Plumbing advice
Slab Leak: Repair Through the Floor or Reroute Overhead?
Both are real options and both are correct in different houses. Here is the reasoning a plumber uses, so you can follow the quote rather than just receive it.
Confirmed slab leak?
Ask for both prices in writing before deciding. A quote for only one of the two options is an incomplete quote.
- SPOT REPAIR
- One opening in the floor.
- REROUTE
- Line abandoned, walls opened.
- DECIDER
- Age of the rest of the copper.
The choice in one paragraph
A spot repair cuts the concrete at the located leak, repairs that section of pipe and repours the floor. A reroute leaves the failed line in the slab, abandons it, and runs a replacement through the attic and down inside walls to the same fixtures. Spot repair is cheaper today. Reroute is cheaper if the same line fails again.
Everything else is detail. What tips the decision is how old the pipe in the slab is, whether this is the first failure or the third, and what is on top of the floor you would be cutting.
Why south Cobb produces so many of these
Slab on grade construction dominated residential building across this area from about 1970 onward, and a large share of Austell, Mableton and Powder Springs housing dates from exactly that stretch. Copper supply lines were run in or under the concrete, and fifty years later they are reaching the end of a service life nobody was really planning for.
The failure is not dramatic. Copper sitting against concrete abrades fractionally with every heating and cooling cycle, and the Piedmont clay beneath flexes seasonally between a wet spring and a dry August. Small hot side pinholes are the result.
That matters for this decision because it means the failed pipe is rarely uniquely unlucky. It is the same age and in the same conditions as every other run under the same floor.
| Factor | Spot repair | Overhead reroute |
|---|---|---|
| Cost on the day. | Lower. | Higher, sometimes considerably. |
| What gets opened. | Floor, at one located point. | Attic access and wall sections. |
| Flooring you want to keep. | At risk, tile and hardwood are hard to match. | Untouched. |
| If the same line fails again. | You pay again, and open the floor again. | Nothing left in the slab to fail. |
| Future access for a plumber. | Still buried in concrete. | Reachable without a jackhammer. |
| Time on site. | Usually one day. | Often two or more. |
| Best suited to. | First failure, sound copper elsewhere. | Second failure, or valued flooring. |
The question to ask any plumber quoting a slab leak. Not just what the repair costs, but what the odds are of another failure on the same system in the next five years, and what a reroute would cost today. A plumber who will not discuss the second option is quoting a job rather than solving a problem.
How the age of the house pushes the decision
A first slab leak in a house built in 1985, with visible copper elsewhere in good condition, is a straightforward case for a spot repair. One failure is one failure, and paying for a full reroute against a hypothetical second one is spending money early for no clear benefit.
The picture changes completely by the third failure in four years. At that point the pipe under the concrete is not producing isolated accidents, it is telling you what the next decade looks like, and the arithmetic of repeated spot repairs stops working.
The middle case is the awkward one. A second failure, in a different room, three years after the first, in a house from the late 1970s. That is where the honest answer is genuinely arguable and where the reroute price deserves a serious look.
Signs that push toward rerouting rather than repairing
- This is the second or third slab leak in the same house.
- The floor above the leak is tile, hardwood or anything difficult to match.
- The house is from the 1970s and still on original copper throughout.
- There are already pressure or fixture problems suggesting wider system age.
- The failure is in a long run rather than close to an accessible edge.
- You intend to stay in the house for another decade or more.
What a reroute does not do
Rerouting a hot line abandons that one run. It does not replace the cold side, the yard line, or any other supply in the house, and it is not the same thing as a whole house repipe.
If the survey suggests the whole system is at the same stage, the honest comparison is between a full reroute of the hot supply and a staged repipe, which can be phased by zone. That conversation belongs on the table before you spend on either.
What you should have before you decide
Three things. A confirmed location marked on the floor rather than a guess, written prices for both approaches, and a clear statement of what the reinstatement includes.
That last one causes most of the disputes. A quote that includes cutting and repouring concrete but not replacing the tile above it is a different quote from one that includes both, and two numbers that look far apart are often quoting different jobs.
The tracing that produces the marked location is standard leak detection applied to concrete, and how the repair itself is carried out is set out on our slab leak page. If the pipe under the concrete is the same material as everything else in the house, the wider option is a staged repipe rather than either fix in isolation.
Both routes are permitted work. Inside the Austell city limits the permit comes from the city, in unincorporated south Cobb from Cobb County, and south of the county line from Douglas County. A slab repair carried out without one is a problem waiting at resale.
Quick answers
Questions people ask at this decision
Is a reroute a sign the plumber is upselling me?
Not by itself. On a first failure in an otherwise healthy system, a spot repair is usually the right call and a plumber recommending a reroute anyway should be able to explain why.
On a repeat failure, recommending another spot repair is arguably the less honest answer, because it postpones the decision at your expense.
Will rerouting affect my water pressure?
Not adversely when it is done properly. The replacement run is sized for the fixtures it serves, and in older houses a reroute occasionally improves pressure because it replaces a narrowed section.
Where pressure is already poor across the whole house, that is a separate diagnosis rather than something a reroute will fix incidentally.
Can I just shut off that line and live with it?
Sometimes, briefly, and only if the affected fixture group can be isolated without losing hot water to the whole house. It is a stopgap while you decide, not a solution.
Leaving a leaking line pressurised is the version to avoid, because saturated fill under one part of a slab behaves differently from the clay beside it.
Does insurance pay for either of these?
Policies commonly treat the resulting water damage differently from the failed pipe itself, and cover for breaking and repairing concrete varies a great deal between carriers.
Photograph everything before any cutting starts and keep an invoice that says plainly what failed and what was done. That helps with any claim, whichever route you choose.
Slab leak confirmed and unsure which way to go?
Call and ask for both prices. A trace, a marked location and two written numbers is what a decision like this should be based on.