PEX to Galvanized Pipe

[kellyj00]

I'm planning to replace some old galvenized pipes in my 45 year old home with more modern PEX. I plan to leave the lines leading up to each fixture from the crawlspace in galvanized, so I need to find a way to connect the old galvenized to the new PEX.

I don't have the ability to thread galanized pipe either, btw. If I have to remove any pipe to rethread it, I may as well just replace it with PEX.

Also, should I use anything bigger than 3/4" pex? The line to the street is 3/4 galvanized, according to a plumber and would cost $2000 to replace, so I'm waiting on that to see if replacing all the 3/4" galvenized to PEX will alleviate some of my flow problems. I have a 2 bathroom house, if that helps.

Jason Kelly Valley Center, KS

[Karl S]

Use an adapter. Male or female pipe thread on one end, PEX connector on the other.

[kellyj00]

So, I must grip the old pipe on one side of each joint and "dissassemble" rather than "cut away"?

Is there any solution to rusty connections? If it has rust, is it doomed to break as soon as I try to dissamble?

[Edwin Pawlowski]

No, won't be any benefit

It may, but since you are leaving some of the old pipe in place, it that is the culprit there is no change.

[kellyj00]

So, I have to replace all the pipe with PEX in order to do this right? Also, is $2000 to replace the main line (underground 36" in this region) a high estimate? Maybe I should shop around.

[Edwin Pawlowski]

If you have flow problems from a restriction, you have to replace the point that is restricted. It may be the line from the street, it may be the open lines you see feeding everything in the house, it may be right up to the fixtures. It may be a little bit of all of them.

If your house is 45 years old, it is probably galvanized from the street, maybe copper as it was used in the 1960's. Lead was often used in the 40's and early 50's. In any case, it may be near the end of its life. If may have a buildup on the inside, it may be corroding though and leaking even though you don't see any effects of the water yet.

If that is the case, nothing you do inside will help much. Is $2000 fair? Possibly. Has anyone on your street had their main replaced yet? If so, ask them. Often it means digging up the street, running a new line, then closing up and patching the street. It will be cheaper to do this before you have a break in the middle of winter though. If you see a few houses on the street having the water main replaced, it is a good time to set aside some money for yours.

I gave you a lot of "maybe" things. Only some testing can determine the real cause. If it is every fixture in the house, I'd start with the main. If it is only a particular bathroom, I'd start with the feed to that room.

[Eigenvector]

I'm slowly doing the same thing in my house. The toughest part will be to unscrew the old galvanized, but there's nothing for it. Get two big pipe wrenches and have at it. PEX is sold with transitions, they work well if you use pipe dope at the junction. One thing, as to flow, there are places that you can replace where the flow will dramatically improve - at vertical sections, at fixture outlets. The horizontal lines won't restrict you as much - surprisingly enough. So replace the sections near the input lines (sink supply, bath supply, etc.) and you'll see a huge benefit to the flow. Also, 1/2" PEX is more than adequate assuming a reasonable city supply.

One other thing to keep in mind, this is PEX, you don't run it in the traditional manner. Because it's so cheap it's just as practical and even better to run independent lines from the source to each fixture. So instead of a single line feeding 3 fixtures, run 3 lines.

[buffalobill]

how's the first hosecock or sink? good or bad? before digging, replace main shutoff and check pressure and flow: if good replace meter. if that's good, continue replacing all galvanized and inspect clogged elbows and pipes as you go.if all flow and pressure is poor, see what the neighbors have done and how they like theirs. you can't fix a lack of neighborhood street pressure, but you can increase flow like we did to a 1" copper main line. if arriving pressure and flow is still bad, bad, dig up and replace curbside shutoff and supply pipe to house. mine from street to curb to house at 4 feet down was $5000. once you have wonderful pressure and flow in the first basement fixture laundry washtub, you can begin looking for blockages and flushing existing pipes and bang on the galvanized elbows with a ballpeen hammer with destination fixture fully on and aerators removed.

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