What are the Best Tips for Installing Basement Bathroom Plumbing?

T. L. Childree

Installing basement bathroom plumbing can be very challenging, but there are several tips that may be helpful. The most important tip is to plan carefully before beginning construction. An up-flush toilet is usually an appropriate choice for below grade installations; bathtub and sink drains can also be connected to some models. Try to locate the basement bathroom plumbing directly beneath an upstairs bath for easier connections to water lines and sewer drains. Remember to install additional wiring for the toilet, support the new water supply lines, and check all connections before closing up the walls.

For easier connections to water lines and sewers, basement bathroom plumbing should be located directly beneath an upstairs bathroom.
For easier connections to water lines and sewers, basement bathroom plumbing should be located directly beneath an upstairs bathroom.

Careful planning is important when installing basement bathroom plumbing. It is a good idea to map out the size and location of existing water supply lines as well as the overall configuration of the sewer drainage system. The project will be much easier if the correct fittings and piping are close at hand. Decide beforehand the kinds of tools needed and have them ready when beginning the work. Keep a few temporary caps on hand to plug any drains that are left open during the plumbing work.

Basement bathroom plumbing typically requires some type of sewage ejection method to carry wastewater to the upstairs drain. An up-flush toilet is usually the best choice for this task. This type of toilet is specially designed for below grade use and provides its own holding tank and pump. Some up-flush toilet models also allow the sink and bathtub drains to be connected to the tank and pump. An additional electrical circuit will be needed to operate this type of toilet.

When installing basement bathroom plumbing, it is best to locate the new fixtures directly below an existing upstairs bath. This location usually eliminates the need for awkward or difficult pipe connections. Locating the basement bathroom plumbing near existing piping also reduces material costs and installation time. The close proximity to an existing sewer drain can cut down on the workload of the toilet’s pumping system as well. If this location is not available, plan ahead to make sure a functioning sewer connection can actually be made.

All new water supply piping must be properly protected and supported. Plastic pipes must be supported at 6 foot (1.8 m) intervals. Copper and galvanized piping must be supported every 8 feet (2.4 m). Avoid installing any piping near the surface of an interior wall to prevent damage from wallboard fasteners. Be sure to check all water supply and drainage connections before installing the wallboard.

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Discussion Comments


@Iluviaporos - Well, I think it does help if you do what the article suggests and install the basement plumbing below the original plumbing in the house.

Generally I think in an old house you just have no choice but to put up with noisy pipes and things.

Personally, I think the best solution to that and all future problems is to fit the room with the best products you can.

Long term problems with plumbing often come from people trying to cut corners, and with a basement fitting you might think it isn't so important. But, if anything it is more so, because it's a bit more complex to install the toilet fittings and all.

In fact, unless I really knew what I was doing, I would get an expert in to do the work. But, that's just me.


One thing that I think never gets given enough thought when it comes to plumbing in general, is the noise.

If you are making a small, separate living space in your basement, whoever lives down there is going to have to put up with a lot of noise already from clomping feet and so on. You should try to insulate your pipes to keep them from making even more noise.

I've lived in basement rooms where every pipe noise seems magnified, and have been told it goes both ways as well. It's just something to consider if you are installing some new pipes.

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