pipe size /max length of run for kitchen, Canada Code

[Philbert]

hello
I have been asked to rough in a new kitchen, it has 1 double sink and a dishwasher beside it, the soil pipe is 25 to 30 feet away, I don't want to run 3 inch all the way if it isnt needed , thanks

[hj]

Even IF 1 1/2" would be approved, there is no way I would EVER use it for anything other than a vent. I ALWAYS use 2" minimum for my drain lines.

[Philbert]

the problem I am having is that if I seach online for a quote from the npc I get a vague reference to some "complicated table" in the plumbing code book which I can acces online unless I pay for it or order a copy of the code book for a price of course,if ther is no restriction all the better, although I will likely use 2 inch anyways, ohhh the 25 to 30 foot run is a sloped run not a drop ifin that changes anything

[jimbo]

It is not a "complicated table" at least not in the books down here. Each fixture is desinated by a number which correlates to how much water is likely to go in it. The number is called "fixture units". In the UPC, a kitchen sink is 2 FU. By the simple table, the maximum # of FU on a horizontal 1½" pipe, beyond the trap arm, is ONE. So the sink needs to drain into a 2" lateral. The horizontal length ( with 1/4" per foot slope minimum) is unlimited.

[Doherty Plumbing]

hello
I have been asked to rough in a new kitchen, it has 1 double sink and a dishwasher beside it, the soil pipe is 25 to 30 feet away, I don't want to run 3 inch all the way if it isnt needed , thanks

1.5" is perfectly acceptable as long as you pick up your vent within 6'.

I usually have a 1.5" fixture drain picked up by a 2x1.5x1.5" tee.

[Terry]

I haven't seen 1.5 for kitchens since the 50's in the lower 48, not Canada though.
Here we use 2" until the vent, and then a 1.5" trap arm.

I guess the Canadian code for kitchen plumbing is pretty weak.

[Plumber1979]

im a plumber here in Ontario and its just fine to use 1 1/2 on a kitchen and it 5' for the vent

[mikeplummer]

1-1/2" is fine. trap arm max is 5' (1.5m). cleanout required on fixture drain or union p-trap. cleanouts every 20' (6m).. you'll want to make sure your slope is right to keep a kitchen sink line that long, clear of grease etc.
secondly NPC is not what you need. you need to refer to the Ontario Building Code section 7 - Plumbing