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Copper pipe sizing

1383 Views 8 Replies 6 Participants Last post by  tylernt
Hello all, and thank-you in advance for any replies!
I'm about to start replumbing my house and would like a little piece of mind that what I'm planning is OK to do. Currently I have a 3/4 main line coming into my single story home. Immediately after the water heater both the cold and hot supply lines drop down to 1/2. I'm kinda getting tired of getting burn when someone flushes the toilet while taking a shower ;) I'm planning on bumping the supply lines up to 3/4 and adding a water softener. The result will be something like this. 3/4 coming into the house and branching of 3/4 for the softener and heater, then having 3 separate 3/4 supply lines. 1 for hard water, 1 for soft cold and 1 for soft hot water. I will be branching off the supply lines with 1/2 for each fixture. My main worry, would be over taxing the single 3/4 main coming into the house by dividing it into 3 lines. Would this cause any problems? If it matter, all 3 supply lines will be about 20' long and each line will supply as follows:
Hard line - 1 outside spigot, toilet, cold kitchen sink/ice maker.
cold soft - 1 bath, 1bath sink.
hot soft - 1 bath, 1 bath sink, 1 kitchen sink w/ dishwasher.
3/4 might be over kill, but I'm getting some from my Bro that I would like to use. Also leaves room for upgrades ;)
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The ony line I would connect up to hard water would be the outside faucet, you do not want rust stains in the toilet and in the ice.
Using 3/4 for all your main runs will have no bad effects, and will increase the avalible flow.
Why copper and not Pex? Cheaper, a whole lot faster to install, far less fittings used, less likly to burst if it freezes.
Why dont you use Pex and a home run manifold system? You say "some" pipe from your Bro. enough to offset the savings for a complete replumb with Pex?

If you only have 3/4 coming in, I would just run 3/4 mains, and branch to 1/2 for the fixtures. Acidic water? use Pex, not copper
You may want to check with your local inspector on pex limitations. When my local permit inspector was out checking my copper rough in, I asked him about pex. He said the only limitation was that I, as the homeowner, had to be certified to install pex. He seemed to indicate that HD or Menard's offered classes that you could get certified through. Copper rough is always a bugger. I had a few pinhole leaks. Plus, even though I take the proper protection, open flame in the house is worrisome. I sweat as much as possible in the garage.

Thanks for such quick replies! Last I had heard, copper was my only option with local code, but that was a year or two ago when I first heard about PEX. I'll have to ask.

Now there's something I've never considered. Beepster mentioned pin hole leaks. I'm sure I'll have a few with that many joints (If I stay with copper anyway). So when this thing starts leaking like the titanic, is it usually required to take the joint completely apart? I have done some sweating in the past, but only a few joints and never really ran into that.
He said the only limitation was that I, as the homeowner, had to be certified to install pex. B
Must be something local. Neither the IRC or UPC say you have to be certified to install it. They do say for CSST (for gas lines) you need to be certified. Also the PEX manufacturer may also only honor warranty when installed by a certified installer.
Someone who knows how to sweat copper never "expects" anything to leak, and it usually dosen't. In hearing your experience level, you would have to be daft to go with anything but PEX. There really are no iffs with PEX.

I was taught right with copper and can honestly say I have never had a leak.

Acidic water is hell on copper, so if you have it, forget copper.
And to add, if i had to do copper again, I would use the MAP gas torches, not the propane.

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