Question on water supply on a duplex

[AndyPA]

So we have run into a slight "speed bump" in a duplex that we are getting ready to rent out. We bought it from estate so there was no detail on any issues with the property. We did due diligence and checked things like electric and plumbing. There were two water meters installed by the water company. Everything seemed OK . . . until this past weekend. A person that had grown up in the house stopped by and wanted to see the house (she lived in Texas and was visiting). She pointed things out that were from when she lived there and it added a backstory to the home (built in 1905). Then she said that they had to coordinate baths / showers / laundry between the two sides as when one did either, the water pressure on the other dropped. Hmmm . . . not good to hear. Well, as I was pressure washing the exterior, my wife ran a load of curtains in the washer and when it filled, my pressure dropped. OK, so the old issue is still an issue.

Fast forward to day. I went in the basement and found that the 3/4" main from the street came in and then teed off to the two meters but necked down to 1/2" copper at the T-junction (3/4" in and two 1/2" out). The meters had 3/4" inlets so it went from 1/2" to an adapter to the meter and from the meter it necked back down to 1/2". This was the case on both sides. Then the entire house is fed from the two 1/2" lines coming out of the meter.

So my question is, if I redo the piping from where it comes in at 3/4" and tee to both meters still at 3/4", out of the meters at 3/4" and only tie into the existing 1/2" copper at the end device points will this help with the water issue? I hate to have to install a new 1 inch or two 1 inch lines if possible but having to have two unrelated tenants coordinate water use is not an option . . . . thanks in advance

 

[Twowaxhack]

The 3/4” main before the two meters are set will be a problem. It’ll always restrict your flow. Each home should have at least a 3/4” line off the main in the street in order to supply each house.

Yes, replacing the lines on your side of the meter would help but you must do Both before and after the meters to completely eliminate your volume drop that’s noticed between the two homes.

You basically have two homes running on one 3/4 line. That sucks.

 

[AndyPA]

The main shutoff valve is upstream of the meter so I can run 3/4" from the valve to each meter and from each meter to the main run on each side. Then tie into the individual devices with 1/2". I guess I can check with the water company to see what a second 3/4" line would run but in lieu of that, would going with 3/4" from the street through the two meters improve the water flow issues . . . . the fact that the water company hooked up the meters makes me question what idiots that they have working for them . . . .

 

[Twowaxhack]

3/4” pipe isn’t big enough to split and run two houses on.

You need a service upgrade from the street.