How to Build a Bathroom & Toilet in Your Basement

Adding a bathroom to your basement living area can be a major convenience and can also allow you more options on what you use the basement area for. While installing a basement bathroom does present challenges, many can be lessened with proper planning and preparation.

Step 1

Select the best location for the bathroom. Pick not only the space which best fits your floor plan, but will allow the easiest and most efficient installation. Ideally this would be directly beneath a bathroom on the home's main level. This will allow you the easiest access to both water supply as well as a drain.

Step 2

Construct the framing using pressure-treated lumber. If building against an exterior wall, construct a frame against the wall which will allow you to enclose plumbing and electrical as well as hang your drywall. Place 2-by-4 studs on a maximum of 24-inch centers, although 16 inch centers are preferable.

Step 3

Plumb in your water supply and drain system. You will need a cold water supply line to your toilet and both hot and cold water to the sink. If installing a shower or tub, you will need to install both hot and cold water lines to this area as well. Tie in to an existing water supply line with a 'tee' joint. Install the drain line to the toilet area and run drain pipes from the sink and tub to the toilet area as well. You will have only one drain pipe extending up to the main drain pipe.

Step 4

Run all electrical wiring and install all electrical devices. All devices used in the bathroom must be GFCI (Ground Fault Circuit Interruption) devices. You will need at least one overhead light fixture, a outlet near the sink, and an outlet at the toilet. You can install additional outlets and light fixtures to accommodate your specific needs and desires.

Step 5

Hang the drywall using drywall screws. Install any full sheets first, then cut all other sheets to fit the remaining areas. Carefully measure and cut out for all electrical boxes and piping.

Step 6

Install appliances and connect all plumbing and drains. Install the shower/tub first to give yourself the maximum amount of room to maneuver the larger pieces. Then install the toilet and sink. The toilet will be equipped with a pump which will carry all waste water to the overhead drain. The better toilets have additional inlets for the sink and shower. This will allow you to have only one pumping system and a central drain. Connect all fresh water supply lines and install faucets and fixtures.

Step 7

Paint the drywall and install the floor covering to complete the project. You are also ready to install all electrical face plates, mirrors and light fixtures. Once these are all installed, your bathroom is ready for use.