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 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 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 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.
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 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 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.
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 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 covers patch scope, and the water shutoff guide 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 shows how each driver moves a quote, and the Dallas repiping cost guide 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 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 covers the full decision. And before you compare two partial quotes, the guide to repiping quotes and warranties shows what each should list about the pipe that stays.
