When you're planning a major renovation—whether it's a full kitchen gut, a bathroom overhaul, or an entire home remodel—replacing old piping is one of those tasks that can make or break the project. Outdated plumbing isn’t just an inconvenience; it can lead to low water pressure, corrosion, leaks, and even health hazards like lead contamination. Getting the timing right for repiping keeps your renovation on schedule, prevents costly change orders, and ensures your new system meets modern safety codes. Below is an expanded, week-by-week timeline that covers every critical stage—from initial inspections to final sign‑offs—so you can coordinate your contractor, plumber, and other trades without last‑minute surprises.

Pre‑Planning Phase (Weeks 1‑2)

The pre‑planning phase sets the foundation for everything that follows. Rushing through this step is the fastest way to encounter budget overruns or code violations later on.

Hire a Licensed Plumber for a Thorough Inspection

Before ordering a single fitting, bring in a qualified plumber to assess the existing system. They will inspect visible pipes in the basement, crawlspace, or attic, and may use a camera to check inside drains. They’ll identify material types—galvanized steel, copper, polybutylene, or lead—and note any corrosion, pinhole leaks, or improper supports. This inspection gives you a clear picture of what needs to go and what can stay, saving labor and material costs.

Obtain Necessary Permits

Most jurisdictions require a plumbing permit for repiping work. Your plumber usually handles this, but you need to confirm that permits are obtained before demolition begins. Failing to pull permits can lead to stop‑work orders and fines that derail your entire schedule. Check with your local building department for specific requirements—many municipalities now require compliance with the International Plumbing Code (IPC) or the Uniform Plumbing Code (UPC).

Develop a Detailed Plan and Budget

Work with your plumber and general contractor to create a step‑by‑step plan. Map out where new pipes will run—through walls, ceilings, or floors—and decide how to route them around existing HVAC ducts and electrical wiring. Budget for materials (pipe, fittings, valves, hangers), permits, abatement if lead or asbestos is present, and a contingency of 10‑15% for unexpected issues like rot or termite damage discovered during demolition.

Design and Material Selection (Weeks 2‑3)

With the inspection complete, the next two weeks concentrate on choosing the right pipe materials and finalizing the system design. This phase often overlaps with the tail end of pre‑planning.

Compare Common Pipe Materials

Modern residential repiping typically involves one of three materials:

  • PEX (cross‑linked polyethylene) – Flexible, resistant to freezing cracks, easy to install with fewer fittings, and often more affordable. It’s become the go‑choice for many remodels, though some areas still require copper for exposed lines.
  • Type L or Type K copper – Durable, proven over decades, and naturally antimicrobial. Copper is more expensive and requires soldering, which can be tricky in tight spaces. It also has a high scrap value if you need to remove existing copper.
  • CPVC (chlorinated polyvinyl chloride) – Rigid plastic that’s less expensive than copper but more brittle than PEX. It’s less common today but still used in some regions for hot and cold water.

Your plumber will help you select based on local code, water chemistry, budget, and the demands of the renovation. If you have hard water or high chlorine levels, certain materials may degrade faster.

Plan the System Layout

Now is the time to decide on trunk‑and‑branch versus manifold (home‑run) systems. A manifold setup with PEX can simplify future maintenance and reduce pressure drops, but it uses more pipe. Coordinate with your contractor to decide whether to run new pipes in the ceiling to avoid cutting floor joists, or to use an exposed chase that can be boxed in with drywall.

Preparation and Logistics (Weeks 3‑4)

Once the plan is final and materials are selected, the focus shifts to procurement and site readiness. Proper preparation minimizes downtime during the critical removal and installation weeks.

Order All Required Materials

Your plumber should give you a comprehensive materials list. Order everything at once—pipe lengths in the right colors (red for hot, blue for cold is common with PEX), fittings, valves, hangers, and any specialty tools like crimp rings or expansion tools. Delays in receiving a specific fitting can stall the entire crew, so build in a few buffer days for shipping.

Clear the Renovation Area and Set Up Safety Measures

Remove all furniture, appliances, and personal items from areas that will be directly affected. Cover floors and remaining fixtures with heavy‑duty plastic. Set up warning tape around open trenches or holes. If your renovation involves opening walls, install dust barriers with zippered doorways to contain debris. This is also a good moment to set up a temporary water supply—many plumbers can run a garden hose from an exterior spigot or install a bypass valve so you still have some water during the repiping.

Notify Occupants and Coordinate Schedules

Let everyone in the household know about the upcoming work—including the likely noise, dust, and periods without water. Work with your contractor to align the plumber’s schedule with other trades. For example, electricians may need to run new wiring before the walls are closed, so a coordinated schedule avoids rework.

Removal of Old Piping (Week 5)

Demolition week is noisy, dusty, and often emotional as you watch old walls get opened up. But careful removal sets the stage for a clean installation.

Cutting into Walls and Floors

The plumber will strategically cut access holes in drywall or remove sections of flooring to expose the main water lines. They’ll use reciprocating saws with long blades to cut pipe cleanly, taking care not to damage adjacent wiring or structural members. If your home has a concrete slab, they may need a concrete saw for pipes running under the foundation—a messy job that requires extra time and containment.

Abatement for Hazardous Materials

Homes built before 1986 may have old solder joints containing lead, and some pre‑1980 structures used asbestos insulation around pipes. If tests confirm lead or asbestos, you’ll need a certified abatement contractor to handle removal safely. This adds time (often an extra 2‑3 days) and cost, but it’s non‑negotiable for health compliance. Check the EPA’s guidelines for lead‑safe renovation practices (see EPA Renovation, Repair and Painting Program for details).

Proper Disposal of Old Materials

Galvanized steel can be recycled as scrap metal; copper is highly recyclable and often brings some money back. Polybutylene should be disposed of as construction waste. Your plumber should coordinate with a scrap hauler or local recycling center. Keep a log of what’s removed for your records—future residents may need to know what type of pipes were replaced.

Installation of New Piping (Weeks 6‑7)

With the old pipes out and the area prepped, installation begins. This two‑week window includes the actual pipe installation, pressure testing, and any necessary adjustments.

Running New Pipe

The plumber will install hangers or straps to support the new lines according to code spacing (every 6 feet for horizontal runs, every 10 feet for vertical). For PEX, they’ll use a manifold in the mechanical room then run individual lines to each fixture, securing them with plastic clamps that allow for expansion. For copper, they’ll cut, deburr, flux, and solder joints—a slower process that requires fire‑safe practices. In either case, all branches to sinks, toilets, showers, and outdoor spigots are created.

Install Shut‑Off Valves and Rough‑Ins

Each fixture gets a dedicated shut‑off valve, typically a ¼‑turn ball valve for quick operation. The plumber will also install the rough‑in valves for tubs and showers, making sure they’re positioned at the correct height and setback per the fixture manufacturer’s instructions. This is the time to add any extra features like a whole‑house water filter or a pressure regulator if the incoming pressure is above 80 psi.

Pressure Testing and Leak Check

Once all connections are made, the system is pressurized with air (typically 50‑60 psi) and held for at least 15–30 minutes. A drop in pressure indicates a leak. The plumber will inspect every joint with a soap‑and‑water solution looking for bubbles. For copper systems, a hydrostatic test with water is common. This step is often witnessed by the building inspector if required by your permit. Fix any leaks before closing up the walls—otherwise, you’ll be cutting into fresh drywall later.

Wall Repair and Finish Work (Weeks 7‑8)

Once the pipes have passed inspection, the focus shifts from plumbing to finishing. This phase requires close coordination between your drywall contractor and the plumber.

Patch Access Holes and Open Walls

Drywall repair crews will fill the holes cut for pipe access. Use fire‑rated drywall if the holes are in garage walls or near a furnace. For larger openings, they’ll install backer boards and tape and mud seams. Allow adequate drying time between coats, especially in humid climates. If you’re also replacing flooring that was cut, schedule that work now as well.

Install Trim, Paint, and Fixtures

After the drywall is smooth and primed, you can paint walls and install baseboards. The plumber returns to set the finished fixtures: bathroom faucets, kitchen sink faucet, showerheads, and toilet connections. For a major renovation, this is also when the water heater is hooked up, if it was moved or replaced. Make sure all connections are snug and use plumber’s tape on threaded joints to prevent leaks.

Final Inspection and Approval (Week 8)

The final week involves a formal walk‑through with the building inspector and a complete system evaluation before you can start using the new plumbing.

Schedule a Final Inspection

Your plumber should request a final inspection from the local building department. The inspector will verify the work matches the approved plan, test all shut‑offs, check for cross‑connections, and confirm that backflow prevention devices (if required) are installed correctly. Common issues that fail inspection include missing pipe supports, unlabeled shut‑offs, and improper venting for drain lines if you replaced those too.

Obtain Certificate of Occupancy or Final Permit Sign‑Off

Once the inspector signs off, the permit is closed. Keep this paperwork for your home records—it’s often needed when selling the house to prove plumbing upgrades were done professionally and to code. If a certificate of occupancy is required (usually for larger additions), your contractor will handle that.

Post‑Project Follow‑Up and Maintenance

Your new piping system should provide decades of reliable service, but a little ongoing care will maximize its lifespan.

Schedule Regular Maintenance Checks

Every 12‑18 months, have a plumber inspect visible pipes for signs of corrosion, check pressure settings, and test shut‑off valves. If you have a whole‑house water filter, replace the cartridge as recommended. Keep an eye on your water bill—unexpected increases may indicate a hidden leak, even with new pipes.

Keep Comprehensive Records

Store photos of the piping before the walls were closed, along with diagrams showing where manifold connections and shut‑offs are located. This documentation is invaluable for future repairs, additions, or when you sell the home.

Educate Occupants

Explain the location of the main shut‑off valve and individual fixture valves. Advise against hanging heavy items on exposed PEX pipes, as they can kink. For copper, gentle use of water softeners can delay the onset of pitting corrosion if your water is aggressive. Simple habits—like not flushing non‑biodegradable items—protect the drain lines that were often updated alongside water pipes.

Replacing old piping during a major renovation is a significant investment in your home’s safety and value. By following this structured timeline—starting with careful planning and ending with proper documentation—you ensure that the pipes behind your walls will perform reliably for years to come. Coordinate with your plumbing contractor early, keep lines of communication open with other trades, and never skip the inspection step. Your future self (and your next home buyer) will appreciate the meticulous attention to detail.