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 the configuration of your house, your plumber may be able to access the vast majority of your system this way.
For a 1,500 sq. ft., two-bathroom home, you’ll pay between $1,000 and $6,000 to replace just the exposed plumbing.
Replace plumbing when you renovate
When you remodel a portion of your house, take the opportunity to inspect—and if need be, replace—plumbing lines that you expose when you open up the walls and floors. This includes replacing plumbing in the kitchen or bathroom that you’re remaking, and any pipes passing through the walls to feed upstairs bathrooms.
Because the pipes are exposed during the project and because your plumber is coming on site anyway, the added cost of replacing plumbing may be only $250 to $1,000—a bargain, considering you’ve eliminated a hard-to-get-at problem area when you have the chance.
PEX limits demolition
If you’re thinking of replacing plumbing that’s inside your walls, your plumber may be able to limit wall demolition by using cross-linked polyethylene tubing, also known as PEX—a flexible plastic hose.
PEX can be snaked into walls in much the way electricians feed wires behind the wallboard or plaster with relatively minimal surgery—not an option with rigid copper pipe. PEX meets building code nearly everywhere, comes with a 25-year warranty, and puts a smaller hit on your budget than copper. For comparison, 100 feet of PEX costs less than $30. 100 feet of straight copper pipe costs about $285.
PEX also may offer lower costs in terms of labor. For example, a home that requires two days of labor to re-plumb will only require a day with PEX. Still, some environmental groups worry about as-yet-unknown health risks of plastic water supply lines.
And since PEX has only been widely used in the U.S. for about a decade, it doesn’t have enough of a track record to indicate how long it will last—in other words, how long it’ll be before replacing plumbing in your home is an issue again.