InstallationUpdated July 7, 2026
Many Marseilles homeowners want the convenience of a second bathroom, especially in homes that see growing families or frequent guests. In older houses, space and plumbing can be the biggest hurdles. Adding a bathroom is more involved than just picking out tile and fixtures, it's a detailed process that runs right through the bones of your home. We've worked with homes dating back to the early 20th century, as well as newer builds, so we understand the range of challenges the local housing stock can present.
Finding Space and Choosing Layout
It starts with finding a suitable location. Some homeowners opt for a basement half-bath or convert a walk-in closet or unused corner. In Marseilles, basements are common, but the clay soil and moderately high water table can cause drainage issues, especially during wet months. You want to make sure the planned space has good access to existing water supply and drain lines to keep costs and complications down. A bathroom placed directly above or beside existing plumbing stacks minimizes the amount of new pipe runs.
Plumbing the New Bathroom
We always evaluate the main water supply line and drain line sizes. Many older homes in Marseilles have galvanized steel supply pipes, which may already be restricting water pressure or showing corrosion. Upgrading these pipes as part of a repiping project can prevent headaches and improve fixture performance. For drain lines, tying into an existing main waste stack is usually the most efficient approach, but the age and condition of cast iron or clay drain pipes must be checked for cracks or root intrusions, which are common in this area.
- Verify adequate water pressure for new fixtures
- Plan for proper venting to prevent sewer gas and slow drains
- Add a P-trap for every new sink, shower, or tub
- Slopes on new drain lines need to meet code to avoid backups
- Check for existing leaks before tying into old pipes
Drains, Sewer Lines, and Venting
On many jobs, we find that old cast iron or clay drain lines need inspection or replacement. Tying the new bathroom drain into a main cast iron stack can require special fittings, and sometimes hydro jetting is needed to clear out years of buildup before connecting anything new. If the new bathroom will be below the main sewer line (like in a basement), an ejector pump may be needed to lift waste up to the correct height. We work with sewer line services to guarantee proper connections and long-term reliability.
Venting is not optional, every fixture needs air for smooth drainage and to block sewer odors. Running new vent pipes up through the roof is best, but sometimes tie-ins to existing vents are possible. Poor venting is a common reason for recurring clogs and slow drains, so we never cut corners here. For tough blockages, our drain cleaning crew can handle even stubborn problems before new pipes are added.
Basement Bathrooms and Sump Systems
In Marseilles, the combination of clay soil and the Illinois River means many basements are prone to moisture, especially during storms. If you're adding a bathroom below grade, we strongly recommend checking the sump pit, pump, and backup systems. If your sump pump is unreliable or missing a check valve, it's a good time to handle upgrades so the new bath stays dry. We offer sump pump services and can evaluate your system during the remodel.
Water Heating and Fixture Choices
New bathrooms add to your home's hot water demand. Older water heaters may not keep up, especially if you add a tub or multi-head shower. Our water heater services cover upgrades, tankless options, and safety checks for expansion tanks and pressure relief valves. Choosing efficient fixtures, low-flow toilets, good quality shutoffs, updated faucets, helps reduce future repairs and keeps your water bill under control. Our team has handled faucet and fixture installations in homes of all ages, so we know what lasts.
Steps for a Successful Second Bathroom Addition
- Work with a plumber to map out pipe and vent routes before demolition
- Inspect existing supply and drain lines for corrosion or damage
- Plan for proper fixture venting and access to cleanouts
- Test sump systems and address moisture issues in basements
- Upgrade water heater or expansion tank if needed
- Use quality shutoff valves and flexible supply connectors for easy future repairs
Building codes and permit requirements vary, but LaSalle County and Marseilles follow Illinois standards for plumbing. An experienced plumber handles these details, from rough-in to fixture installation, and coordinates with inspectors to keep your project legal and safe.
If you want a professional, code-compliant second bathroom installation in your Marseilles home, our team is ready to help. Call us at 779-382-2518 to talk through options and schedule a site visit.