How to reroute pipes laid in a concrete slab
Know where plumbing can be routed through slab foundations before attempting.
When my house was built, the copper plumbing was laid in the concrete slab. How does one go about rerouting the pipes?
“When you’re replacing pipes buried in a slab, it’s generally easiest to reroute the pipes into walls or ceilings,” says Jack Cowell, owner of highly rated Jack's Plumbing & Repair in Ansonia, Conn.
He adds that the new piping can also be installed in closets or in dummy baseboard heating boxes. “PEX tubing [a flexible plumbing pipe product] can be helpful in reducing the labor cost on the project because it allows for greater flexibility and fewer connection fittings, which reduces the chances of leaks,” Conway says.
He advises that it’s important to pick the right PEX tubing product, as there are specific types made for heating lines and others for domestic water lines.
Although Cowell says that he commonly sees plumbing routed through slab foundations in Connecticut homes, Anthony Stevens, president of highly rated A & N Plumbing in Bronxville, N.Y., says that type of system is virtually nonexistent within New York City. “As far as my knowledge goes, you cannot route pipes through concrete slab in New York City,” he says. "That's not up to code."
Cowell says rerouting the pipes around the slab, rather than accessing it via cutting through the slab, is a much less expensive and messy alternative, as concrete-cutting work adds significant labor costs.
He adds that the newly rerouted PEX piping should last as long, if not longer than the original copper slab-laid pipes. “Once you’re relocated your piping and installed new, quality material, it should last just as long as the original piping,” he says.