You do not need to open a wall to find out what is feeding your fixtures. A magnet, a coin, and five minutes in the basement or crawlspace will tell you almost everything, and in an older Seattle house, the answer is very often galvanized steel. Here is how to check it yourself, what each result means, and what to do once you know.
- What to bringA flashlight and a small magnet (a fridge magnet works)
- Where to lookBasement, crawlspace, or utility room, where pipe is exposed
- Fastest tellDull gray pipe with threaded, hexagonal joints is almost always galvanized
- What confirms itA magnet sticks; copper and PEX never do
Why it’s worth knowing before you call anyone
Knowing what you have changes the conversation. If a plumber recommends a repipe, you can check the pipe yourself first and get a rough sense of whether that’s likely. If you’re buying an older house, it tells you what to ask the inspector about. And if you already suspect rusty water or fading pressure is a galvanized problem, a two-minute check in the crawlspace confirms it or rules it out before anyone quotes you anything.
Where to look in a Seattle basement or crawlspace
Start where the water line enters the house, usually near the water meter or main shutoff, in a basement, utility room, or low crawlspace. Follow the largest pipe you can see; that’s the main supply line, and it usually reveals the material fastest since it’s rarely painted or wrapped. Check the vertical runs near the water heater and under sinks too, where a previous owner may have swapped in copper or PEX while leaving the rest original. Older homes rarely have one material throughout, so check more than one spot before you decide.
Four tests you can run yourself
1. The magnet test
Hold a magnet against a bare section of pipe. Galvanized steel and cast iron are magnetic, so the magnet sticks. Copper, brass, and PEX are not magnetic; the magnet falls right off. This is the single most reliable test and takes about ten seconds.
2. The color and finish check
Galvanized pipe is a dull, silvery gray, sometimes with white or orange crusting at the joints. Copper is a warm pinkish-orange, or a dull brown if it has weathered. PEX is flexible colored plastic, usually red, blue, or white. Cast iron is dark, heavy, and matte black.
3. The threaded-fitting check
Look closely at where two pipe sections meet. Galvanized pipe is joined with threaded, screwed fittings, and you’ll usually see a distinct hexagonal shape where one section threads into the next, sometimes with dried joint compound at the seam. Copper is joined with smooth soldered fittings, and PEX uses crimp or push-fit connectors with no threads at all.
4. The scratch test
If you’re still not sure, a light scratch with a key or a knife edge on a spot you don’t mind marking tells you fast: bright, shiny gray metal under a dull zinc coating means galvanized steel. A pinkish, coppery color under the surface means copper.
What the water itself can tell you
Run the hot tap first thing in the morning, before anything else in the house runs. Galvanized pipe rusts from the inside, so standing water picks up a rust tint overnight. If it runs brown or orange for a few seconds and then clears, that’s a strong sign the supply line upstream is galvanized and already corroding. Clear water doesn’t rule galvanized out on its own, but discolored water almost always confirms it. For the fuller symptom list, see signs your old house needs repiping.
House-age clues by Seattle neighborhood
The year your house was likely built is a strong hint before you even find the pipe. Queen Anne‘s foursquares and Victorians mostly date to the 1900s through 1930s, squarely in galvanized territory. Ballard‘s bungalows and craftsman homes cluster in the 1910s through 1940s, the same story. Wallingford‘s craftsman stock runs mostly 1910s to 1920s. Fremont mixes early-1900s cottages with later infill, so material can vary block to block. Magnolia leans a bit newer, with more 1940s through 1960s mid-century homes, so more of that stock has original copper or a copper-and-galvanized mix. None of this replaces looking at the actual pipe, but it tells you what to expect before you climb into the crawlspace.
Pipe materials by era, at a glance
| Typical era | Common supply pipe | What it looks like | Magnetic? |
|---|---|---|---|
| Pre-1960 | Galvanized steel | Dull gray, threaded hex fittings, often crusted at joints | Yes |
| 1960s–1970s | Copper becomes common | Pinkish-orange, soldered joints | No |
| 1970s–1990s | Copper, some CPVC | Copper as above; CPVC is rigid cream-colored plastic | No |
| 2000s–present | PEX common in new work and remodels | Flexible colored plastic (red/blue/white), crimp or push-fit joints | No |
- We confirm what you find with a camera and pressure check, not a guess
- Findings explained in plain language before any options are discussed
- Options priced and approved before any work begins
If your check points to galvanized, the next question is usually how much of the system is affected and what that means for cost. Our guide to what drives the cost of a whole-house repipe covers that, and if two quotes you’ve already gotten don’t match, why repipe quotes differ explains what to look for.
Found galvanized pipe? Let’s confirm it properly.
I’ll run a camera and pressure check on the actual system, explain what I find in plain language, and send you options to approve before anything starts.
Related pages
Whole-house repiping in Seattle
Mitigation vs. a full repipe, how the process works, and what the tiered quote covers.
Galvanized pipe replacement
Why galvanized fails from the inside, and how a replacement job actually runs.
Signs your old house needs repiping
Six symptoms homeowners actually notice, and when it isn’t the pipe at all.
Questions homeowners ask about identifying pipe
Is the magnet test really reliable?
Yes, for telling galvanized steel apart from copper or PEX. Steel is magnetic; copper, brass, and plastic pipe are not. The one exception is cast iron drain and sewer pipe, which is also magnetic, so make sure you’re testing a supply line and not a drain stack before you draw a conclusion.
My pipe is gray and threaded, but the magnet doesn’t stick. What is it?
That’s usually chrome-plated brass, common on the short supply risers under sinks and toilets, not the main lines. Brass looks silver-gray like galvanized steel but isn’t magnetic. If the main line elsewhere in the house is magnetic, the house likely still has galvanized supply piping even if this one fixture riser is brass.
What if I find both galvanized and copper in the same house?
Very common in Seattle’s older housing stock, usually from a partial remodel decades ago. The galvanized sections are still the ones most likely to be corroding and worth a closer look. A camera and pressure check tells you exactly which runs are affected instead of guessing from what’s visible.
I can’t get to any exposed pipe. What else can I check?
Run the hot tap first thing in the morning and watch for a rust tint that clears after a few seconds. It’s not as certain as seeing and testing the actual pipe, but it’s a reasonable first clue when there’s no accessible basement or crawlspace, and it’s worth mentioning to us when you request a quote.
Does it matter which pipe material my house has for insurance?
Some insurers ask about supply line age and material when writing or renewing a policy, particularly for older galvanized systems. Requirements vary by carrier, so it’s worth a call to yours if this affects your decision. Either way, knowing what you have before that call puts you in a stronger position.
I confirmed galvanized pipe. What should I do next?
Start with should you repipe now or wait if there are no leaks yet, or request a free quote if you’re already seeing rusty water or fading pressure. We’ll confirm what you found with a camera and pressure check and lay out real options before anything starts.