3 Basement Plumbing Issues You’re Probably Overlooking

This article is by Vincent West. West is a graduate from the University of Minnesota with a degree in Engineering Design.

Even though we have made huge technological leaps in many areas, plumbing systems have not changed much over the last few centuries. Although not every home has a basement, those that do have one require special attention. For this purpose, we have compiled a small list of plumbing issues that every homeowner should attend to on a regular basis.

Basics of Basement Plumbing

Before addressing some of the most common plumbing issues in basements, let’s do a brief rundown of the basics of basement plumbing. The first thing every responsible homeowner should know is the location of the shutoff valve. Usually, the shutoff valve is located either where the main supply pipe enters the house, or next to the water meter.

Some properties may have an additional shutoff valve right outside the house hidden in a ‘’buffalo box’’ or meter box. The buffalo box can be found either at the edge of your property or buried in the ground between your fence and the street. You can pry, open the box, and turn off the water supply by hand or by using a long handle key.

This info is critical for those situations where you will need to shut down the plumbing infrastructure before a project. In some cases, if you do not shut off the water source before beginning an important repair project, you risk flooding the basement. The water could reach the foundation and compromise the whole structural integrity of your house. Furthermore, in the case of severe clogging, the drains might get overwhelmed by the sheer quantity of water. If you want some more information on this topic, check this for basement floor drain backing up when it rains. and the fastest solutions.

Now, let us talk about three basement plumbing issues that most homeowners tend to overlook.

  1. Proper Trap Installation
    Plumbing traps are vital to the well-being of all plumbing systems. There are several types of traps, but the most common ones are the short, U-shaped traps located under your sinks, shower, and drains. These elements, called ‘’drain traps’’, prevent sediment, hair strands, and other small objects like rings or earrings from flowing down the drain and clogging the pipes.

    A trap also acts as a barrier between your house’s plumbing infrastructure and the sewer system. By retaining a small amount of water at its lowest point, a trap keeps deadly sewer gases from escaping into your house. So, it is a good idea to add traps to your basement plumbing. Every fixture like toilets, sinks, showers, and washing machines – especially if the unit is in the basement – should have a stable trap connection.

    Traps may present another problem if the fixture is not used frequently. Over time, the water from the low point of a trap that is not used regularly can evaporate, allowing sewer gases to leak into your basement. To prevent this issue, simply let the water run down the drain from time to time or pour mineral oil to create a long-lasting seal that will fight off sewer gases.
  2. Drainage
    All houses have a set of drainpipes that service showers, sinks, and toilets. However, some properties, especially those that were built more than 50 years ago, have outdated drainage infrastructures. When installing a basement drainpipe, you will have to remove the floor on top of the main sewer line and dig a trench.

    Any drainpipe should be installed with a downward slope of one-quarter of an inch per foot. You will have no issues doing this as long as your main sewer line connection is located at a reasonable distance underneath the floor.

    However, if you want to save some money, there are better solutions. Alternatively, the cheaper option would be installing a sump pump. A sump pump is a separate pumping system that is used to remove water collected in a sump basin. These systems are ideal in basements where flooding is a common occurrence. So, if you are dealing with moisture and standing water in your basement, a sump pump might be just the thing you need.
  3. Ventilation
    Another commonly overlooked aspect of basement plumbing is proper ventilation. Most people are unaware that plumbing systems have intricate vent connections that keep sewer gases away and allow water to drain smoothly without the risk of creating a water vacuum. Therefore, all fixtures must be vented.

    Vent placement and arrangement is usually set by local and state plumbing codes. The distance between the fixture and the drain waste vent is called the ‘’soil stack’’. In case it is not accessible, some plumbing codes allow owners to add admittance valves to drains – which are basically unidirectional vents that keep water ventilated while trapping any sewer gases in the pipes.


Because the basement is very often rarely used, many homeowners do not bother checking if there are any issues there. However, when it comes to plumbing, keeping the piping infrastructure in good shape and doing regular checkups are less costly than repairing. Just follow our tips here, and you will significantly lower the risk of a plumbing disaster.

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