Upsizing pipe after it enters house?

[Soupy]

I have a 50's home and I'm going to attempt to change the old Galvanized pipe to Pex. I can't replace the pipe that comes up through my crawlspace so I'm going to leave that. It is 3/4 galvanized pipe going into a 1" shutoff valve then back to 3/4" galvanized. Is it OK to up size to 1" Pex since pex runs a little smaller I.D.? I want as much volume as possible going to my two outside faucets which will be replaced with Woodford 3/4" faucets at the same time. I need volume to run lawn sprinklers.

Any downfall from upsize just a hair? I'll still feed the sinks and what not with 1/2" coming off the 1" main line going to the hot water heater and the two faucets.

Thanks

 

[Soupy]

I'll mention that the two new faucets don't exist at the moment. This all started because I want to relocate the outside faucets which are currently 1/2" faucets and poorly located. I figured now would be the time to just swap out all the old pipe. The kitchen and bathrooms have been updated with copper. That will all stay and tie off the new main line running through the house.

 

[Mr_David]

Do it. Bigger is better. What kind of pressure do you have?
If you have low water pressure bigger is even better.

 

[frodo]

I agree with Mr David, run 1'' as your main line and use 3/4 to branch off to the fixtures
then reduce to 1/2'' at the stop valve on the fixture

In my opinion, all 1/2'' pex is good for is tying your ladder onto the truck.

 

[Soupy]

Thanks, just to clarify I'll still have about 35 ft of 3/4 " pipe coming from the meter that I can't change at this time. So the main line will be a combination of 3/4" galvanized to 1" pex. My goal here is to get every last bit of volume I can for the sprinklers.

 

[Diehard]

Totally agree with the up sizing comments above.
I can't believe they used galvanized steel water piping in a house in the 50's. I haven't been to 100's of houses here in Mass. but a pretty good number. My experience has been that some of the real old houses still had lead water mains coming into the house, and a lot of brass piping that was being replaced with copper in the very early 50's.
Have you professionals seen galvanized water piping used for water?

EDIT: Google says...
"Galvanized pipes and fittings were commonly installed in homes prior to 1950 (some sites say it was used until the 1960s). Over time, the galvanized steel pipes begin to rust or corrode from the inside out, resulting in reduced water pressure and restricted water flow."
It's a wonder that 60+/- year old galv steel piping still carries water under pressure.

 

[Soupy]

Totally agree with the up sizing comments above.
I can't believe they used galvanized steel water piping in a house in the 50's. I haven't been to 100's of houses here in Mass. but a pretty good number. My experience has been that some of the real old houses still had lead water mains coming into the house, and a lot of brass piping that was being replaced with copper in the very early 50's.
Have you professionals seen galvanized water piping used for water?

EDIT: Google says...
"Galvanized pipes and fittings were commonly installed in homes prior to 1950 (some sites say it was used until the 1960s). Over time, the galvanized steel pipes begin to rust or corrode from the inside out, resulting in reduced water pressure and restricted water flow."
It's a wonder that 60+/- year old galv steel piping still carries water under pressure.

The house was built in 1956. It appears to be a 3/4" plastic coming off the water meter under ground outside. I have no idea how for that plastic runs because all I can see it whats in the box under ground. Here is a picture of the mainline from the meter coming up from the dirt floor in my crawlspace. I dug around a couple feet from here and didn't see any other transition from this galvanized pipe.

 

[chiraldude]

In my opinion, all 1/2'' pex is good for is tying your ladder onto the truck.

Especially 1/2" pex crimp connectors give you more like 3/8" flow rates.
Upsizing pex is a good practice if you are going to use the crimp type fittings. Because these have to fit the inside diameter of the pex, they can produce noticeable pressure/flow reduction.
If you use the propex (Uponor type) fittings, 3/4 pex would be fine. Unfortunately the expansion tool costs $300-400.

 

[WyrTwister]

The house was built in 1956. It appears to be a 3/4" plastic coming off the water meter under ground outside. I have no idea how for that plastic runs because all I can see it whats in the box under ground. Here is a picture of the mainline from the meter coming up from the dirt floor in my crawlspace. I dug around a couple feet from here and didn't see any other transition from this galvanized pipe.

I may be wrong , but that looks like a copper flare fitting coming up out of the dirt ?

Wyr
God bless

 

[WyrTwister]

Especially 1/2" pex crimp connectors give you more like 3/8" flow rates.
Upsizing pex is a good practice if you are going to use the crimp type fittings. Because these have to fit the inside diameter of the pex, they can produce noticeable pressure/flow reduction.
If you use the propex (Uponor type) fittings, 3/4 pex would be fine. Unfortunately the expansion tool costs $300-400.

Our hpuse , built in the 50's , was plumed in 3/4" copper . We had to replace the water main , 1-1/2 - 2 years ago .

I used 1" white PEX and brass fittings ( w/ copper crimp rings ) . Since the 3/4 " fittings had an ID less than 3/4 "
' . And because I had to take a longer & more crooked path with the new PEX .

Wyr
God bless

 

[chiraldude]

Our hpuse , built in the 50's , was plumed in 3/4" copper . We had to replace the water main , 1-1/2 - 2 years ago .

I used 1" white PEX and brass fittings ( w/ copper crimp rings ) . Since the 3/4 " fittings had an ID less than 3/4 "
' . And because I had to take a longer & more crooked path with the new PEX .

Wyr
God bless

Too bad hardly any DIYer is aware (or cares?) about the smaller ID of PEX crimp fittings. ProPex should be the standard but the Depot, Lowes, Menards, etc. stock none of it.

 

[Soupy]

I may be wrong , but that looks like a copper flare fitting coming up out of the dirt ?

Wyr
God bless

You may be right, I'm not sure to be honest. I hope it's copper. I guess I'll take some sand paper too it and see.

 

[Soupy]

It's copper coming in. That is the part that will not be changed at this time. The Galvanized above ground will get 1" pex with 3/4" branching off. For hot water line I'll go 3/4".

 

[Soupy]

Our hpuse , built in the 50's , was plumed in 3/4" copper . We had to replace the water main , 1-1/2 - 2 years ago .

I used 1" white PEX and brass fittings ( w/ copper crimp rings ) . Since the 3/4 " fittings had an ID less than 3/4 "
' . And because I had to take a longer & more crooked path with the new PEX .

Wyr
God bless

Yes that is my thinking on going with 1". Although I will not be replacing it all the way back to the meter. At least not this year.,

 

[Mr_David]

I may be wrong , but that looks like a copper flare fitting coming up out of the dirt ?

Wyr
God bless

GOOD CALL!!

 

[Mr_David]

I heard at one time back in the 90's that they were still using galv pipe back in Texas somewhere.
The quality of what or the PH was not so destructive to the galv pipe so they continued to use it for many years.
Like most places, they to have probably converted to pex.