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Everything You Need To Know About a Plumbing Stack

Everything You Need To Know About a Plumbing Stack

If you asked most people what a plumbing stack is, chances are you would get a blank stare as a response. That is because the term is not familiar to most people, even though a plumbing stack is one of the most important parts of a home’s plumbing system. Here is everything you need to know about plumbing stacks and how they impact your home.

What Is a Plumbing Stack?

A plumbing stack is a large pipe that supports all of the smaller pipes and equipment that makes up a home’s plumbing system. The smaller pipes feed into the plumbing stack, which sends wastewater and noxious odors from waste and other sources away from the home. A properly working plumbing stack is crucial for keeping water flowing through the home and venting the plumbing system.

Also known as a plumbing vent or vent stack, a plumbing stack is generally envisioned as a long, vertical straight pipe spanning the entire height of a house that has all of the other pipes for the home branching off it. The plumbing stack regulates the air pressure in the plumbing system while moving waste to a municipal or private sewer system and releasing noxious fumes and dangerous gases from the roof to dissipate in the air. If the plumbing stack is not working properly, it can compromise the whole plumbing system.

Parts of a Plumbing Stack

A plumbing stack is composed of three main parts: the vent stack, the drain stack, and the soil stack. The vent stack comprises the upper portion of the plumbing stack, starting just above where the topmost drain begins to flow into the plumbing stack and rising through the roof to the vent. This area is never touched by drain water and is responsible for venting bad air out of the house and introducing fresh air into the plumbing system.

The drain stack extends from the area where the top drainpipe attaches to the plumbing stack to the area where the lowest fixture drains into the plumbing stack. The soil stack represents everything on the plumbing stack below the lowest fixture, including the plumbing stack’s connection to the sewer. Issues with any these parts can negatively affect the health and well-being of anyone in the home. If you believe that there may be a problem with the plumbing stack in your home, contact the plumbing pros at Crystal Blue Plumbing Heating & Air of Loomis, CA by phone or through our website for an inspection and evaluation of your plumbing system.

Materials Used to Make a Plumbing Stack

Most of the plumbing stacks in use today are made out of cast iron or PVC plastic. Cast iron is more common in older homes unless a new home builder specifically requests that the contractor installing the plumbing system use cast iron for their new build. Both types of plumbing stacks have their advantages and drawbacks, so let’s compare them.

Cast iron is a tried and true material in plumbing, being used for this undertaking for hundreds of years. The biggest benefits of cast iron are that it is durable, is long-lasting, is not easily damaged, and is very heat- and fire-resistant. The biggest drawbacks are that cast iron is more expensive than other plumbing options, the walls of the pipes are rough enough to reduce performance, and they can break if rusted or otherwise made brittle.

PVC pipes are used in most new plumbing systems due to the advantages they have over pipes made from other materials. PVC plastic is cheaper than metal and can be easily molded into a variety of shapes to fit every situation. PVC pipes are also considered to have superior performance due to their smooth walls. The biggest disadvantages of a PVC plumbing stack are that it won’t last as long as one made of cast iron and there is a risk that it could melt if a house fire breaks out.

Common Issues With Plumbing Stacks

One of the most common issues that occur with plumbing stacks is the pipe becoming blocked with debris. When this happens, the wastewater cannot flow through the pipes properly and can result in sewage and sewer gases flowing back into the home from the plumbing system. This can be extremely hazardous to your health and the health of your family.

If you suspect that your plumbing stack is blocked, it is important to call a professional plumber, like the ones that work for Crystal Blue Plumbing Heating & Air of Loomis, CA, for a comprehensive evaluation. They will use specialized equipment to see into the plumbing stack, determine what is causing the blockage, and formulate a plan for removing the blockage quickly and efficiently without causing damage to the plumbing system.

Another issue that can occur with a plumbing stack is a negative pressure buildup in the pipes. This typically happens when the airflow of the roof vent is disrupted by clogging from bird’s nests, dead animals, leaves, or other debris. When this occurs, the water from your home won’t flow into the sewer system without some serious intervention. Getting the plumbing stack working correctly again will require a proper cleanout by a well-trained professional plumber.

Broken collars are another issue commonly seen with plumbing stacks. These collars are strips of metal, generally aluminum, that are combined with a rubber seal to protect the base of the roof vent of the plumbing stack. When the collar is applied, it prevents air, water, and other things from accessing the opening where the vent comes through the roof. Unfortunately, these collars can become damaged from exposure to the elements and direct sunlight, reducing their effectiveness at sealing off the openings.


A plumbing stack is a very important part of the home that needs regular inspections and maintenance to continue operating at peak performance. If you haven’t have your plumbing inspected for a few years, now would be a good time to see if there are any issues with your plumbing stack before they become catastrophic failures. Residential plumbing stack repairs and replacements can be expensive, so it is best to catch any problems early to minimize damage and expense.

Repairing a plumbing stack can vary in cost and complexity because the expenses will be based on several different factors. The size of the plumbing stack and its accessibility are big influences on the overall cost as is the material that the plumbing stack is made from and the cost of the replacement parts.

At Crystal Blue Plumbing Heating & Air of Loomis, CA, we offer a wide variety of plumbing services to cover your home from top to bottom. From plumbing stack inspections to drain cleaning, you can count on us to get the job done as quickly and efficiently as possible. We also offer heating and cooling services, repair services, and water testing for Sacramento, CA and the surrounding area. For more information on how we can help you with your home maintenance needs, contact us today!