Plumbing is one of the most perplexing topics for homeowners in the Boise, ID area, mostly because of the terminology. When you talk with an expert at Express Plumbing Heating & Air, we strive to explain your plumbing needs in terms that you can understand to help you make an informed decision. One topic that results in questions and confusion is that of wet vents. What are they, exactly, and why do you need them? Let’s talk a bit about how your plumbing works, and then we will cover the topic of wet vents.

Venting in Plumbing Systems

Venting of your plumbing is critical to keep the system running smoothly. In simple terms, venting ensures that water flows easily through the pipes by giving air an escape route. Without vent pipes, air gets trapped inside your pipes. You may notice unusual smells or bubbles coming from the bottom of your toilet. Dry and wet vents are the two main types of vents that are used for plumbing systems.

Dry Venting Versus Wet Venting

Dry venting is a pipe design in plumbing where there is a separate pipe for the air to escape. The water never flows through this pipe. Wet vents, on the other hand, manage air and water, but for different fixtures. Wet vents are most often used in bathrooms where you have limited space and high-capacity needs for the plumbing.

Benefits of a Wet Vent

Wet vents were first invented in 1920, and it is now part of standard building codes for plumbing systems. What distinguishes a wet vent from a dry vent is that it is used for both air venting and moving waste and water. Using your bathroom as an example, the sinks, toilet, shower, and tub all need to be vented. Without a vent, these fixtures would develop a range of problems. You may hear gurgling noises that are caused by air bubbles in the pipes. Methane gas may build up in the drain trap, and there may be an offensive odor. Other issues are slow drains and a toilet that empties slowly or requires multiple flushes to empty.

Wet Vents Are Cost-Effective

With a dry vent design, plumbers install extra pipes to manage the air inside your plumbing. This requires additional labor and materials. The plumbing pipes in wet vent systems are installed to handle both air and wastewater. As a result, a wet vent system requires less labor and materials.

Wet Vent Design

The experts at Express Plumbing Heating & Air most often recommend wet vents for bathrooms, but the design is effective in any room with multiple fixtures. In a bathroom, the wet vent is a single group of plumbing pipes that are attached to your sinks, toilet, shower, and bathtub. The pipes that are used for a wet vent are sized according to the load, and there is no maximum length of the wet vent. Not all the fixtures in your bathroom need to be attached to the wet vent. We may design your wet vent for only the toilet or sink, or we may recommend a wet vent for the walk-in shower and sink. Another common configuration for a wet vent is connecting the bathtub, toilet, and sink.

Plumbing Codes and Wet Vents

Because wet vents are relatively new additions to building codes, it’s important that you work with a plumbing contractor who is familiar with the design and requirements. All the fixtures on the wet vent must be on the same floor of your house. The toilet drain pipes must be lower than the drain pipes for the other fixtures, such as the sink and tub. If your wet vent is longer than four feet, the pipes must be supported with pipe brackets or braces. Some local building codes have a minimum length for a wet vent. All horizontal wet vents must be connected to drain pipes at a 45-degree angle. The correct pipe size must be used for the wet vent based on the maximum load of the fixtures.

What Is the Best Pipe Size for a Wet Vent?

Sizing pipes for a wet vent is another area where the professionals at Express Plumbing Heating & Air help homeowners in the Boise, ID, area. The pipes need to be of the correct diameter to handle the hydraulic pressure from the bathroom fixtures. In most cases, a 3-inch or 4-inch pipe is sufficient. Pipe sizing is based on the unit load that is determined by the frequency of use, rate of discharge, and time that the fixture operates. A 3-inch pipe can handle up to 12 unit loads, and this is adequate for most bathroom designs.

Disadvantages of Wet Vent Plumbing Designs

Even though wet vents save time and money during installation, they aren’t always the perfect solution. The design does have some disadvantages. You can only use a wet vent system for bathrooms that are on the same floor of your Boise, ID, home. If you have a guest bathroom on the first floor and the main bathroom on the upper story, you can’t use a single wet vent system for the two bathrooms. You have to install a separate wet vent system for each bathroom. Another disadvantage of a wet vent design is that the toilet has to be the lowest point. If it isn’t, you can expect some unusual smells emitting from the bowl. Installing wet vent systems requires compliance with strict rules and building codes. The experts at Express Plumbing Heating & Air are very familiar with these codes, but following them may mean that you have to rethink your new bathroom design.

Do Wet Vent Systems Clog More Often Than Dry Vents?

Many people believe that wet vent plumbing designs are more prone to clogs, but this isn’t true. There is one thing to keep in mind, though. Because all of your fixtures share the same plumbing pipes in a wet vent system, a clogged toilet may mean that you have no water for your sink or shower.

Are Wet Vents Effective in Multi-Story Homes?

From a technical standpoint, wet vents can be installed in a multi-story home, but a dry vent may be a better design. The most common issues with a wet vent in a multi-story home stem from the distance from the upper story bathroom to the drain pipes in the foundation. Remember, too, that a clog in the wet vent affects other fixtures in your second-story bathroom. If you install a wet vent on the upper floor of your home, you may experience clogs, odors, or slow drains and toilets.

Tips for Wet Vents

Wet vents are affordable, efficient plumbing designs that save money and time during installation. There are some tips to keep in mind. You should only work with a plumbing contractor who is experienced with wet vent systems. Make sure that building codes are followed, and have the work inspected during and after the job. You may need to be flexible with your bathroom design in order to satisfy building codes with a wet vent. We also recommend that you invest in high-quality materials, and avoid using materials that are damaged.

Professional Plumbing Services and Expert Advice

Express Plumbing Heating & Air offers expert plumbing services for homeowners in Boise, ID and the surrounding areas, including installation, repair, and maintenance. We are also happy to help with any questions you have about wet vents and other plumbing designs. In addition, we handle installation, repair, and maintenance of heating and cooling systems. Call us today to schedule an appointment with one of our professionals.

Brad Jordan

company icon