Why You Should Repipe During Your Kitchen or Bathroom Renovation

The tile is picked. The cabinets are on order. The contractor has the kitchen down to studs, and there it is: a run of dull gray galvanized pipe, threaded at every joint, rust bleeding at the elbows. Somebody asks the question everyone in that room is thinking. Should we replace that while it is open?

Usually, yes. If your house still has galvanized steel, polybutylene, or older copper that has already leaked, the best time to replace the water supply lines is while the walls are already open for the remodel. You open fewer finished walls, you live through one mess instead of two, and you do not set new cabinets and tile over pipe that is near the end of its life.

If the pipes are newer and in good shape, you may only need the lines inside the remodel replaced. And if the house was already repiped under a permit, you may need nothing at all. The rest of this post is how to tell which of those you are.

The short version of the decision

There are three ways to handle the pipes during a kitchen or bathroom remodel. Each fits a different house.

• Full repipe during the remodel. Fits when the house is on galvanized or polybutylene, has had more than one leak, or has weak pressure at several fixtures. Does not fit when the house was repiped recently and the work was permitted.
• Replace only the lines in the remodeled room. Fits when the rest of the house is on copper or PEX in good condition. Does not fit when the room is fed by an old galvanized trunk line. New pipe connected to a rusted trunk still gets the trunk’s pressure and the trunk’s rust.
• Leave the pipes alone. Fits when you know what is in the walls and it is sound. Does not fit when “we think it was replaced at some point” is the best anyone can say.

A reader who stops here has the answer. The sections below explain why those lines exist, and what goes wrong when the plumbing gets left to the end.

Why the remodel is the cheap moment

A large share of the work in any whole-house repipe is getting to the pipe. The crew has to open drywall or plaster, protect the floors, run new lines through the framing, and then close everything back up. During a remodel, the kitchen or bathroom walls are already open. That part of the job is done before the plumber arrives.

The rest of the house still needs access points. But the rooms with the most plumbing, the kitchen and the bathrooms, are usually the hardest to reach once they are finished. Those are the rooms your remodel has just opened.

There is also the simple math of disruption. A remodel means dust, noise, strangers in the hallway and a kitchen you cannot use. A repipe a year later means most of that again. Doing them together means you pack the dishes once.

The tile problem

Here is the scenario that sends people back to the phone. The remodel finishes. The new shower is beautiful. Six months later, a pinhole opens in the old copper behind the new valve, or a galvanized fitting finally lets go inside the wall behind the new cabinets.

Now the fix runs through brand-new tile and brand-new cabinetry. The leak itself might be a small repair. Getting to it is not. Old pipe behind new finishes is the most expensive place in the house to have a leak, because everything you have to remove to reach it is the newest thing you own.

Find out what is behind the wall first

Before you decide, you need to know what kind of supply pipe the house has. You can often tell without opening anything. Look at the lines at the water heater, at the main shutoff, and under the sinks. Our guide on how to tell what kind of water pipes your home has walks through each type, including the magnet test for galvanized steel.

Once the remodel opens the walls, you get a better look than any homeowner normally does. Use it. Things worth noticing:

• Galvanized steel. Gray, threaded joints, a magnet sticks. It narrows from the inside as it rusts, so pressure drops and the water can come out brown after the line sits.
• Polybutylene. Gray flexible plastic, sometimes blue or black. It has a history of failing at the fittings.
• Older copper. Reddish-brown, green at the joints when it is aging. Look for green crust, wet stains on the framing, or old patch clamps. A house that has pinholed once tends to pinhole again.
• Mixed materials. A short run of copper or PEX spliced into galvanized means someone already repaired a failure. The rest of the system is the same age as the part that failed.

Older homes can also have lead in the plumbing. The EPA notes that in homes without lead service lines, the most common lead problem is brass or chrome-plated brass faucets and plumbing joined with lead solder. A remodel that replaces the faucets but keeps old soldered lines behind them leaves part of that in place. A repipe replaces it.

How a repipe fits into the remodel schedule

The order matters more than the timing. A repipe slots into the remodel during rough-in, after demolition and before the walls close. Here is the usual sequence when the two jobs are planned together:

• Demolition. Your general contractor opens the kitchen or bathroom. Old fixtures come out.
• Layout. The GC and the plumber agree on where the new sink, dishwasher, shower valve, toilet and any new fixtures will sit. Valve heights and fixture locations get set now, not after the cabinets arrive.
• Repipe rough-in. New supply lines run through the whole house, with stub-outs placed for the new layout in the remodeled rooms. Other rooms get small access openings where the pipe has to be reached.
• Pressure test and inspection. The new lines are tested under pressure. The building department inspects them with the walls still open.
• Close-up. In the remodeled rooms, the GC’s drywall and tile crews close the walls as part of the remodel. In the rest of the house, the access openings are patched.

The inspection step is the one that cannot move. An inspector cannot sign off on pipe that is already behind drywall. If anyone suggests closing walls first and sorting out the inspection later, stop and ask why. Our post on what happens to your walls during a repipe covers access, patching and that sequence in more detail.

Who patches what

This is where remodels and repipes get tangled, so settle it in writing before work starts.

• Inside the remodel. Your GC is already closing those walls with new drywall, backer board and tile. The plumber should not patch walls that are about to be tiled.
• Outside the remodel. Hallways, bedrooms and other baths get small access openings for the repipe. On our jobs those openings are patched and textured. Paint is left to you or your painter, because matching color is a painting decision.

Permits: one project, two scopes

A whole-house repipe is permitted work. On a whole-house water-supply repipe, we pull the permit. Your remodel will likely have its own permit through your GC. The two can run side by side, but someone has to make sure the inspections line up with the schedule, so walls are not closed before both scopes have been seen.

The Contractors State License Board puts this on its homeowner checklist: your contract should require the contractor to get any needed permits before the work starts, and it should say whether permit fees are included. That applies to the repipe contract and the remodel contract both. The same checklist tells you to check the contractor’s license status with the board before you sign. Ours is CSLB #1057926.

PEX or copper, decided now

If you are repiping during the remodel, you will choose the pipe material at the same time you are choosing faucets. We install two:

• Uponor PEX-A. Flexible tubing that bends around framing with fewer fittings. Comes with a 25-year parts and labor warranty.
• L-grade American copper. Rigid metal with a joint at every turn. Comes with a 30-year warranty. Copper costs more than PEX on the same house.

Both are code-approved and both work with any fixture you are likely to pick. The longer comparison is in PEX or copper for a Bay Area repipe.

What goes wrong when the plumbing is an afterthought

Most remodel plumbing problems are scheduling problems. The pipe was fine. The order was wrong.

• The repipe gets booked after the cabinets are set. Now the plumber is working around new boxes instead of open framing.
• Only the remodeled room is replanned. New copper or PEX in the kitchen, still fed by a closed-up galvanized trunk in the crawlspace. Pressure at the new faucet is no better than at the old one.
• Valve heights are guessed. The shower valve is roughed in before anyone confirmed the tile layout, and the trim ends up off-center on the finished wall.
• Walls close before inspection. A failed or missed inspection means reopening walls that were just finished.
• No one owns the tie-ins. The main shutoff and the water heater connections are outside the remodel. Make sure they are inside someone’s scope.

What to tell your general contractor

Most GCs have coordinated with a plumbing subcontractor or a repipe specialist before. Make it easy for them by raising it before demolition, not after. Bring these questions:

• What supply pipe did you find when you opened the walls, and where does it go?
• Where does the repipe fit in the schedule, and who is waiting on whom?
• Who sets the final fixture locations and valve heights, and when?
• How will the remodel inspection and the repipe inspection line up?
• Who patches the access openings outside the remodel area?
• Are the main shutoff and water heater connections in the repipe scope?

If the answers are clear and written down, the two jobs fit together cleanly. If nobody can answer the first question, start there.

Questions homeowners ask

I am only redoing one bathroom. Is a whole-house repipe overkill?

It depends on what feeds that bathroom. If the house is on galvanized, the new bathroom is still fed by the old pipe, and so is everything else. If the rest of the house is on sound copper or PEX, replacing just the lines in that room can make sense. Knowing your pipe type answers most of this.

Can we stay in the house during the repipe?

Usually, yes. Water is shut off while the crew works and turned back on before they leave for the day. During a remodel you may already be living without a kitchen, so the repipe adds less disruption than it would on its own.

Does doing it during a remodel change the price?

Easier access can reduce the work, but every house is different. The visit is what prices the job. You can get a rough starting point from our repipe cost calculator.

Next step

If your remodel is in planning or demolition has just started, have us look at the pipes before the walls close. We will tell you what you have, whether a full or partial repipe fits, and how it lines up with your GC’s schedule. Book online or call (408) 295-4309.