Can someone point me in the right direction where in the Ontario Building Code it says that you cannot double trap, like a trap in ABS under a water closet (which has an integrated trap).
Thanks very much.
or for that matter, in any code. They are all very similar. You may have to look for another word like "seal", and see that there are distances and size allowed prior to the seal and then after. After the seal it requires venting and this is also described in the codes. There is no section about what is required in the interval between two seals.
I don't have the Ontario Code but the prohibition against double tapping is almost universal...
No double traps (traps in series)
IRC it is 3201.6 and UPC it is 1004.0
The real question is,,why would you want to install a second trap??