Preferences for Hot & Cold Water Line Layout and Piping Connections
Hi everyone. I was watching this video from Matt Risinger called “Controversial Plumbing Innovations 2024” and they talked about the benefits of a “home-run” plumbing system – IE there are no connections within the walls or floors, it’s just one pipe from the hot water tank to the fixture. They also feature a product that you use to bend the Pex pipe as it comes out of the wall at the fixture so you don’t have to connect it to a copper stub-out.
https://www.youtube.com/watch?v=w3Ra23f24yg&t=18s
(Watch for the “Oops” moment with Matt bending pipe)
I can see the benefits from this design, but when you’re designing your plumbing layouts, do you generally prefer this design, a manifold layout, a trunk & branch layout or something else? Maybe a recirculating loop?
I was also intrigued with the new Sharkbite Max fitting (which seems to solve a lot of problems with the water flow being constricted with the older style of fitting) – minute 9:20 in the video. Has anyone used them yet?
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This question has come up here before. What this usually comes down to is how long are your runs, and what is the configuration of the layout? If you have a bunch of fixtures in a relatively straight line, then a single "main with taps" type of arrangement is probably better (at least from an installation standpoint). If you have all your fixtures distributed around radially from a central mechanical room, then a home run system makes the most sense.
Usually you'll be somewhere in between those two extremes. The usual goal is to try to balance material and labor costs for the installation, then install whichever layout is cheaper/easier in your particular home. You can do a sort of hybrid design too, with a few home runs for close by fixtures, and a longer main run that has more distant fixtures tapped off of it. It's hard to say which way will work best without seeing a floorplan drawing with mechanicals indicated.
There are some other concerns you may have too. Sometimes "how fast will I get hot water?" comes up, in which case remember that a home run system can usually use smaller pipes, which heat up faster, but it can't really use a recirculating system, so you can't ever make it "instant". Home run systems allow for future maintenance to be done more easily too, since the central manifold lets you shut off water to only the fixture you're working on, leaving the rest of the house "powered up" for water service.
Bill