Do Macerating Toilets Need To Be Roof Vented?

Perhaps you’ve decided to add a beautiful en-suite bathroom to one of the bedrooms in your home. You have the color palette picked out and can envision the layout of what you want, but once you consult with your contractor, these hopes come to a grinding halt.

Unfortunately, the area where you want to add the bathroom is too far from the main supply line. Of course, you could add the bathroom with a major plumbing overhaul, but that would be astronomically expensive. So, now what?

After a bit of research, you come across macerating toilets. And just like that, you might’ve found a solution to the plumbing fixture hiccup in your bathroom plan! But what about the requirements? Do these toilets require roof vents? Let’s find out.

What Is A Macerating Toilet?

Macerating toilets are those featuring an upflush toilet system. In a regular toilet, there’s a drain pipe extending below the waste level. This means it can operate using gravity instead of using a pump mechanism or something similar.

However, with a macerating toilet, waste is pumped out of the unit via a pipe tied into the main drain line. After flushing, the toilet sends the waste to a unit behind the toilet. Generally, this unit is tucked in a large container behind the toilet or within the wall. Powerful blades pulverize the waste, creating a liquid. This makes it easier for the pump to escort the waste away from the toilet and to the main drain line.

Since these toilets rely on a pump to move waste through the plumbing system, they’re not ideal for busy households. The pump can easily become overwhelmed if it’s used constantly every day by more than a few people. Eventually, the pump may fail altogether, so it’s best to use these toilets in specific scenarios.

Where Are Macerating Toilets Used?

As mentioned, macerating toilets aren’t suitable for every scenario. Generally speaking, they’re best for low-traffic homes, where the toilet won’t be used constantly all day.

They’re often used when the bathroom is too far from the plumbing system’s main drain line. Since installing a standard toilet in these scenarios would require a massive plumbing overhaul, a macerating toilet is a common choice for these scenarios.

Macerating toilets are also common in several other settings, like a cabin or off-grid homestead, as well as basements and workshops located a good distance from the main plumbing drain line.

These toilets require varying pumps based on the distance to the main drain line. Generally, the toilet needs to be within 10 to 15 feet of vertical lift and between 100 to 150 feet of a horizontal run of the main drain line. Without a properly sized pump, the system might be unable to move waste effectively to the main drain line, causing issues throughout the entire setup.

What’s The Difference Between A Macerating Toilet And A Standard Toilet?

As mentioned, standard toilets use gravity to move waste, whereas macerating toilets use a pump. This is the primary difference between the two: gravity and a pump. In a traditional gravity-flush toilet, the system uses the force of gravity through the hole in the floor, where it enters the plumbing system.


There’s an electric macerator and pump tank in a macerating toilet system. The waste flushes out the back of the system, where it gets turned into a slurry. Once it’s liquified, the system pumps it through the plumbing to your main plumbing line.

Once it reaches the main plumbing line, it goes where the rest of your home’s waste goes – either to the sewer system or septic tank.

Do Macerating Toilets Need To Vent Through The Roof?

Whether you have a macerating toilet or a standard toilet, there’s a good chance you’ll need a vent of some sort. Of course, there are a few exceptions. For example, the SaniCOMPACT macerating toilet doesn’t need venting.

However, nearly every other toilet, including macerating toilets, needs to be vented. With macerating toilets, many manufacturers recommend tying the system into the main plumbing stack in your home. Generally, these vents extend through the roof, although there are a few exceptions.

If you add a macerating toilet to your home, you will need to vent it. Whether you vent it through the roof by tying it into the main stack or use an alternative method (as approved by the manufacturer and local plumbing code) is up to you.

Does A Toilet Have To Vent Through The Roof?

Roof vents for toilets are the most common way to vent the system. However, while they’re usually the go-to method for venting these systems, there are a few alternative ways to achieve the same result.

For example, you could run the vent through an exterior wall. If you decide to do this, you’ll need to ensure the vent runs higher than the highest window of the house. Sometimes, the plumbing code will require the vent to go at least 12 feet away from the wall.

However, venting through an exterior wall isn’t approved by all local building codes, so be sure to check with your local building authority to ensure it’s allowed in your zone.

Why Do Toilets Need A Vent Pipe?

Although a vent pipe might seem entirely unrelated to a plumbing system, it’s actually a vital piece of the puzzle. Without a vented system, waste may not move properly through the plumbing.

When the system has adequate airflow (via the vent pipe), sewer gas can escape, and air can enter the lines when someone flushes the toilet (or uses a drain). The toilet wouldn’t flush properly without an air vent, as the air needs somewhere to go.

On top of that, the vent helps keep the water level in the toilet bowl consistent. If there wasn’t water in the toilet bowl, sewer gases could leave the toilet and enter the bathroom via those empty pipes. So, when there’s a vent, the pressure allows the smelly air and waste to escape but prevents the water from escaping entirely (or rising too high).

If your toilet is poorly vented, you might notice various issues with the plumbing system. Since the system would be unable to transport wastewater and solid waste out of the plumbing effectively, you’d begin to notice several unwanted side effects. For example, you might notice backed-up toilets throughout your home, overflowing drains, and other undesirable plumbing issues.

Frequently Asked Questions (FAQs)

Do Macerating Toilets Smell?

A properly functioning macerating toilet with an effective vent shouldn’t smell bad. If the venting system is inefficient or there’s an issue with the toilet system, you might notice foul odors emanating from the toilet.

If that’s the case, it’s best to investigate the problem, as there’s likely an underlying cause.

Are Macerating Toilets Noisy?

Although the exact noise level varies based on the brand of macerating toilet, these toilets aren’t usually noisy. Generally, they’re no louder than a regular toilet flushing. So, they shouldn’t create any excessively loud noises as they’re relatively quiet.

There are some relatively new models with the near-silent operation if the standard models are too noisy for your liking.

Are Macerating Toilets Reliable?

Generally speaking, macerating toilets are about as reliable as standard toilets. They usually function correctly for approximately 10 to 15 years before components begin to fail and require replacement.

Older macerating toilets reaching the end of their lifespans are notorious for being unreliable and constantly breaking down. So, if yours is barely hanging in there, it might be time for a replacement. All in all, they’re about the same as a normal toilet in this aspect.

How Long Do Macerating Toilets Last?

On average, macerating toilets last approximately 10 to 15 years before components begin to fail. Some may not last quite as long, while others might last longer. It all comes down to the brand, quality, and upkeep of the toilet.

Can You Use An Air Admittance Valve For A Macerating Toilet?

You might’ve heard of air admittance valves, often referred to as cheater vents. While you might be tempted to use this handy device to vent your macerating toilet installation, it’s not a good idea. Since these vents are one-way devices, they’re not suitable for the vent system on a toilet.

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