Possibly running new water supply line into old house

[Old home owner]

My city is renovating the water main that services a 100-year-old rental house I own. A new pressure reducing valve will be installed between the water meter and the house. I believe the line supplying the home is as old as the house. I am worried that when the pressure reducing valve is installed, the supply line to the house will break or crumble or burst or otherwise become worthless.

I am investigating having a new supply line installed while the city work is being done. I am worried, however, about downstream effects of replacing the supply line.

- If I replace the supply line with new pipe, what are possible risks at the connection between this new supply line and the existing intake pipe for the house?
- If I replace the supply line with new pipe, what are possible risks for the internal water lines?

I am also considering having interior water lines replaced.

The house has virtually no crawl space except for maybe 80 square feet at one side of the house - on the other side of the house from where the supply line enters the home. Is there any way to replace the lines servicing the utility room, bathroom and kitchen without ripping up the floor of the home?

I hope I have explained my situation well enough.

Any thoughts? Tips? Recommendations? Anyone else go through similar situations?

 

[OttoW]

As for possible damage to the line between the street and your house, it would largely depend on what pressure the city will be supplying water to you (after it's replaced the main). More than likely, it'll be close to the psi that currently have. If that'll be the case, and if your entire system (lines before and throughout house) has been able to handle the pressure, then you should be fine (and only subject to future normal wear and tear of pipes as you were all along). However, in the unlikely event that the city will be greatly increasing the psi to your house, then I'd continue with the installation of a pressure reducer (setting it no higher than what you've always gotten from the street since you know the interior plumbing has been able to handle that level of pressure). Then I'd see whether you've got any problems with the street-to-house line. If it gives at all, it's because of the city's new (much higher) pressure. This new pressure that'll be in the line won't get any higher because of your pressure reducer - the psi doesn't get higher (on the street side of your reducer) simply because it's being restricted or even shut off on your end. I wouldn't spend the money or time to replumb anything until you go through the above scenarios.

As for new plumbing under a house that has very little access, first check that there aren't any access points tucked away on the floor in different parts of the house (e.g. in closets, utility rooms, under staircases). Builders sometimes created these access areas so that underhouse plumbing work/repairs could be performed without tearing up floors. If you don't have any access points, then you'll probably need to create some ( and then snake plumbing lines through them). Do this by laying out your house's floor plan with various plumbing areas (baths, kitchen, washer, water heater, etc.) marked. Then identify the fewest number of centrally located access points to create. You may need to do some initial probing in each proposed access point to ensure there isn't a major physical obstacle under the floor at that point. Bottom line, if you don't already have access points, you'll have to remove some of your home's flooring - but not even close to the entire floor.

Good luck.