Pex retrofit Question

[BrianPlumBrian]

Hello All,

I am a DIY replacing polybut. plumbing throughout my 2-story house with PEX. I am doing it piece meal as I renovate the home. My next project is the upstairs bath which has two sinks, toilet and separate shower/bath. That is a total of 5 cold lines and 4 hot. Current setup has a 3/4 line going to the crawlspace directly below the wall containing the plumbing, then seperating out into 1/2 lines to go to the bathroom.

Rather than replacing 9 lines up 2 stories, can I run the 3/4 inch lines (1 hot, 1 cold) up to the bath and then into mini-manifolds? This would be easier for me (by myself) and would seem like a better set up for hot water (hot water at sink, only a short distance then to get hot water to the shower in the mornings).

Thanks guys/gals, I am still learning this plastic plumbing stuff - very different from the copper I am used to!

--Brian

[BrianPlumBrian]

Oh, almost forgot to ask. What is typically done with the main line coming into the house? Its polybutylene. Just convert it to PEX as soon as it comes into the crawlspace, or do most people dig it all the way back to the meter and replace?

Thanks again,

--Brian

[hj]

If you already are running a 3/4" to the bathroom area, it seems the individual lines would be shorter if you did it conventionally with tees at each fixture, rather than going to the work of installing a manifold and running everything back to it.

[nimrod]

it is perfectly acceptable to run a 3/4'' line up then brach out to each fixture , with pex you have to watch your loads as it cannot handle the wsfu that copper can . the advantage to running "home runs" from the basement to the second floor is the limited amount of joints that are concealed or if you would use a manibloc manifold with seperate shutoffs for each fixture in the basement is kinda nice but costs more moola than running a 3/4''line to the bath .hope that helps .

[BrianPlumBrian]

Thanks for the replies. The manifold I meant is just one of the metal boxes with multiple outlets, cheaper than the big manifolds with individual valves, they are not expensive.

I will run the 3/4 line up to the second floor then.

What about the incoming pipe into the crawlspace from the meter? It is 3/4 polybutylene. I am not worried if it should rupture (under the house), so I was going to leave it and tie it into the PEX prior to the pressure regulator.

I appreciate the great help,

--Brian

[Terry]

If you have a place to connect, sure,
You can always do the pipe from the meter to the crawlspace later.
And when you do, you can increase the size too.

The only time I've used a 3/4" line to a home was for a one bath.
And really most of the time, I used 1" anyway.
A one bath home doesn't stay one for very long, someone always adds a second bath.

[BrianPlumBrian]

Thanks for the info,

Have a great day!

--Brian