Retro-Fitting PEX Manifold System, with Basement Apartment

[RyanOneill]

Hey Everyone, I have quite the project going on at my house right now. I'm currently replacing all the 45 year old copper lines since I completely demolished the basement apartment and it was out in the open. Every time I touched a pipe a joint leaked =(

I want to switch over to a home run system instead of the current trunk and branch. I do not like them. The plan is to rebuild the basement apartment and give it it's own hot water heater/manifold system. I will be supplying 2 bathrooms and 2 kitchens total. Small home.

My main water supply is only 1/2" but has 80psi. One day I will get it replaced to 3/4" but not today. Can't afford that bill with the rest of the renovations. For the time being, can I jump up to 3/4" after my main shutoff and supply the manifolds with that? I'm hoping there will be enough flow/pressure.

Also not sure how I should split the water supply between the main house and apartment. Should I run a T after the main shutoff and split into 2 manifolds, one for each unit, or supply the apartment from the main units cold water manifold?

Quite alot to read, I get that.. sorry =) . I've done alot of DIY plumbing stuff in the past, but thats mainly just replacing other people's work. Never had to think about proper supply distribution.

I really appreciate anyone who takes the time to read this and gives their input. Thank you so much!

 

[Geofd]

I did something similar...I split my house h/c 1stfl
h/c basement only had 1 kitchen/1 laundry it was a 3/4main and Iran
1/2 inch every were how many people In the house
how often are they home and using fixtures at the same time
it might be a little small for 2families

 

[TomFOhio]

I agree with Geofd. Until you replace your main line outside it might cut water pressure down when two families are running water at the same time but I think you already know that. I would run a main cold inside over to two separate manifolds and dedicate one for each apartment. That will keep the hot & cold separate between the apartments. I hope we helped you..

 

[RyanOneill]

Thanks guys.

Tom, that's what I was leaning towards, seemed like the most appropriate way to do it. Thankfully it's just me living in my house, with the basement apartment being just a 1 bedroom students rent. One day that main will be replaced, but I have quotes hitting upwards of $6,000 to dig it up and replace the 20ft line lol