To know whether it's time to replace your plumbing, you’ll need to closely inspect the plumbing or consult a licensed plumber. You'll want to be especially careful because of the expense: The project in a 1,500-square-foot home costs $2,000 to $15,000, depending on the complexity.
But you can mitigate the cost and hassle of replacing plumbing with these strategies.
Replace What’s Exposed
For a home with plaster walls, wood paneling, or other features that make it difficult to gain access to in-wall pipes, consider at least replacing plumbing pipes that aren’t buried in the walls.
Although it’s a big job, replacing plumbing pipes that are exposed in a basement, crawlspace, or utility room is fairly straightforward because your plumber can easily get at the pipes. Depending on your home's configuration, your plumber may be able to access the vast majority of your system this way.
For a 1,500-square-foot two-bathroom home, you’ll pay $1,000 to $6,000 to replace just the exposed plumbing.
Replace Plumbing When You Renovate
When you remodel part of your house and open up the walls and floors, make the most of the opportunity. Be sure to inspect — and if needed, replace — plumbing lines you've exposed. This includes the kitchen or bathroom you're remodeling and any pipes passing through the walls to feed upstairs bathrooms.
Because the project exposes pipes and your plumber is coming anyway, the added cost may be relatively reasonable. You may have to spend only $250 to $1,000 — a bargain, considering you’ve eliminated a hard-to-get-at problem area.
Consider Less-Expensive PEX
If you’re thinking of replacing plumbing that’s inside your walls, your plumber may be able to avoid demolishing the wall. The solution? A flexible plastic hose called cross-linked polyethylene tubing, or PEX.
PEX can be snaked into walls in much the way electricians feed wires behind the wallboard or plaster with relatively little surgery. That's not an option with rigid copper pipe. PEX meets building code nearly everywhere, comes with a five-year warranty, and costs less than copper. For comparison, 100 feet of PEX costs less than $30, but 100 feet of straight copper pipe costs about $285.
PEX also may may need less labor to install and therefore save more money. For example, a home that requires two days of labor to replumb would require only a day with PEX. Still, some environmental groups worry about as-yet-unknown health risks of plastic water supply lines.
Since PEX has been widely used in the U.S. for only about a decade, its track record is too short to show how long the plumbing will last. So, you won't know how long it will take before you need to replace the plumbing again.