help Replumbing old house

[Reznu]

So bought this house about 5 years ago, huge fixer upper. always had problems with our water, specifically poor water pressure if ANY 2nd fixture is turned on. the way it is currently installed is a 3/4" copper main coming in, going to the water heater, it branches off before the water heater with a 3/4" x 1/2" copper Tee, the 1/2 copper tee then feeds every fixture in the house. for the hot water, it comes off the water heater about 10 ft with 3/4 copper and then reduces to a 1/2 tee and again feeds every fixture off the 1/2" copper line
I've finally gotten around to addressing the problem and with (minimal) experience drew this up as the "solution" to the severe loss of pressure with any more than 1 sink/shower running. (if something like the washer is running, the pressure is so poor the fridge will start dripping because there isn't enough to hold the valve closed)

TL;DR/my question- will my (sorry for poor childlike paint sketch) plan fix said problem, and is there any "flaw" or major violation in it?
all pex b, with crimp rings, female copper sweat to pex b fittings for each fixture

 

[breplum]

nice try but that drawing is way to different than normal drawing to follow.
bottom lines: you don't need 3/4" to feed individual fixtures.
Even in PEX, 1/2" feed is fine for even two low gpm fixtures, unless you have a fast fill roman tub filler sized for 3/4". Keep shower hot with single 1/2" feed off a 3/4" branch.
Add a dedicated return hot water line and a pump setup and insulate all hot lines, then strap.

 

[Reznu]

nice try but that drawing is way to different than normal drawing to follow.
bottom lines: you don't need 3/4" to feed individual fixtures.
Even in PEX, 1/2" feed is fine for even two low gpm fixtures, unless you have a fast fill roman tub filler sized for 3/4". Keep shower hot with single 1/2" feed off a 3/4" branch.
Add a dedicated return hot water line and a pump setup and insulate all hot lines, then strap.

Yeah, the drawing is more of a layout and explanation of what I'd be doing. It'd be from the perspective of the floor, looking up at the joists in basement. The reasoning of going with 3/4 pex for individual fixtures is because they're still going to be plumbed with 1/2 copper,and since 3/4 pex b is nearly same ID of 1/2 copper I saw no harm in it. And regarding the hot water, I have no issues with my hot water. Every fixture is less than 15 ft from the water heater. So no real need for a recirculating system. The entire reason for doing this is to fix the pressure loss when using 2 fixtures at the same time, so I'm asking if doing this will solve that issue, and if in the way I'm doing it is going to be safe,proper and not breaking any serious "rules"

It's going to be service line from street (3/4in galvanized)>main line entering house(3/4 copper)>15 ft after entering house(converts to 1in pex)>50ft of 1in pex branching off to 3/4pex,converting back to 1/2in copper for every fixture.

Would be roughly 2ft of 3/4 pex for each fixture off the main 1in pex line, and then about 5ft of 1/2 copper.

 

[Reznu]

Yeah, the drawing is more of a layout and explanation of what I'd be doing. It'd be from the perspective of the floor, looking up at the joists in basement. The reasoning of going with 3/4 pex for individual fixtures is because they're still going to be plumbed with 1/2 copper,and since 3/4 pex b is nearly same ID of 1/2 copper I saw no harm in it. And regarding the hot water, I have no issues with my hot water. Every fixture is less than 15 ft from the water heater. So no real need for a recirculating system. The entire reason for doing this is to fix the pressure loss when using 2 fixtures at the same time, so I'm asking if doing this will solve that issue, and if in the way I'm doing it is going to be safe,proper and not breaking any serious "rules"

It's going to be service line from street (3/4in galvanized)>main line entering house(3/4 copper)>15 ft after entering house(converts to 1in pex)>50ft of 1in pex branching off to 3/4pex,converting back to 1/2in copper for every fixture.

Would be roughly 2ft of 3/4 pex for each fixture off the main 1in pex line, and then about 5ft of 1/2 copper.

Here are pictures of the CURRENT plumbing. 3/4copper main to water heater with a tee off to 1/2copper and stays 1/2copper branching off to each fixture.

 

[Rossando]

As long as your main run throughout is sized higher like 3/4" or 1" then feeding a 1/2" drop to each fixture is fine.

 

[breplum]

What is your pressure? I'll bet your existing 3/4" galv. main is why you get pressure drop.
It would be best to replace that old **** sooner than later and your pressure drop issues likely solved in one stroke. Galv. pipe rusts and throws off rust particles and causes impaired flow, which then makes you think pressure drop but really is "flow drop".
If you don't remove the old galv., then put a WYE STRAINER on it before connecting the new stuff, that way you prevent rust particles from impairing the new work.
And, get rid of that galv. strap on plastic drain pipe. Use made-for plastic hangers every four ft. as required.

 

[Reznu]

What is your pressure? I'll bet your existing 3/4" galv. main is why you get pressure drop.
It would be best to replace that old **** sooner than later and your pressure drop issues likely solved in one stroke. Galv. pipe rusts and throws off rust particles and causes impaired flow, which then makes you think pressure drop but really is "flow drop".
If you don't remove the old galv., then put a WYE STRAINER on it before connecting the new stuff, that way you prevent rust particles from impairing the new work.
And, get rid of that galv. strap on plastic drain pipe. Use made-for plastic hangers every four ft. as required.

We get about 26 psi at the furthest spigot. If anything else is turned on it drops down around 11. The galvanized service line from the meter to the house is going to be replaced by the city "within the next 2 years" because the city side service line has lead fittings. Does the PEX going through joists count as a hanger? I was just assuming joists spaced 17 inches there'd be no need for hangers.

 

[Reznu]

As long as your main run throughout is sized higher like 3/4" or 1" then feeding a 1/2" drop to each fixture is fine.

So then with the pre-existing 1/2in copper feeding everything else that is also 1/2in itd make sense to have pressure loss when using multiple fixtures? Especially since these copper pipes are probably 40+ years old

 

[GReynolds929]

26 psi is really low pressure. Is that what the city is supplying you with? They should be able to tell what the pressure is in the main in front of your house. The low pressure is your main issue, the galvanized pipe is not helping any. Is there a pressure reducing valve on the main anywhere? Have all the aerators been cleaned or replaced?

What you are proposing is fine in my opinion, if it were me I would have the 1" pex trunk and branch to fixtures with 1/2".

I don't see a major improvement happening without solving the low pressure issue.

 

[Rossando]

Copper is copper 40 years ago was better quality but we won't go down that road. Address what you can with new pipe to your house shut off then see/check with the city/county on there scope of work. Most likely they just swap out the meter and won't replace that old galvanized pipework feeding your home. This is where the focus should be once you've finished inside the house. Professionally speaking we start from the main to the house shut off then progress on into the house if necessary.

 

[Reznu]

26 psi is really low pressure. Is that what the city is supplying you with? They should be able to tell what the pressure is in the main in front of your house. The low pressure is your main issue, the galvanized pipe is not helping any. Is there a pressure reducing valve on the main anywhere? Have all the aerators been cleaned or replaced?

What you are proposing is fine in my opinion, if it were me I would have the 1" pex trunk and branch to fixtures with 1/2".

I don't see a major improvement happening without solving the low pressure issue.

no pressure reducing valves. almost all of the faucets are less than 2 years old so didn't see a need to replace aerators regarding the pressure. i actually get 33 psi at the closest spigot to the road. and then 26 at the furthest (about 40ft of pipe between the two) i called once a few years ago and they said 40 psi. and i was going to do 1/2 branch but since the copper is already 1/2in i didn't see any reason between 1/2 or 3/4 so i just went with the size that had more readily available fittings near me (which was 3/4)

 

[Reznu]

Copper is copper 40 years ago was better quality but we won't go down that road. Address what you can with new pipe to your house shut off then see/check with the city/county on there scope of work. Most likely they just swap out the meter and won't replace that old galvanized pipework feeding your home. This is where the focus should be once you've finished inside the house. Professionally speaking we start from the main to the house shut off then progress on into the house if necessary.i

the city actually received some grant or something to do the work, part of improving georgia water quality. in said letter i received it specified they're replacing the city side service line, the meter, and the customer side service line to the house. because they had lead fittings at one point or another which was all replaced but in recent times it was discovered that the lead could have bled into the galvanized pipe/fittings on the customer side. after doing all of this work if the problem is not solved i plan to replace the main from street to house (i just don't want to dig if i don't have to) which is about 70ft.

 

[Rossando]

the city actually received some grant or something to do the work, part of improving georgia water quality. in said letter i received it specified they're replacing the city side service line, the meter, and the customer side service line to the house. because they had lead fittings at one point or another which was all replaced but in recent times it was discovered that the lead could have bled into the galvanized pipe/fittings on the customer side. after doing all of this work if the problem is not solved i plan to replace the main from street to house (i just don't want to dig if i don't have to) which is about 70ft.

Got it, hopefully your all good there