9 Common Plumbing Mistakes to Avoid During a Kitchen Remodel

A kitchen remodel in St. Charles should feel exciting, not stressful. Careful plumbing planning protects your new cabinets, flooring, and appliances from leaks and headaches. If you’re mapping out layout changes or new fixtures, loop in a pro early and keep the plumbing front and center.

During design, it helps to review appliance choices, sink configuration, and wall changes with a licensed team. When your plans are ready, partner with a trusted crew for kitchen remodeling so the rough-in work lines up with your finishes and schedule.

Incorrect Supply Line Sizing

Undersized or mismatched water lines can leave you with weak flow at the faucet and a sluggish refrigerator fill. Homes near the Historic District or older blocks off Kingshighway may still have mixed materials that choke pressure.

Watch for these warning signs during planning:

Water flow drops when another tap runs
Dishwasher cycles take longer than expected
Pulsing or whistling sounds when you shut a faucet

Right-sizing lines during rough-in helps your new fixtures perform as advertised and reduces stress on valves and cartridges.

Skipping Proper Venting

Good venting keeps drains quiet, fast, and odor-free. In a remodel, moving the sink, adding a prep sink, or relocating a dishwasher can leave vents undersized or in the wrong place.

Improper venting can leave sinks slow and smelly, even when everything looks new. Talk with your contractor about the best path for a vent stack or approved alternatives behind the new wall layout, especially if you’re opening ceilings or shifting islands.

Poor Shutoff Valve Placement or Relocation

Shutoffs should be easy to reach and clearly labeled. When a base cabinet gets deeper or a trash pull-out moves in, valves can end up trapped behind drawers, making emergencies harder to handle.

Plan valve height and location before cabinets arrive. A neat set of hot, cold, and dishwasher shutoffs inside the sink base saves time during service and reduces risk if a small drip shows up after move-in.

Misaligned Drain Height for the New Sink and Disposal

Switching from a shallow, two-bowl sink to a deep single can push the outlet below the wall connection. That mismatch leads to awkward fittings, noisy traps, and frequent clogs.

Confirm rough drain height with your sink specs and disposal model. A quick adjustment during rough-in beats tearing out a new backsplash later.

Reusing Tired or Corroded Pipes

It’s tempting to keep what “still works,” but old galvanized or brittle plastic can fail under the vibration of construction and the higher flow of modern fixtures. This is common in older St. Charles neighborhoods and some 1970s–1980s kitchens in nearby St. Peters and Cottleville.

Hidden corrosion often turns into surprise leaks once new fixtures go in. Have your contractor inspect visible runs and evaluate what should be replaced while the walls are open.

During winter freeze-thaw cycles along the Missouri River, small weaknesses in exterior-wall plumbing can turn into big problems. Ask your contractor to keep supply lines away from cold exterior cavities and to insulate vulnerable runs while the walls are open.

Forgetting Appliance Water Needs

Pot fillers, filtered taps, and smart fridges need dedicated lines and clearances. Skipping those early means cutting finished drywall later or living without the feature you wanted.

Make a simple checklist during design:

Refrigerator water and ice line path and shutoff
Dishwasher hot supply, drain, and air gap or approved high loop
Optional pot filler supply and height at the range

Confirm the specs for each appliance before rough-in begins to keep the schedule smooth.

Dishwasher and Disposal Cross-Connection Issues

Improperly routed drains can send dirty water back into the dishwasher or allow food waste to settle in the wrong place. That’s not just annoying; it can shorten the life of your appliances.

Work with a team that understands approved routing and fittings for your jurisdiction. If you’re unsure where to start, consult a local remodeling contractor who coordinates plumbing, cabinetry, and electrical as one plan.

Ignoring Water Hammer and High Pressure

Quick-closing valves on modern faucets and dishwashers can cause banging pipes. High municipal pressure or an aging pressure-reducing valve makes the problem worse.

Excessive water pressure can shorten the life of your new appliances. Ask your contractor to evaluate pressure and add appropriate protection while the walls are open so the system stays quiet.

Assuming Minor Kitchen Plumbing Mistakes Won’t Matter

Small misses compound. A quarter-inch here, a forgotten adapter there, and suddenly the sink, disposal, and dishwasher don’t align with your cabinet cutouts.

Before the drywall goes up, confirm these details with your installer:

Exact centerline, height, and depth for sink supplies and drain
Verified vent path and size for the final layout
Labeled, accessible shutoffs for every connected fixture

Catching these items early helps you avoid callbacks and keeps your move-in on schedule.

How Local Conditions Affect Your Kitchen Plumbing

Many homes near Lindenwood and New Town have a mix of older and newer plumbing. Seasonal swings and river humidity can stress pipes, seals, and valves.

Ready to protect your investment and enjoy a smooth remodel? Schedule a design-and-plumbing walk-through with St. Charles Kitchens and Baths today, or call us at 636-916-0333.