Adding a Bathroom to Your Basement: Plumbing Challenges and Solutions

This basement renovation could have it all — a media room, a bar, a gym, a bedroom, a kitchenette, an office, and more. 

Whatever you have planned for your basement remodel, including a bathroom is often ideal. A basement bathroom adds valuable convenience for your family today and boosts future resale value. However, doing it right requires careful forethought and planning.

Key basement bathroom considerations include drainage, ventilation, building materials, and lighting. Your best bet is to work with a reliable design-build partner familiar with local building codes and regulations to ensure your basement bathroom is up to code and well-designed.  

Drainage for Your Basement Bathroom

Just because you see plumbing running through your basement does not mean it is set up for bathroom drainage. 

Usually, a basement requires an ejector pump for proper drainage. Installing a basement bathroom is not an easy DIY project. As professionals, we use the knowledge we have to make the best decisions possible. Sometimes, that means pivoting as new information emerges.

We recently installed a bathroom and planned to install an ejector pump, as we usually would. As we cut out a typical section of cement and dug down for an ejector pump, we discovered the sewer line. The house was connected to the public sewer, but there was no way to determine the location of the sewer pipe. Typically, they're linked from the front of the home. 

We then had to ensure that we could incorporate the drains for the shower, sink, and toilet and route the plumbing lines to their designated locations. Gather as much information about the site upfront so you can place the bathroom properly and minimize disruption of the slab. 

If you're in a septic system, an ejector pump is more than likely needed. With a septic system, your design-build partner will need to ensure the system can accommodate an additional bathroom sink, toilet, and shower if you plan to install a shower. 

Another element that needs to be considered by local building codes is the use of a macerator. A macerator grinds up waste and pumps it up to the drain. Many towns do not allow them for basement bathroom plans that include more than a sink and a toilet. If the municipality allows it, your building partner should plan to locate the macerator in a space that is not visible. In most cases, it’s better to embed the system into the floor and install an ejector pump that can handle larger waste loads. 

Another important consideration, especially with older New England homes, is the use of cast iron pipes. When these are found, they need to be replaced with PVC because they have likely corroded and are past their useful life.

Proper Ventilation of a Basement Bathroom

Basement bathrooms need good ventilation for air circulation and moisture management. We always recommend timer switches. Some new fans feature energy efficiency and moisture measurement, ensuring the system runs until the moisture is removed. 

One ventilation shortcut to avoid is uninsulated flex ductwork. You should avoid using uninsulated flex ducts because they deteriorate over time. Often, we see bathrooms where the vent was installed with flex ducts extending into the soffits of the roof. When we pull them out, they are covered in mold. With the humidity of a warm shower, condensation collects in the uninsulated flex pipe and has nowhere to go. 

To avoid this issue, insulated ductwork should be installed, along with Fantec systems, which pull the air through the ductwork and remove moisture from the space and out of the home. In some bathrooms, there may be a fan for the shower area and another for the toilet. In this case, you can exhaust both the toilet and shower from one location. 

Sometimes, there are also simple solutions that help with ventilation, like installing a window. Your design-build partner can help design the right combination of ventilation features for your situation.

Using The Right Materials for a Basement Bathroom

Many older homes in New England have plaster as the interior wall material. This wall material is not ideal for a bathroom, especially one situated in the basement. The perfect product to use is green board, as it is moisture-resistant and well-suited for use on bathroom walls. 

Choose tile or other flooring that stands up to moisture as well. Even the choice of paint is essential. We recommend Benjamin Moore Bath and Spa paint because it resists water and moisture damage. Your design-build partner should help you make informed choices about materials to prevent moisture in a basement remodel. 

An experienced design-build company will be up on the latest innovations. For instance, we use a  Schluter system. When you place this foam board material beneath tile flooring, walls, or a shower, it will provide a well-sealed barrier against moisture penetration. It stops cracking or shrinking in the grout. Nobody wants to stand on the cold tile, making this an excellent opportunity to install the heated floor system that  Schulter has developed. 

Lighting Design For a Basement Bathroom

Unfinished basements are generally designed with few windows for natural light. 

Ensure that lighting is appropriately designed for both the bathroom and the basement. Consider these lighting design options

• If space is limited, consider using a backlit mirror or an integrated LED mirror.
• Ceiling height is often an issue in basements, so use flush-mounted or recessed lighting wherever possible. 
• Consider a motion-sensor night light near the toilet for nighttime use.
• If ductwork is in the way, your design partner can use offset or adjustable lighting to direct light where it is most advantageous.

The Right Basement Bathroom Design Makes All the Difference

Installing a bathroom in a basement can go smoothly when you know the challenges upfront and work with a company familiar with New England basement bathroom design. 

To learn more about the basement remodeling process, please read our eBook, “The Expert Guide to Luxury Basement Remodeling for Discerning Homeowners” And if you are ready to speak about your project, please schedule a home renovation discovery session.