Water Softener Drain Line Question

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Nezil, Jul 11, 2014.

  1. Nezil

    Nezil Member

    Messages:
    35
    Location:
    California
    I realise that this question could equally well be posted in the Water Softener sub-forum, but since the issue is related to the plumbing, rather than the softener itself, I thought it might get more eyes in this one.

    For reference, my original thread regarding softener sizing can be found here:

    Now that I've (almost) decided on a softener, it's time to start thinking about the location of the plumbing required for installation. I'm going to be putting the softener in the corner of the garage, since that is where the main water line enters the home. The photos here show the location I'm thinking of, and also the water piping for the automatic sprinkler system, and it's flow detector.

    Garage corner location:
    [​IMG]
    Thankfully the sprinkler system is separated from the rest of the house outside, so I don't need to worry about flow rate for the sprinklers:
    [​IMG]
    The property has no stub outs for a softener, and all of the pipe work into the home is boxed in just inside the garage door. There is going to be quite a bit of work cutting the drywall and coupling in the softener, but I'm not too concerned about that.

    My bigger concern is the drain line, because there is no existing standpipe, or drain in the garage at all. The photo below is taken of the side wall of the garage, and does show a drain coming down the side of the wall; I believe this is from the kitchen above.
    [​IMG]
    Close Up:
    [​IMG]
    At first, it would seem most appropriate to tap a small P-trap into this drain, and make repairs to the drywall afterwards, but I'm concerned about venting. This drain is obviously vented already, but I'm now lower than the vent, and there are no additional vents anywhere nearby.

    The other alternative is in the crawl space at the back of the garage, where there are two drain stacks available, one has a cap that could be removed (This one is further away, and would be much more complicated and expensive to work with):
    [​IMG]

    And the other has a clean out/cap that could be utilised:
    [​IMG]
    My question then, is this: What would be the best approach to connect the drain line, keeping in consideration that there probably ought to be an air gap, and almost certainly needs to be a P-trap of some sort.

    My primary interest is keeping everything safe, dry and clean, but I'd like to stay to code as well if at all possible. My house is located in the Northern Californian city of Sunnyvale if that helps at all.
  2. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,825
    Location:
    Cave Creek, Arizona
    Don't you have a washing machine somewhere. Draining into its "P" trap/riser will be preferable to any of the options you listed. And will have less chance of backing up and flooding the area.
  3. Nezil

    Nezil Member

    Messages:
    35
    Location:
    California
    Unfortunately, the garage, where the water enters, is the lowest point in the house, and the laundry room is actually on the third floor.

    I do realize that there isn't an easy answer, but just need advice on a solution.
  4. Nezil

    Nezil Member

    Messages:
    35
    Location:
    California
    I've heard from my softener thread, that I'm able to go up 8' from the drain outlet, but this doesn't really help unfortunately.

    My issue is that there is no existing pipe where I can put the drain water into. It would be very complex, and probably more than 8' up to find an existing drain with a P-trap.

    The only drains that I have is either of the two stacks coming out of the slab in the crawl space (about 30' across from the softener installation, and about 1' off the base of the slab), and the drain pipe that's half coming out of the wall in the garage (about 10' across and 3' off the base of the slab). Neither of these options have an existing P-trap or a vent, which makes it problematic.
  5. Reach4

    Reach4 Well-Known Member

    Messages:
    2,412
    Location:
    IL
  6. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,825
    Location:
    Cave Creek, Arizona
    Your concern is that if the drain gets obstructed any "P" trap you install could overflow onto the floor.
  7. Nezil

    Nezil Member

    Messages:
    35
    Location:
    California
    Yes, that's absolutely my concern.

    I'm wondering if the best bet, though it's not to code, would be to go into the clean out in the crawl space, with a reducing bushings down to the size of the drain line, and then install a check valve rather than an air gap. Does a check valve work as a P-trap as well, or am I going to need one of these as well?

    I'm also worried that without a true vent, I'm going to risk the P-trap syphoning out. It's unlikely I guess, since I'll be using probably 1" waste pipe, going into a 3" stack, but it is still possible.
  8. Nezil

    Nezil Member

    Messages:
    35
    Location:
    California
    OK, I think I’ve found a solution…

    Pulling the insulation away in the floor space below the downstairs restroom, I can see the drain and water lines going to the wash basin; photos below.

    [​IMG]
    [​IMG]

    What’s interesting is that the drain line appears to be going at an angle through the corner of the floor and the back wall, with a pretty large gap around it (You can just about make out the painted drywall above the drain). I’m pretty sure that I can get the drain line through the gaps around the existing pipes, and from there out through the back of the wash basin cabinet.

    [​IMG]

    I do need to work out how I’m going to create a stand pipe with air gap in the relatively tight space between the P-Trap and the down pipe of the basin. It looks like I’ll have to replace the trap entirely, because it appears to have been welded together.

    If this all works out, it’s a run of about 30 feet horizontally, and a maximum of about 2 feet up. It’s quite a relief to have gotten this far actually.

    As an aside, I bought a MAP//Pro Turbotorch SWT-9, a couple of feet of 1/2” copper and some fittings today, just to practice soldering in advance of all of the expensive 1-1/4” parts that I’m going to be working with. I really didn’t find it difficult at all. This might be because the Turbotorch is an absolute beast! It takes literally about 10 seconds to heat up 1/2” copper enough to solder. I’m not actually looking forward to working with the 1-1/4” parts, rather than being apprehensive.

    P.S. Apologies if I’m using British terms (wash basin, toilet etc.); I am British, and after living here for nearly 3 years, I’m still finding new words that I thought were international that turned out to be British.
  9. Nezil

    Nezil Member

    Messages:
    35
    Location:
    California
    I’ve now ordered a 1-1/4” OD chrome plated brass threaded branch tailpiece. I’m planning to use this to tap into the lavatory sink drain that I sent pictures of yesterday.

    The tail is 3/4”, and my softener drain line is most likely going to be 5/8” Poly tubing. A rubber adapter clamp will probably be enough to join the drain to the branch, but I’m considering a Gap-A-Flow to make sure that I have an air gap - this would be installed as high as possible under the sink.

    I realise that this is probably still not to code, because the air gap is lower than the sink, so any liquids draining from the sink could flow out of the air gap if the drain blocks. Having said that, I cannot think of any alternatives at this point. How about a 5/8” check valve rather than an air gap?
  10. Nezil

    Nezil Member

    Messages:
    35
    Location:
    California
    My parents were kind enough to order the system parts that I needed for my softener install, and I spent a few weeks planning and ordering pipe components ready for the install (setup discussion in another thread here). I spent most of yesterday doing the install and it's all working, and best of all... no leaks; not bad for first time soldering copper pipe!

    Here are some photos:

    1-1/4" Falcon Flex Lines simplified the install a lot!
    [​IMG]

    Main water line
    [​IMG]

    Feed lines inside the wall
    [​IMG]

    New lowest point faucet installed
    [​IMG]

    Drain line
    [​IMG]
  11. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,226
    Location:
    Maine
    It's not legal to use the lav drain for the softener drain line.
  12. LLigetfa

    LLigetfa DIYer, not in the trades

    Messages:
    4,054
    Location:
    NW Ontario, Canada
    Not sure why not since a dishwasher can be hooked up to a kitchen sink like that. Still, I'd be worried about the drain backing up and overflowing the sink.
    Around here, country folk don't usually send the water to the septic tank.
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