galvanized pipes - when to replace

17 Replies

I am starting to purchase SFR homes to buy and hold. The homes I'm getting tend to be older 1900-1950 and so have galvanized pipes. What rule of thumb do people tend to use for when to replace them? when something's leaking? or when the hot water flow is becoming too slow? or when it's convenient because you're doing other rehab anyway? and then do a little at a time or all at once? thanks

All of the above.

If I am doing a rehab and we have easy access to them, and it doesn't cause a major production, we swap them out, usually for PEX but sometimes PVC/CPVC. Other times, if they are in difficult areas and the flow is good and not badly discolored or washing sediment into the basins, we will only do the main trunk line but leave the subsidiary lines. Occasionally, we don't mess with them at all if they look relatively clean inside if we've had a valve or tee off. If we make a repair on anything we don't put any galvanized fittings back as a rule. 

Most of the time we find that replacing the main trunk lines, if nothing else, and upsizing those lines makes a major difference in any flow problems. On the other hand, if your main service line from the street to the house is galvanized, and badly corroded, hardly anything you do in the house will make any difference. 

I replace them proactively if they are accessible. If they are buried in walls like going to 2nd floor Bathroom, I'll leave them be.  
Go PEX. 

galvanized pipes get replaced before the first tenant moves in. no question.

Replacing galvanized pipes and going with PEX is something I always do. The galvanized will rust at the joints causing them to be weak and a likely spot to start leaking. I'm a big believer in doing as much as possible during the initial renovation to prevent future maintenance / service calls. Its a lot easier and cheaper to do the repair on your schedule with the house vacant as opposed to waiting until you get a call (always at an inconvenient time) or maybe worse... you don't get a call and the leak or issue goes unaddressed causing collateral damage.  

I wait until they stop functioning like they should. Could still get many years out of them with no problems.

As soon as I can.

Galvanized pipes rot from the inside out so usually by the time you spot a leak or problem, it becomes a big one.  Replace easily accessible lines asap,  buried stuff as needed or if doing major remodel. 

Originally posted by @Craig Dudley :

 I'm a big believer in doing as much as possible during the initial renovation to prevent future maintenance / service calls. Its a lot easier and cheaper to do the repair on your schedule with the house vacant 

Thanks Craig - I think that sounds like a sensible way to go. I appreciate the input!


More seriously never saw one that doesnt throw crap in the cartiges and wrecks them every few.  Plugs aerators etc.  

As said big size from incoming to water heater etc.  Every faudet gets its own run,,,and shutoff.  BUT dont oversize hot water to the bath shower  or the sink,,,again individual runs. 1/2 inch will handle all a faucet will flow.  Any larger and you have a huge waste and wait for water to get hot

Other thing is they have tons of support clips etc in the big box stores.  When you think you have enough double it,,,especially on long radius turns so it never kinks.  Easy to use,pop in and out as needed.  Those 1/4 turn bend supports are junky but works on 1/2 but 3/4 not so good.  Lots o clips and a middle support with long arms to joists work better.

AND while you have the cippy saw and hammer all warmed uo,,,change the metal drain pipe also.  Metal will plug and cause headaches 10X worse than white pvc plastic

@Peter Grote your first post is asking the question and answering it at the same time, as @JD Martin said "all of the above".  I recently purchased a duplex build in 1900, the property is occupied with inherited tenants, the house still has galvanized piping, my plan at this time is to budget for full replacement right away but as long as the current tenants stay I will not make any changes unless a problem occurs.  obviously if you are doing renovations to a kitchen or bath I would not leave those pipes in the wall, but at this point of you are not doing any work at this time you are not doing anything wrong by leaving it in place.


@JD Martin @Craig Dudley How do I know if I should also replace the main service line from the street to the house. It looks rusted right where it comes out of the ground in the crawl space but it hard to know how much corrosion inside - it's probably the original 100 yr old pipe, so I'm guessing replace as well?

Depends on how easy it is to access the pipe and how convenient it is to replace it now vs. wait until it's a problem. Most of the time, water moves through the main service line fast enough that water won't pick up much color, and the accumulation of rust flake is lower than in end-point spots - for example, a bathroom sink might only be used twice per day, so those galvanized pipes have water sitting dormant for a long time, whereas every time you use water you wash the pipe to some extent. That doesn't mean it's still not going to rust, it's just going to allow more of the particles to wash through the system, slowing down the closing of the pipe.

So if it were me, and the flow was great and the water wasn't discolored, and there was a tenant in there, I would leave it alone. If I was digging up the front yard to do new landscaping, I would replace it. If it were right next to a big tree, I would leave it alone. If the place was empty for a total rehab, I would replace it. If the yard was a big slope and the meter was 1,000 feet from the house, I would leave it alone. If the yard was a flat postage stamp, I would replace it. If I lived in Upper Michigan, I would leave it alone. If I lived in Florida, I would replace it. 

Most galvanized was actually put in from the 30's-late 60's. Before that you had a lot of lead service lines. 

@Peter Grote

Like Cassandra says replace them now or wait until a good freeze and replace them then.

@Peter Grote you can determine if the main service line is leaking by turning off the main water shut off valve inside the house and then going outside to look at the meter. If the meter is moving showing that water is running (and you're sure your shut off valve works) then you know you have a leak in the main line coming into the house.

If you have a leak in the main line then you need to replace it right away. If it's not leaking and you have adequate pressure then I'd leave it. If at some point in the future that changes, then you can replace it without disrupting a tenant too much.

The last house I renovated had that exact problem. I replaced the galvanized lines inside the house with PEX during the renovation. Then when I turned on the water at the street realized there was a leak in the main service line which was also galvanized. So I replaced that with PEX too. I got two quotes which were around $2,500-3,000. I ended up renting a mini excavator and doing it myself. Took me a day and all in cost of around $400. Biggest pain was that the line had to go under the driveway.

Here if it is galvanized from the curb stop into the house they try to "pull" a copper line in by pulling the galvanized out at the same time.  Saves alot of digging and disruption IF it works,,,if not it isnt any worse.  Dont think they allow underground pex here.

On replacing underground sewer pipe from house to the main its the place to examine same with a camera and determine from that if needed and how quickly.

Most metal drain pipes that are older are MOSTLY plugged long before they have symptoms.  They just rust out and plug from the inside so fast,,,maintaining them is a nightmare.

If you have copper pipe supply lines inside the house,,,your a theft target waiting to happen!!!

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