# replumbing an old house



## pipeguy (Nov 22, 2004)

simonfrog said:


> I have old steel pipe for my water lines right now, some of them look like tree bark where the pipes have rusted, and flaked. I have lines running in every direction, and back again then over up and back again. It is crazy. I have never seen anything like this. I guess what I reallly want to know, is this, is 1" pipe coming into the house, reduced to 3/4 branching to the bathrooms, and reduced to 1/2 coming up through the floor the norm? Is that where I will get my water pressure? Will 1" pvc suffice for this situation? thanks


How's your water pressure now? Are you on a well or is it a public supply?
The house I grew up in was built in the 40's by a couple of farmers and it has plumbing just like you describe. In fact, the water pipes actually "loop" through the house - that is to say they do not dead end anywhere. When I was a kid the house had a well / pump that barely kept up - now it has 'city' water with plenty of pressure. I'm guessing the water piping schematic had something to do with optimizing pressure at the fixture. 
I've seen sprinkled (fire suppression) townhouses serviced by 1" tubing. I can't imagine it's not enough for your needs.


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## Teetorbilt (Feb 7, 2004)

Your problem may be internal. I spent some time as an engineer for a large municipal utilities system and one of the things that really sticks in my mind was a street on a 3/4" water main that was visible along the driveways and as it was being replaced we discovered that the scale buildup had reduced the interior diameter to that of about a pencil! Imagine servicing a dozen homes through a 3/8" waterline! That was what was going on.
Something to look into.


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## Tomm (Feb 9, 2005)

1" pipe should be sufficient A couple of things to keep in mind...reducing the size of a pipe increases the speed of the flow, it does not increase the pressure. The way to increase pressure is to restrict the flow. You will experience pressure drop when running long runs of whatever size pipe you use.


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## DangerMouse (Jul 17, 2008)

hey timberland, this is a DIY site, you _____!

DM


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## Scuba_Dave (Jan 16, 2009)

Digging up a 3 year old thread

That's not spam?
Brain not working?


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## russplmb2 (Jan 30, 2012)

Run a 1" main line. 3/4" to each bathroom. 3/4" to water heater. 3/4" hot water main. I suggest using pex piping. As you branch off to each fixture, go to 1/2" pipe. 

If you have a pressure problem it's likely caused by corrosion on the inside of the old steel pipes. A good way to check for this is to remove an angle stop or hose bib and look inside the pipe.


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## plumberinlaw (Feb 22, 2010)

Dude this post is like 7 years old !:jester:


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