Existing 1/2"

Discussion in 'Plumbing Forum, Professional & DIY Advice, Tips & ' started by exeunt, Jun 22, 2010.

  1. exeunt

    exeunt New Member

    Messages:
    27
    Location:
    Stouffville, Ontario, Canada
    So I'm 95% of the way through the plumbing on our new shower and was about to T off my existing line when I thought I wanted to check with someone about supply capacity.

    I currently have a '73 house with 3/4" copper feeding the house, going through our water softener and then splitting off into two 1/2" lines for hot and cold. From that split, the entire house is done using 1/2" copper. The specific run of 1/2" I'm splitting off feeds a bath, two toilets, two sinks and now a shower.

    We haven't had any problems with water pressure, and we are adding a shower in our ensuite so we don't need to use the guest bath anymore, so we don't anticipate too much parallel use of the fixtures. Changing the 1/2" to 3/4" would be a big deal on a relatively small project. Is it against code to split off the 1/2" to feed the shower? Is it highly recommended not to?

    Thanks
  2. johnjh2o1

    johnjh2o1 Plumbing Contractor for 49 years

    Messages:
    1,141
    Location:
    South*East
    The rule of thumb is to not put two fixtures on 1/2". It should be piped with 3/4' mains with 1/2" branches to each fixture.

    John
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,253
    Location:
    Cave Creek, Arizona
    pipe

    IF 1/2" is all you have, then that is what you use. IF it were "illegal" then all of your other piping is wrong also. You may have flow/volume problems because of the smaller supply lines, but you should have those already, so if you live with it now, you will with the new shower also.
  4. exeunt

    exeunt New Member

    Messages:
    27
    Location:
    Stouffville, Ontario, Canada
    I know in some cases codes change, and doing renovations require you to follow those codes. I was concerned that I might be breaking a new code. I'm thinking of running the dedicated 1/2" down to the basement, that way in the future if it was a problem, I could introduce the 3/4" in the basement and not have to break through walls to get it upstairs.
  5. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,253
    Location:
    Cave Creek, Arizona
    In the first place, the only time renovations require upgrading to the new code, other than for the specific item you are working on, is when the renovation creates extensive revision to the existing structure. You do NOT have to repipe the entire house just because you are changing the shower faucet.
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