of drain lines. Without vented lines, they will not drain as efficiently as possible. This can also lead to stinky smells and gases entering the home, so you need to keep venting at the front of your mind.

Here’s a list of the most common codes to consider:

  • DO NOT install fixtures too close to each other.


  • Be sure to use the correct pipe size for vents, drains, and supply lines. This is crucial for efficiency and output based on the size of your home.
  • Decide what material you’re going to use. This is ultimately up to you, but you can choose from materials like PEX, copper, or PVC. Determine the correct pipe materials.
  • When installing or replacing plumbing, it must not weaken the home’s structure. If the inspector suspects compromise in structure, they may require you to reinforce certain areas.

More Important Plumbing Codes To Follow

If you’re doing some home renovations or a simple DIY plumbing project, follow these codes. Following these will make for a smooth process for everyone and save you time in the long run.

Proper Slope In Drainpipes

Undoubtedly one of the most important rules to follow when installing new drain lines is to properly slope them. If you don’t slope your drain pipes enough, you can end up with a clog, backflow, or worse—no drainage at all.
Across the board, the suggestion is at least 1/4″ of drop per linear foot of line.

Purple Primer

One of the most common mistakes that inspectors point out is the lack of purple primer used. Pipes that have glue without purple primer will leak. Before you couple two PVC pipes, be sure to prime them with a purple primer. The purple color allows the inspector to be able to tell if the pipes have been correctly primed.

Use The Right Fittings

When planning your plumbing project, make a list of all proper fittings. You want to do this in order to follow national and local codes. For example, you will need to use special fitting like a closet bend to allow for proper drainage and water flow. If you fail to use the correct fittings, the inspector may make you go back and replace them.

Don’t Cut Notches In Joists

If you’re working in an attic or crawlspace, avoid cutting a notch in joists. Instead, you need to make a clear hole through the joist with something like a hole saw. This does not undermine the strength and integrity of the joist like cutting a notch does.
If you compromise a joist, the inspector might require reinforcement.

Install Drain Line Cleanouts

A drain cleanout is a fitting that you install at different points in a drain line so that you can unclog it. There is usually a cap that you can take off so that an auger can be inserted. This is convenient and will save headaches down the road.

Tying It All Together

Now you know some of the most important plumbing codes for your next DIY project. Take this all with a grain of salt. We say that because you still need to check into local plumbing codes to make sure you don’t get yourself into any trouble.
If you want to talk to experts in local plumbing codes and have a professional plumber complete your project, give Autry Plumbing a call today!