(206) 949-5683, Top Rated Plumber, Seattle
Results 1 to 4 of 4

Thread: Run dedicated 3/4" pex to master shower?

  1. #1
    DIY Junior Member ceiiinosssttuu's Avatar
    Join Date
    Apr 2013
    Location
    Idaho
    Posts
    9

    Default Run dedicated 3/4" pex to master shower?

    I ran one 3/4" hot pex line to the master bathroom which serves a manifold that branches into five 1/2" pex lines. There are 3 fixtures plus 2 shower heads on pressure balancing valves. I don't want to have a pressure drop if both shower heads are going and someone turns on the hot water in the sink, for example. Should I run a separate 3/4" pex hot line that is just dedicated to the master shower? Is that necessary?

  2. #2
    Retired Defense Industry Engineer jadnashua's Avatar
    Join Date
    Sep 2004
    Location
    New England
    Posts
    21,405

    Default

    The key is how much will be running at the same time. One 1/2" pex line feeding two showerheads is close to that tubing's max flow depending on the hot/cold mix. 3/4" pex is somewhat larger than 1/2" copper, and 3/4" copper is probably a good size for a bathroom group. If the pressure drops on the cold side (sink and someone flushes the toilet), that may be enough with 1/2" line to cause a pressure balance valve to throttle the hot side while it's also feeding the shower. Pex is good because it uses fewer fittings, and thus has less friction loss, but volume still depends a significant amount on ID, and copper beats it size-for-size.
    Jim DeBruycker
    Important note - I'm not a pro
    Retired Defense Industry Engineer; Schluter 2.5-day Workshop Completed 2013, 2014

  3. #3
    DIY Junior Member ceiiinosssttuu's Avatar
    Join Date
    Apr 2013
    Location
    Idaho
    Posts
    9

    Default

    Sorry I forgot to mention: I ran two 1/2" pex hots and two 1/2" pex colds to the dual shower. With 3 other fixtures in the bathroom besides these, do I have to worry about a pressure drop if someone uses the sink because the entire bathroom is fed by one 3/4" pex hot and one 3/4" pex cold? Or should I cap off the 1/2" hot lines to the shower and run a dedicated 3/4" pex line to the shower all the way from the 1" main in the mechanical room so it has all the volume to itself?

  4. #4
    Forum Admin, Expert Plumber Terry's Avatar
    Join Date
    Aug 2004
    Location
    Bothell, Washington
    Posts
    14,202
    Blog Entries
    1

    Default

    You are fine with what you have done.
    You did right by running 3/4" to the manifold, and then running 1/2" to each fixture. You're golden!

Similar Threads

  1. How to plan for new master-shower?
    By benze in forum Shower & bathtub Forum & Blog
    Replies: 10
    Last Post: 07-25-2012, 12:50 PM
  2. Neo Angle Shower advice needed... Where to put shower head or 2 maybe? MASTER
    By Jon Wawra in forum Shower & bathtub Forum & Blog
    Replies: 3
    Last Post: 06-22-2011, 12:33 PM
  3. manabloc with master shower
    By freebird_wr in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 4
    Last Post: 05-03-2011, 09:08 PM
  4. Why a tub spout in a dedicated shower?
    By taysan in forum Plumbing Forum, Professional & DIY Advice, Tips & Tricks
    Replies: 2
    Last Post: 04-30-2008, 06:03 PM
  5. Add master "bath"
    By pachai in forum Toilet Forum discussions
    Replies: 4
    Last Post: 07-28-2005, 03:26 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •