I am looking for insight. I am the 3rd owner of a single-story home built in the late 80s. It has 3/4" polybutylene (PB) plumbing running through the attic with 1/2" PB branching off. We have 2 full baths, and of course the kitchen, and 2 spigots outside. The laundry and water heater are located in the garage, near where the main water line enters. In all, I have 12 cold and 7 hot water fittings.

Since 2014, I have had 5 pinhole leaks in various locations in the walls, at least 1 has caused flooring damage. I've had plumbers saying the house needs to be replumbed. Had 2 estimates done; one quote was for $26k (copper), the other for $10k (copper). Neither recommended PEX. Both discouraged it but their reasoning has to do with PB and not PEX.

That being said, as an avid DIYer, I'm looking at doing my own replumbing. I know I want to do a home run system but don't know if I want to do crimp, cinch, or expansion. Any opinion or suggestions?

  • The type of PEX you choose determines the connection procedure. Investigate the subject. Aug 12 '18 at 14:41
  • 2
    Thank you. Been researching for the last 3 months. Toss up between PEX A or PEX B. Since I live in Hawaii I don't have to deal with freezing. I'm guessing with PEX B, i coukd go with the Manabloc manifold. With PEX A it would be an expansion copper manifold. I'm assuming I can't use the Manabloc with PEX A, based on what I've been reading.
    – Datwyl
    Aug 12 '18 at 18:42

If you want to re-plumb with copper you may want to invest or rent a tool to use fittings made by these companies: Nibco press system, Parker Zoom Lock, Ridgid Pro-press, or Viego. I have used 2 of the above and they work great. You cut the copper to length, add the fittings, then use the tool to crimp the fitting and you are done, No soldering. It makes a professional out of a novice. Myself, I would solder or silver braze. (my choice)

  • So, just to clarify - So the plumbers who gave me quotes want to only use copper and not PEX. I, on the other hand, am thinking of using PEX if I do it myself.
    – Datwyl
    Aug 12 '18 at 18:28
  • Since the existing plumbing is in the attic and presumably you'd use the same routes, if there is any chance of freezing, PEX would be the choice over copper. I don't hear of rats or squirrels chewing through PEX but they could if they wanted to. Aug 12 '18 at 19:51
  • Luckily I kive in Hawaii and don't have to deal with major temperature fluctuations.
    – Datwyl
    Aug 13 '18 at 7:10

but don't know if I want to do crimp, cinch, or expansion.

years ago i used wirsbo expansion. I think that has the most going for it in terms of cost- cheaper than the other methods and least tools involved. And to remove all you need is a razor blade to cut through the plastic, being mindful not to score the brass nipple underneath if you plan on reusing that. And that was with the hand tool with a 2' handle, now there's the milwaukee battery powered expander. Either way there's an upfront tool cost, the other methods you're kinda looking at a second tool to buy in order to do any removal. Once the expansion collar was in place, it was very very secure and has zero chance of corrosion like the other methods fwiw and u kind got to really try to install it improperly. It's been a while since I did anything with pex, it has it's problems being plastic and used exclusively in a bldg for plumbing; it's best to maintain some copper some where for copper's natural antimicrobial properties, you can find plenty of stories about problems after some years in service which is why there's a plumber following of no pex only copper. But that's not to say you should never use pex anywhere, just be smart about it. For example, make a run of 3/4" copper straight pipe however long in your attic and branch off that with pex as needed to the endpoints.... any place you can do a straight run of decent length and where it's easy use copper. And if you do that you may likely need only 3/8" pex to run to the faucets, further saving on supply cost. That kind of kills a home run idea, which is more of a marketing gimmick to further sell the idea of pex... it has the mentality of simplicity going for it while using (and selling) more plastic so maybe reconsider the wanting a home run type of install.


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