Can You Use Auto Admittance Valves in 2015 Plumbing Code?

If you’ve ever tackled a plumbing project—especially in a tight space like a kitchen island or basement bathroom—you’ve probably heard of auto admittance valves (AAVs). These clever devices eliminate the need for traditional roof vents, saving time and money. But here’s the real question: Can you use auto admittance valves in 2015 plumbing code? The answer isn’t as simple as “yes” or “no”—it depends on your location, installation details, and whether your local authority adopts specific sections of the code. Let’s break it down clearly, so you don’t risk failed inspections or costly rework.

What Is an Auto Admittance Valve (AAV)?

An auto admittance valve, also known as an air admittance valve or AAV, is a one-way mechanical vent that allows air into the drainage system when negative pressure occurs (e.g., during a flush or drain cycle) but seals shut to prevent sewer gases from escaping.

Unlike conventional vent stacks that extend through the roof, AAVs are installed under sinks, in walls, or inside cabinets, making them ideal for remodeling projects or areas where running a vent pipe is impractical.

Did You Know?
According to the International Association of Plumbing and Mechanical Officials (IAPMO), over 1.2 million AAVs are installed annually in the U.S.—mostly in residential retrofits.

Is the 2015 Plumbing Code the Same Everywhere?

No. While many U.S. states and municipalities adopt the International Plumbing Code (IPC), they often modify it. The 2015 IPC does permit AAVs—but only under strict conditions (more on that below). However, some jurisdictions—like parts of California, New York City, and Massachusetts—ban or severely restrict AAV use, even if the base code allows it.

📌 Key Takeaway:
The 2015 IPC is a model code. Your local building department has the final say. Always verify with your AHJ (Authority Having Jurisdiction) before installing an AAV.

What Does the 2015 IPC Say About AAVs?

Section 918 of the 2015 International Plumbing Code governs auto admittance valves. Here’s what it permits:

• AAVs may be used to vent individual fixtures (e.g., a sink or toilet).
• They must be installed at least 4 inches above the flood level rim of the fixture they serve.
• One AAV can serve multiple fixtures only if they’re on the same branch drain and within the valve’s rated capacity.
• AAVs cannot replace the main vent stack of the entire drainage system.
• They must be accessible for replacement (not sealed behind drywall without an access panel).
• Only certified AAVs (tested to ASSE 1050 or 1051 standards) are allowed.

🛠️ Pro Tip:
Look for the ASSE 1050 (for individual fixtures) or ASSE 1051 (for branch venting) label on the valve. Non-certified valves = automatic code violation.

States & Cities That Allow (or Ban) AAVs Under 2015 Code

🔗 For more on plumbing codes by state, see the International Code Council’s adoption map.

Pros and Cons of Using AAVs in 2015-Compliant Systems

✅ Advantages

• Saves money: No need to cut through roofs or run vent pipes through walls.
• Faster installation: Ideal for kitchen islands, powder rooms, or basement bathrooms.
• Reduces roof penetrations: Fewer leaks and maintenance issues.
• Code-compliant in most IPC-adopting areas.

❌ Disadvantages

• Mechanical failure risk: Unlike passive vent stacks, AAVs contain moving parts that can wear out (typical lifespan: 20–30 years).
• Not universally accepted: Banned in some major cities.
• Must be accessible: Hidden installations violate code.
• Can’t vent entire systems: Only supplemental—main stack vent still required.

Step-by-Step: Installing an AAV per 2015 IPC Guidelines

Follow these steps to stay compliant:

1. Confirm local approval – Call your building department.
2. Choose a certified AAV – Look for ASSE 1050 or 1051 certification.
3. Install above flood level – At least 4″ above the highest fixture’s flood rim (e.g., sink overflow).
4. Secure vertically – Mount upright per manufacturer instructions.
5. Ensure accessibility – Install in a cabinet with a removable panel or leave access door.
6. Test the system – Perform a smoke or peppermint test post-installation (required in many jurisdictions).

⚠️ Warning: Never install an AAV in a pressurized system, below the flood level, or in a confined space without airflow—it will fail prematurely.

Real-World Example: Successful AAV Use in a 2016 Kitchen Remodel

In Austin, Texas, a homeowner remodeled a kitchen with a center island. Running a traditional vent would’ve required tearing up the ceiling and compromising structural beams. The licensed plumber installed an ASSE 1050-certified AAV under the sink, 6″ above the flood rim, inside an accessible cabinet. The project passed inspection under the 2015 IPC, which Texas had adopted statewide.

“It saved us $1,800 and two days of labor,” said the contractor. “As long as you follow the code to the letter, AAVs are a game-changer.”

Frequently Asked Questions (FAQ)

Q1: Are auto admittance valves legal in all U.S. states under the 2015 plumbing code?

A: No. While the 2015 International Plumbing Code (IPC) permits AAVs under Section 918, individual states and cities can override this. For example, New York City and much of California prohibit them. Always check with your local building authority.

Q2: How long do auto admittance valves last?

A: Most certified AAVs last 20–30 years under normal conditions. However, exposure to extreme temperatures, humidity, or grease can shorten their lifespan. Replace if you notice sewer odors near the fixture.

Q3: Can I install an AAV myself, or do I need a plumber?

A: While DIY installation is possible, most jurisdictions require a licensed plumber to obtain a permit and pass inspection. Improper installation is a common cause of AAV failure and code violations.

Q4: Do AAVs eliminate the need for any roof vent?

A: No. AAVs are supplemental vents only. The main plumbing stack must still vent through the roof to protect the entire system. AAVs only serve individual fixtures or branch lines.

Q5: What happens if I install a non-certified AAV?

A: It’s an automatic code violation, even if it “works.” Inspectors check for ASSE certification. Non-certified valves may not seal properly, risking sewer gas leaks—a serious health hazard.

Q6: Are AAVs accepted in commercial buildings under the 2015 code?

A: Generally, no. The 2015 IPC restricts AAV use to residential and limited commercial applications (e.g., single restroom in a small office). Large commercial systems require full vent stacks.

Conclusion

So—can you use auto admittance valves in 2015 plumbing code? The short answer: Yes, in most places that adopted the IPC, but only if installed correctly and locally permitted. AAVs offer smart, cost-effective venting for sinks, toilets, and islands—when used within code limits.

Before you buy or install one, always confirm with your local building department, use only ASSE-certified valves, and ensure proper placement and accessibility. Done right, an AAV can save time, money, and headaches—without compromising safety or code compliance.

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