Bathroom Remodel Plumbing

The Plumbing Side of Your Bathroom Renovation

A bathroom remodel can be a simple fixture refresh or a full gut down to the studs. Either way, the plumbing decisions you make at the start are the ones that will either pay off for the next 30 years or haunt you in 5. Doro Plumbing works directly with homeowners and with general contractors on bathroom remodels across the Hartford and southeast Wisconsin area, handling everything from valve replacements during a tile job to full re-plumbs of master suites and basement bath additions.

What We Handle in a Bathroom Remodel

Demo phase

• Cap or remove existing supply and drain lines
• Disconnect old fixtures so demo can proceed safely
• Identify and assess existing piping (especially important in older homes with mixed materials)

Rough-in phase

• Re-locate or extend supply lines for new fixture layouts
• Install new drain, waste, and vent (DWV) configuration
• Set new tub or shower base
• Install new shower valve, including pressure-balanced or thermostatic per current code
• Rough-in for new toilet location, including correct flange height for finished floor
• Vanity supply rough-in
• Add a second sink, bidet rough, or other fixtures as designed

Finish phase

• Install all fixtures: toilet, vanity, faucets, shower trim, tub spout, supply lines, shutoffs
• Connect drain assemblies, traps, and air admittance valves where applicable
• Install shower doors hardware coordination
• Pressure test, leak check, and clean up

Common Issues in Older Bathrooms

Hartford and West Bend have a lot of housing stock from the 1920s through the 1970s, which means we run into the same handful of issues during remodels:

Galvanized supply lines – corroded, restricted flow, often crumbling at threads. We typically recommend replacing any galvanized that’s exposed during the remodel.

Cast iron drain lines – these can be in great shape or actively failing. We do a camera inspection of the main stack if there’s any doubt.

Lead supply lines from the meter – rare but not unheard of in pre-1950s homes. Wisconsin has been replacing service-side lead lines through municipal programs, but the homeowner side often hasn’t been addressed.

Insufficient venting – older bathrooms sometimes lack proper venting, leading to slow drains and trap-siphoning. A remodel is the right time to fix this.

Wrong toilet flange height – common when previous owners added new flooring without resetting the flange. Causes wax ring failures within a few years.

Improper sloping on drain runs – 1/4″ per foot is the rule. Anything less leads to slow drains and standing water issues.

We catch and address these during the rough-in phase, when they’re easy and cheap to fix. After the walls are closed up, the same fixes cost ten times as much.

Working With Your GC

If you’re working with a general contractor, we work directly with them on the schedule. We’re used to coordinating with framers, electricians, drywall, tile, flooring, and the rest of the trades. We pull our own permits for the plumbing work, communicate clearly about what’s needed when, and don’t show up when other trades are still in the way.

If you’re DIYing the project and just need a plumber for the rough-in and trim, we’re happy to come in for the plumbing portions only. Most homeowners can handle demo and finish prep, while the wet work (rough-in, valve install, fixture set, pressure tests) is best left to a licensed plumber.