A burst line. A corroded joint. A pipe that’s been weeping behind a wall long enough to stain the plaster. In an older San Francisco home this rarely waits. Send a few details and one vetted, licensed San Francisco plumber gives you a straight read, not five companies fighting over your phone number.
Tell us what you’re seeing (a wet spot, low pressure, a stain, an actual drip) and roughly where. That points to whether it’s a spot repair or a sign the whole run is due.
Pipe repair here is shaped by the age of the housing. A lot of San Francisco still runs on galvanized steel supply lines and cast-iron drains put in before the war, with copper added in later decades. Each fails its own way. Knowing which material you have tells you most of what happens next.
| What’s in the wall | How it fails | Usually means |
|---|---|---|
| Galvanized steel supply (pre-1950s) | Rusts closed from the inside | Low pressure, rusty water – often replace the run |
| Cast-iron drain | Corrodes, cracks, bellies | Spot repair if isolated, replace if the run is gone |
| Copper (mid-century on) | Pinhole leaks | Soft Hetch Hetchy water is mildly aggressive; spot fix, watch the rest |
| Cast iron under a raised foundation | Rot at the joints | Reachable from below, often a cleaner fix |
Galvanized rusts shut, and that is the low-pressure, brown-water complaint. Cast iron corrodes and cracks. Even copper develops pinholes, because the city’s soft Hetch Hetchy water (2 to 3 grains per gallon) is gently aggressive to it over the years. Add a damp, foggy climate that keeps nothing dry, and a small leak quietly gets worse behind a finished wall. So the first real question is simple. One bad spot, or a tired run?
Spot repair or a tired run
An isolated failure is a clean spot repair. A cracked fitting, a nail driven through a line during a remodel, one corroded joint. But when a plumber opens up galvanized that has rusted to a pinhole, the honest question is whether fixing one spot just moves the next leak a few feet down the same dying pipe.
On a run that’s corroded end to end, patching it repeatedly costs more than replacing the section, and you live through the leak each time. The right answer is to see the pipe’s condition and get the straight tradeoff, not a repair that won’t hold or a full repipe you don’t yet need.
Why the access, not the pipe, often sets the price
Half the work in a San Francisco pipe repair is reaching the pipe. Lines run through narrow chases, under the floor in a raised foundation, or inside plaster in a flat with a neighbor’s unit on the far side of that wall. The bad section might be a two-hour fix once you’re on it. Getting to it cleanly, through the fewest and smallest openings, is where the skill and most of the cost live. On a supply leak the plumber isolates the right line before anything gets cut. On a hidden leak, precise location work keeps the opening small. On a failed drain, the fix has to restore proper slope, not just stop the drip. The goal is a repair that holds and a wall that closes back up cleanly.
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San Francisco pipe repair questions
Why is my pressure dropping in an older home?
In a lot of pre-war San Francisco homes it’s galvanized steel supply pipe rusting closed from the inside. The opening narrows over decades until flow drops and the water can run rusty. A plumber confirms it and tells you whether a section repair or replacing the run makes more sense.
Repair the leak, or repipe?
Often a spot repair is plenty: a cracked fitting or a single joint. The catch is when the leak sits in a run that’s corroded the whole length, because fixing one spot just pushes the next leak down the line. You’ll get shown the pipe’s actual condition and given the honest call, not a default upsell.
Do you have to open the whole wall?
Usually not. With the leak located, the repair opens the smallest access that reaches the bad section. In a flat or a raised-foundation home, that’s often from below.
Send your San Francisco pipe repair details
Tell us the symptom and roughly where. You’ll get an honest read on whether it’s a spot repair or a run that’s due to be replaced. No pressure to book.
No cost, no obligation. Just a clear answer from the one vetted, licensed San Francisco plumber who’d actually do the work.