# Partial Repiping in Dallas

> Partial repiping in Dallas: one bathroom, the hot side or an abandoned slab branch, with every transition and retained run named in writing. Get an estimate.

URL: https://fullboredallasrepiping.com/partial-repiping/

We replace a named part of your hot and cold supply piping and leave the rest in service, with your estimate saying exactly where new pipe meets old and what stays.

Call (469) 846-9377

Last Updated: November 10, 2026

One boundary, in writing

Your estimate names the fixtures that get new pipe and the old pipe that stays

Still a permit

The City of Dallas treats even a one-bathroom repipe as permitted plumbing work

Maybe it is one bathroom: the shower that runs weak, the vanity with a leak under it twice in a year. Maybe it is a hot line under the slab that just let go. When the trouble sits in one part of the house, you do not always need the whole system replaced. For partial repiping, Dallas homes usually get a named section done, such as one bathroom, the hot side or one wing, with the rest left in service. [Fullbore Dallas Repiping](https://fullboredallasrepiping.com/) replaces water supply lines in Dallas homes, from a single bathroom branch to the whole house.

A partial job lives or dies on its boundary, so we spend most of the planning on where that line goes, what sits on the other side of it and how the two are joined. After a partial repipe the house still has old pipe, and some of it feeds the new section. Your estimate and closeout record will say so; neither should ever call the house repiped. The [whole-house repiping](https://fullboredallasrepiping.com/whole-house-repiping/) page covers the full version.

## What we check on the first visit

We start at the main shutoff and the water heater, even when the complaint is one shower, because new pipe can only carry what the old pipe upstream hands it. We read static pressure with nothing running, then compare flow at the nearest and farthest fixtures. Those readings show whether the restriction sits in the area you want replaced or somewhere between it and the meter.

Then we identify the pipe at every spot where a boundary could fall. Color is not proof: dull gray can be galvanized steel or polybutylene, and cream or tan plastic can be CPVC. Our [guide to identifying water pipe material](https://fullboredallasrepiping.com/guide/identify-water-pipe-material/) shows how each looks at a stub-out. We also ask about repairs so far, which often tell us more than any one leak. Three pinholes on one hot branch in two years is a different problem from three on unrelated lines.

## Where should the boundary go?

Many Dallas houses sit on a slab, and that shapes most partial jobs. Branches often run under or in the concrete and rise to each fixture, so we usually abandon those under-slab branches and run new ones through the attic, dropping down interior walls to the fixtures they serve. The old lines are cut and capped where they leave the slab. If a single under-slab line has failed, the narrower version is [slab leak rerouting](https://fullboredallasrepiping.com/slab-leak-rerouting/).

Four shapes cover most partial jobs. One bathroom during a remodel, with the walls already open. The hot side only, from the water heater out, since warm water narrows galvanized steel faster; the [hot water line replacement](https://fullboredallasrepiping.com/hot-water-line-replacement/) page covers that scope. One wing or end of a long ranch house fed by its own trunk. Or the stub-outs and valves under the sinks, where rusted steel nipples meet newer pipe in the wall.

### When a partial repipe is the wrong call

We will tell you if it is. A partial repipe is a poor bet when narrowed galvanized steel sits upstream of the new section, because the new pipe can only deliver what the old pipe gives it. It is also a poor bet when the pipe that stays is so brittle that each cut cracks the next joint, which happens with aged CPVC. Then the boundary keeps moving and the job grows anyway. Our [repair-or-repipe guide](https://fullboredallasrepiping.com/guide/repair-or-repipe/) walks through that decision.

## Every boundary is a joint

Each place new pipe meets old is a joint we name on your estimate. New PEX to sound copper takes a brass adapter listed for the PEX system. Copper meeting galvanized steel that stays needs a dielectric union or a brass nipple, because copper and steel in contact corrode the steel at the joint. PEX meeting CPVC uses a listed transition, and we cut the old CPVC back to clean, flexible pipe with the right tool, not a saw that can crack it.

Cutover is its own event. When the water goes off and comes back on, the old pipe on the other side of the boundary gets a pressure swing, and loose scale moves. We flush the new lines, clean the aerators and check the old joints nearest the boundary after the water is restored. Those joints are also the first place to look if a leak shows up months later.

Want to know where your boundary belongs?

Tell us which fixtures are affected, what pipe you can see and the repair history, and we will price a defined section.

Call (469) 846-9377

## Does a small job still need a permit?

Yes. The City of Dallas Building Inspection FAQ limits the permit exemption to stopping a leak, and replacing or rearranging supply piping falls outside it. The work follows the 2021 International Plumbing Code with Dallas amendments, and we submit the permit through DallasNow. Since June 1, 2026 the City has coordinated plumbing rough and final inspections: the new pipe is inspected with the walls open, then again at the end.

That order matters for your drywall. Covering pipe before the rough inspection can bring the City’s $200 unauthorized concealment fee for the trade, and a failed visit costs a $75 reinspection, so the wall stays open until the rough passes. The [Dallas repiping permit guide](https://fullboredallasrepiping.com/guide/repiping-permits-dallas/) covers what the inspector looks at.

## Will you have to open walls?

Less pipe does not always mean smaller holes. A short branch can cross a tiled shower wall, a kitchen backsplash or a cabinet back, while an attic route can reach a whole bathroom through two small cuts at the top plate and one at each fixture. Your estimate lists each expected opening and who closes it; drywall, texture, primer and paint are separate tasks, and tile or cabinet work may be another trade.

The water goes off for the cutover. For most partial jobs the rest of the house stays in service while we build the new section, as long as there is a valve at the boundary. Where there is none, adding one is often our first step. The [wall openings and drywall repair guide](https://fullboredallasrepiping.com/guide/wall-openings-and-drywall-repair/) covers patch scope, and the [water shutoff guide](https://fullboredallasrepiping.com/guide/repiping-water-shutoffs/) covers timing.

## How we price a partial repipe

We price each partial job after the first visit, because the boundary is different every time. The biggest pieces are the number of fixtures and branches inside the boundary, how far the new route runs from the attic to each fixture, and how many transitions the boundary creates. Access matters as much as pipe: a one-story house with attic room is a different job from a two-story house with a finished ceiling between floors.

The material, new valves at the boundary, any water heater connections, the permit and inspections, and the patch, texture and paint scope all move the number, and your written estimate lists each. The [repiping cost estimator](https://fullboredallasrepiping.com/tools/repiping-cost-estimator/) shows how each driver moves a quote, and the [Dallas repiping cost guide](https://fullboredallasrepiping.com/guide/repiping-cost-dallas/) explains how partial and whole-house quotes compare.

## Before you decide

If the leaks keep coming back on the same material, our [guide to recurring pinhole leaks](https://fullboredallasrepiping.com/guide/recurring-pinhole-leaks/) explains what that pattern can mean before we draw a boundary. If the trouble is spreading rather than staying put, the [Dallas home repiping guide](https://fullboredallasrepiping.com/guide/dallas-home-repiping-guide/) covers the full decision. And before you compare two partial quotes, the [guide to repiping quotes and warranties](https://fullboredallasrepiping.com/guide/repiping-quotes-and-warranties/) shows what each should list about the pipe that stays.

Talk to us about your house

Call (469) 846-9377

Standards this work follows

- 2021 International Plumbing Code with City of Dallas amendments
- ASTM F876/F877 PEX tubing and fittings, or ASTM B88 Type L/M copper
- Listed transition fittings and dielectric unions where dissimilar metals meet
- NSF/ANSI 61 and 372 for drinking-water components
- Manufacturer installation instructions for the tubing and fitting system
- DallasNow permit with rough and final inspection

## What's included

- A written boundary: the fixtures, rooms or branches that get new pipe
- A list of the retained piping, by material, that still feeds or serves the new section
- Listed transition fittings at each point where new pipe meets old
- Isolation valves at the boundary where the route allows
- Pressure test of the new section before walls close
- Flush, aerator cleaning and a leak check on nearby retained joints after cutover
- Permit, rough and final inspection coordination
- A written list of access openings and who closes them

## Three ways to fix a supply problem that is not everywhere

|  | Spot repair | Partial repipe | Whole-house repipe |
| --- | --- | --- | --- |
| What changes | One fitting or a short length of pipe | A named branch, room, floor or the hot side | Every hot and cold line from the main to each fixture |
| Old pipe left in service | Nearly all of it | Everything outside the boundary, named in the estimate | None of the interior distribution piping |
| Transitions to plan | Two, at the ends of the repair | One at every point where the boundary crosses old pipe | Usually only at the main and the water heater |
| Fits when | The failure is local and the pipe around it is sound | Trouble is concentrated in one area and upstream pipe can deliver | Leaks or restriction show up across the system |
| Permit in Dallas | Only a leak stop sits inside the City's exemption | Permitted work with rough and final inspection | Permitted work with rough and final inspection |

## Related resources

- Decision Guide [Should you repair or repipe a house with leaking pipes?](https://fullboredallasrepiping.com/guide/repair-or-repipe/)One leak is a repair. A pattern of leaks on the same pipe is a decision. Here's how to tell which one your Dallas house has, and what sits between the two.
- Learn [What causes recurring copper pinhole leaks?](https://fullboredallasrepiping.com/guide/recurring-pinhole-leaks/)A copper pinhole is the end of a slow process inside the pipe wall. When they keep coming, where and when they show up tells you more than any single leak.
- Learn [How to identify water pipe material in a Dallas house](https://fullboredallasrepiping.com/guide/identify-water-pipe-material/)A magnet, a flashlight and the printing on the pipe tell you more than color does. Here is where to look in your Dallas house and what each material looks like.
- Learn [Wall repair after repiping: where do the openings go and who patches them?](https://fullboredallasrepiping.com/guide/wall-openings-and-drywall-repair/)A repipe needs access openings, and your walls close only after the new piping is tested and inspected. Where the holes go, how big they are and who finishes them should all be settled on paper first.
- Learn [Do Dallas repiping permits apply to a repipe, and how do inspections work?](https://fullboredallasrepiping.com/guide/repiping-permits-dallas/)A repipe inside the City of Dallas is permitted plumbing work. Here's how the permit, the rough-in and final inspections and the fees fit around your job.
- Cost Guide [Repiping cost in Dallas: what sets the price of a repipe?](https://fullboredallasrepiping.com/guide/repiping-cost-dallas/)Our typical ranges for a whole-house repipe, why your house can land well above or below the house next door, and how to read two quotes side by side.

## How a Dallas repipe usually runs

1. First visit We count 14 fixture connections, trace the copper from the main shutoff in the garage, find the original lines running under the slab, check static pressure and the PRV, and look in the attic for headroom, insulation depth and a clear path from the garage to both bathrooms.
2. Written estimate Your estimate names PEX-A with expansion fittings, a home-run manifold beside the garage water heater, new quarter-turn stops, the old under-slab copper capped and left in place, the number and location of wall openings, and whether patch, texture and paint are included.
3. Permit Rearranging supply pipe is outside Dallas's limited exemption for stopping a leak, so the repipe is filed as permitted work through DallasNow before any pipe is cut. We keep the permit record with your estimate so you have both for your files.
4. Protection and openings Floors along the work path are covered, furniture is moved back from the wet walls, and small openings are cut behind the toilets, at each shower valve, under the sinks, at the washer box and at the kitchen sink wall.

## What this work looks like

New PEX branch lines in an open bathroom wall, crimped to a brass transition fitting on an older copper stub

Hot-side PEX run leaving a gas water heater in a garage through a short metal connector and a ball valve

Capped copper line abandoned at a slab penetration beside a new PEX line dropping from the attic

Handwritten labels on a ball valve and a transition fitting marking where new piping meets old

Not sure where the boundary should go?

Tell us which fixtures are affected, what pipe you can see and what has been repaired so far, and we will price a defined section.

Call (469) 846-9377

## Partial repiping questions

### Does a partial repipe in Dallas need a City permit if it is only one bathroom?

Yes. The City of Dallas lets a plumber stop a leak without a permit, but replacing or rearranging supply piping falls outside that exemption. A one-bathroom repipe is permitted plumbing work under the 2021 IPC with Dallas amendments. We pull the permit and schedule a rough inspection while the wall is open and a final once the water is back on.

### Can new PEX be joined to the old copper or galvanized pipe that stays?

Yes, with a transition fitting listed for both materials. PEX to copper uses a brass adapter. Copper to galvanized steel needs a dielectric union or brass nipple so the two metals do not corrode each other at the joint. We name each transition on your estimate and label it at the pipe, because it is the first place to check if a leak shows up later.

### Will a partial repipe fix low pressure at one shower?

Only if the restriction sits inside the section being replaced. If narrowed galvanized pipe, a failing pressure-reducing valve or a clogged cartridge sits upstream or in the fixture, new branch pipe changes nothing. We compare static pressure and flow at the nearest and farthest fixtures first, so the boundary goes where the problem actually is.

### Is it smart to replace just the hot side of the plumbing?

Sometimes. Warm water speeds corrosion in galvanized steel, so the hot side often narrows first, and hot copper lines can fail sooner than cold ones on a pumped loop. Replacing only the hot side makes sense when the cold side tests sound, and your estimate will say plainly that the cold lines are old pipe that stays.

### If I repipe one area now, can the rest of the house be done later?

Yes, and planning for it saves money over time. We can leave valved, capped tees where the next stage will connect and run new trunk lines through the attic with room for later branches. Each stage still needs its own permit and inspections, and each one means another shutoff and a few more openings.

## Related services

Whole-house repiping

We replace every hot and cold supply line from the main shutoff to each fixture, usually rerouted through the attic on slab houses, then tested and inspected before the walls close.

Slab leak rerouting

When a hot or cold supply line leaks under your slab, we abandon that line and run new pipe overhead through the attic and down interior walls instead of breaking the concrete.

Hot water line replacement

We replace the hot-side piping, and any recirculation return, from the water heater to your fixtures, and reconnect your existing heater rather than selling you a new one.