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Discussion Starter · #1 ·
I am planning to replace the exposed galvanized pipe in the basement of an old house. I would connect to the existing supply system for three 1/2" runs behind plaster walls running up to the second floor and for the 3/4" supply line to the house, and replace the rest of the system with CPVC.

Doing a fixture count, the house should require 21.5 fixture units, and the supply travels at least 100 feet from the street to the rest of the system. Table 610.4 suggests a pipe size of at least 1" from the street ("Building supply and branches") is required, rather than the existing 3/4.

It would be a *big* job to replace the supply--driveway, multiple retaining walls and walkways, it probably goes through the garage foundation, etc...

Is there any reason to replace it before we have to? (Does grandfathered undersizing by 2-5 units create any unsafe conditions)?

Is a municipality likely to require us to replace the supply when we get the permit or inspection on the CPVC?
 

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A whole lot faster, easier, and less fittings if you used Pex instead of CPVC.
It also will not crack like CPVC when it freezes.
 
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I am planning to replace the exposed galvanized pipe in the basement of an old house. I would connect to the existing supply system for three 1/2" runs behind plaster walls running up to the second floor and for the 3/4" supply line to the house, and replace the rest of the system with CPVC.

Doing a fixture count, the house should require 21.5 fixture units, and the supply travels at least 100 feet from the street to the rest of the system. Table 610.4 suggests a pipe size of at least 1" from the street ("Building supply and branches") is required, rather than the existing 3/4.

It would be a *big* job to replace the supply--driveway, multiple retaining walls and walkways, it probably goes through the garage foundation, etc...

Is there any reason to replace it before we have to? (Does grandfathered undersizing by 2-5 units create any unsafe conditions)?

Is a municipality likely to require us to replace the supply when we get the permit or inspection on the CPVC?
I would say not likely. However, I don't know your permit offices way of thinking. Mine wouldn't care on an existing service
Size the home as code suggests- you didn't mention elevation change. You gain or loose pressure due to elevation change too. Hopefully you're not on top a hill....
 
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Discussion Starter · #6 ·
A whole lot faster, easier, and less fittings if you used Pex instead of CPVC.
It also will not crack like CPVC when it freezes.
Thank you for the suggestion. I already picked up the CPVC but don't anticipate it being problematic--I haven't used it before but the runs are fairly straightforward, as is the technique.

It was a close call, but I think the deciding factor between PEX and CPVC was the fact that the PEX fittings are proprietary--whereas if you use CPVC, you are much less likely to have to worry about a company going out of business, whether a particular fitting design turned out to be problematic, or whether you'll be able to find someplace that sells the part you need.
 

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Completely wrong on that assumption, it's been around for at least 5 years that I know of, and any new home I've seen being built in this area uses it.
 

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Id have it bored from the basement out to a hole by the street ,then have a new tap done on the main.
That would save tearing up the yard/driveway.:wink:
 
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