Design Plans For Utility Sink And Washer in Basement

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by essjay, Nov 12, 2012.

  1. essjay

    essjay New Member

    Messages:
    23
    Location:
    Pennsylvania
    Gents,

    First time poster, long time site reader. You all do a great job here. Good reference information for us DIY types, in keeping everybody safe and within established standards. Thanks for that!!

    I am in the process of moving my washer and utility sink to another wall in the basement. The current washer and utility sink connections are in the basement concrete floor and the washer drains by backfilling through the utility sink drain and then gravity draining (due to no venting, I assume).

    My design has the utility sink and washer moved to the same wall where a 3" copper DWV is. This DWV services a 1st floor bathroom toilet, shower, and sink only. I have had 2 plumbers look at connecting into the 3" copper DWV and both said in can be done. That said, I have a few questions as I have never done this, although I am an avid DIY type that has taken on multiple projects and am determined to 'do it right'.

    The questions are as follows:

    (1) Any glaring problems with this design (attached drawing)?

    (2) What is the best way to cut 3" copper DWV? hacksaw, sawsall, etc?

    Further information.
    - The total distance from the DWV to the utility sink is 2.5ft and the washer drain is 5'. Would a need exist for a vent at all here?
    - The main sewer drain to the street is directly below the 3" DWV, so does this influence the desing in any way?


    Thank you for your time.
  2. essjay

    essjay New Member

    Messages:
    23
    Location:
    Pennsylvania
    ooops. Not intuitively obvious here. Lets try this as attachment....

    plan.jpg
  3. dlarrivee

    dlarrivee New Member

    Messages:
    1,172
    Location:
    Canada
    When I have to cut into a line that is in place already, I use a sawzall.

    I usually put a hose clamp around the pipe with the edge of it where I need the cut, and I use the hose clamp to guide the blade. Even in awkward positions, I can still get a perfectly square clean cut.
  4. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,260
    Location:
    Land of Cheese
    From what you have stated, the 3" line is a drain for fixtures on the floor above. This means that it cannot be used as a vent. Your basement plumbing needs a dry vent going up through the roof. Alternatively, a new vent could be connected to the existing stack, but the connection would have to made at least 6" above the flood rim of the highest fixture draining into the stack.
  5. Terry

    Terry Administrator Staff Member

    Messages:
    15,298
    Location:
    Bothell, Washington
    You will need to vent both the washer and the sink, and not by using the nearby waste stack.
    The two vents can combine at 42" above the floor, and then either go through the roof, or to a vent on the "next" floor at 42" above that floor.

    [​IMG]

    The pipes above the santee are all vents. The wast line goes through the floor.
    Last edited: Nov 13, 2012
  6. essjay

    essjay New Member

    Messages:
    23
    Location:
    Pennsylvania
    All,

    Thank you for the quick responses.

    Other than venting changes that have been stated, the design and fixtures used generated no cautionary responses, so I assume they are within guidelines established.

    One other question here...what is the best way to permanently seal the current washer and utility sink drains after the lines have been cut flush with the concrete floor? I am thinking to go the route of stuffing a rag or something partially into the drainline and filling with a hydraulic cement. Any preferred method here?

    Thanks again.
  7. essjay

    essjay New Member

    Messages:
    23
    Location:
    Pennsylvania
    Now that Ive been thinking about this venting issue I have an additional question, but which needs further background information regarding this houses design...

    To the left of the referenced DWV vent is a basement bathroom, which has a sink, toilet, and shower. This space is separated by a wood framed wall. All the bathroom fixtures are against a center concrete block support wall, which supports the floor joists of the first and second floors (it is a cape cod style home built in the 60's). In the rear of the house there is another 3" DWV which services the kitchen and 2nd floor bathroom. I assume then that this drain line then connects under the basement concrete floor with the first DWV I referenced and proceeds to the street sewer line.

    I was laying insulation in the front of the attic awhile back and noticed a copper 3" line coming up from the first floor bath to the roof and am sure this is the vent line to the first floor bathroom fixtures. My assumption regarding the second DWV in the rear of the house is that it runs also to the roof to provide venting for the 2nd floor bathroom fixtures.

    Whew. So, my question is how the basement bathroom, which looks to be original to the house (no concrete repairs in the floors that I have seen), was allowed to pass inspection in the first place if no basement venting was used? Could the basement bathroom be using what I have read as a 'wet vent' system through the existing DWV's? (I don't believe they ran a vent line through the concrete block and connected to the first floor bathroom vent line). There are no slow-drain issues with this bath either!?

    Thanks again for all the assistance.
  8. cacher_chick

    cacher_chick Test, Don't Guess!

    Messages:
    3,260
    Location:
    Land of Cheese
    It is not permitted to wet vent between floors. The existing bath would have been required to have venting. If it does not, it was probably not inspected, as there has never been a bath built to code that does not have any venting. Sometimes inspectors overlook things, as do us all.
  9. dlarrivee

    dlarrivee New Member

    Messages:
    1,172
    Location:
    Canada
    Cutting the pipe flush with the floor means you could never properly seal it up, if you really insist upon it, I'm sure you could fill them w/ concrete if feel it comfortable doing it.
  10. essjay

    essjay New Member

    Messages:
    23
    Location:
    Pennsylvania
    CC,

    Well, my only explanation to this then is I guess it was missed. In order to fix this I would require a 3" vent for the toilet according to what I've read. Then, since there is a bath/shower and sink these could be attached to the toilet 3" vent and then connected into the existing 3" vent for the 1st floor bath (or run a new vent alltogether). A 3" vent would be more than enough according to the d.f.u requirements I have read about. In addition, the washer and utility sink could be routed into this new vent also.

    No wonder when a simple project becomes very complicated to people take the easiest route, as the alternative can be very painful, both from a cost and work standpoint. No faults here, its what I 'inherited' when I became the homeowner.

    An interim soultion would then be to route a separate 1 1/2" vent line strictly for the utility sink and washer and at a later date (when/if the first floor bath is upgraded) correct the basement bathroom issues. The downside here is if I dont do it and wind up selling the property later, the next homeowner would not know to do this, potentially even if 'professionals' are brought in, as they are only looking at upgrading the 1st floor bath.

    This is a prime example as to why things are the way they are with houses these days.

    Thanks again.

    can of worms....
  11. essjay

    essjay New Member

    Messages:
    23
    Location:
    Pennsylvania
    dl,

    Can you recommend a better/more satisfactory solution to this problem? I plan on covering the drain eventually with some type of engineered flooring and would prefer it not stick through the floor. But, I do not want potential seeping/leak issues at a later date if I have a backup in the main drain, as this point could potentially be a 'weak' one if not properly handled. Concrete was the only option I thought of, although this does 'shrink' and that would also be a potential problem.

    Thanks.
  12. essjay

    essjay New Member

    Messages:
    23
    Location:
    Pennsylvania
    Just had another 'moment' concerning this vent issue....

    Vents are to require air flow AFTER a p-trap (from what I have read/seen), so the only possible explanation to the exisiting plumbing is that the original 3" DWV referenced is providing both the vent for the basement bathroom. Then, the only logical solution is to vent next to the original 3" DWV and run a new vent line. I could only ASS-U-ME here that, at the time, the reasoning was that since this 3" DWV is way more than adequate to service the 3 fixtures in the 1st floor bathroom that back then (think 1960s) it was sufficient to also provide venting services to the basement bath. Any old timers (my age) that can enlighten here??
  13. dlarrivee

    dlarrivee New Member

    Messages:
    1,172
    Location:
    Canada
    You'll likely need to chip away some concrete around the line itself, and install a cleanout cap/fitting, and then patch the concrete around the line.
  14. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,048
    Location:
    Cave Creek, Arizona
    My initial though after reading as much of the above postings as I could take, is that you are out of your "comfort zone", and may be "exceeding your level of incomptence". In your original drawing, the sink is NOT vented and you cannot tie the vent back into the drain line. As far as existing vents are concerned, you apparently do not know what you have and we cannot tell you HOW you can vent the new washer/sink location.
  15. Terry

    Terry Administrator Staff Member

    Messages:
    15,298
    Location:
    Bothell, Washington
    I would guess that the existing plumbing hidden in the walls is in fact plumbed properly. Just because you see one or two vents through the roof, that doesn't tell you what the plumber has done in the walls.

    Here is a drawing showing two bathrooms stacked with only one vent. Does seeing one vent through the roof tell you anything?

    [​IMG]
  16. Hammerlane

    Hammerlane Member

    Messages:
    262
    Location:
    Ohio
    As mentioned by others, you cannot re-vent into that stack the way you propose. The photo below was on the site about a year ago and is a pretty good example of a washing machine/ utility sink drain setup. This photo assumes that above fitting "A", no other fixtures from above floors are draining into that stack.

    Attached Files:

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