Ontario Building Code for Plumbing a bathroom in Mississauga

Discussion in 'Canadian Plumbing Code Questions' started by lbgradwell, Feb 20, 2011.

  1. lbgradwell

    lbgradwell New Member

    Oakville, ON
    Hi there,

    I am trying to help a friend reno a powder room in Mississauga, Ontario. I have read the FAQs posted here, but need some clarification...

    The powder room currently has a toilet & a vanity. The toilet drains through a 3" pipe that flows into a 3" main soil stack 4' away. The vanity sink drains into a 2" pipe that joins the 3" toilet pipe 1" from the toilet flange. This vanity drain continues up through the roof to vent.

    We want to install a tub where the toilet is currently, keep the sink plumbing (just replace the sink) and move the toilet to the other end of the room. The toilet will be 8' from the main soil stack.

    Bearing in mind that this is the City of Mississauga:

    1. Can the toilet feed into the main soil stack with no other venting?
    2. If so, what is the limit of the distance of that run?


    If I can do this, my problem is solved. If not I need to know:

    1. If the toilet does require a vent, can I vent it like this?
    2. Are there limits to the distance of any of these runs?


    Many thanks in advance for any advice!!!
    Last edited: Feb 20, 2011
  2. The 2" size you posted for the lav (bathroom sink) drain diameter doesn't make sense. Measure again or explain something more. A sink is usually 1.25", and can be 1.5" pipe diameter. Diameters cannot be increased forever, there are upper limits on these. How did you end up with a 2" on a lav?

    It's a bathroom, so distances are small, but the tub is worrisome, if anything. Your tub can be drained with a pipe of a 1.5" diameter, or you could use a 2" pipe. Smaller diameters = less distance allowed. Larger diameters = more distance allowed. Maximum distances apply to trap arms: you need to measure the tub's trap arm length and post that.

    The length of your 3" drain is not my biggest concern. (A toilet can be drained on a pipe going a long distance, under IPC based codes.) IPC and UPC based codes are all there are. Local variations (Ontario or Mississauga) will not have changed the pipe sizing and distance limits; local variations in codes deal with other stuff (e.g. like materials, like whether to allow homes to have supply lines made of CPVC). In the spirit of helping, I'll tell you that you appear to be learning as you go and not to know enough to be able to describe things well in the first place.
  3. lbgradwell

    lbgradwell New Member

    Oakville, ON
    Thank you for your reply. You are correct that this is a learning process for me; presumably, if I was a plumber, I wouldn't need to ask in the first place! :)

    I'll try to explain better.

    I'm trying to use as much of the existing plumbing as possible, so the tub will be using the 3" pipe the toilet uses currently. The bathroom sink drain itself is 1 1/4', but the plumbing in the wall that it flows into is 2". If that is unusual, all I can say is that the house was built in 1966 and the plumbing has not been touched since! It's definitely 2" and that 2" drain/vent flows into the current 3' toilet pipe (which will be the tub) 1' after the flange.


    In the above picture, the tub is where the toilet is currently. The sink and its plumbing remains as it is and the toilet is the new proposed fixture.

    If the distance of the toilet from that 3" soil stack is 8', can I install it without any further venting required?
  4. DWV is not the part of Code that they change locally. DWV is what your question is.

    Post a to scale diagram in another forum. The general forum. This will get traction. Include the fittings you intend to use for the new toilet arm. This will get you the kind of reaction you want. E.g. yes, confirm, OK.

    Some people know a lot and come to a forum to confirm the fittings and lengths are the right ones. No need to point out that they are not plumbers.

    3" pipe is too large to drain a tub.
Similar Threads: Ontario Building
Forum Title Date
Canadian Plumbing Code Questions Bending K & L hard copper: Is it code legal in Ontario? Apr 17, 2014
Canadian Plumbing Code Questions ABS to Cast Iron - Mechanical Connection Ontario Code Aug 31, 2012
Canadian Plumbing Code Questions Traps and Venting in New Brunswick - old buildings Saturday at 2:46 PM
Canadian Plumbing Code Questions Building inspector says: Dec 9, 2011

Share This Page